diff options
Diffstat (limited to 'Lib')
195 files changed, 5879 insertions, 2770 deletions
diff --git a/Lib/_collections_abc.py b/Lib/_collections_abc.py index 6477444..6935e55 100644 --- a/Lib/_collections_abc.py +++ b/Lib/_collections_abc.py @@ -459,6 +459,8 @@ Mapping.register(mappingproxy) class MappingView(Sized): + __slots__ = '_mapping', + def __init__(self, mapping): self._mapping = mapping @@ -471,6 +473,8 @@ class MappingView(Sized): class KeysView(MappingView, Set): + __slots__ = () + @classmethod def _from_iterable(self, it): return set(it) @@ -486,6 +490,8 @@ KeysView.register(dict_keys) class ItemsView(MappingView, Set): + __slots__ = () + @classmethod def _from_iterable(self, it): return set(it) @@ -508,6 +514,8 @@ ItemsView.register(dict_items) class ValuesView(MappingView): + __slots__ = () + def __contains__(self, value): for key in self._mapping: if value == self._mapping[key]: diff --git a/Lib/_dummy_thread.py b/Lib/_dummy_thread.py index b67cfb9..36e5f38 100644 --- a/Lib/_dummy_thread.py +++ b/Lib/_dummy_thread.py @@ -140,6 +140,14 @@ class LockType(object): def locked(self): return self.locked_status + def __repr__(self): + return "<%s %s.%s object at %s>" % ( + "locked" if self.locked_status else "unlocked", + self.__class__.__module__, + self.__class__.__qualname__, + hex(id(self)) + ) + # Used to signal that interrupt_main was called in a "thread" _interrupt = False # True when not executing in a "thread" diff --git a/Lib/_pyio.py b/Lib/_pyio.py index d4cfb6e..9058ee6 100644 --- a/Lib/_pyio.py +++ b/Lib/_pyio.py @@ -6,6 +6,7 @@ import os import abc import codecs import errno +import array # Import _thread instead of threading to reduce startup cost try: from _thread import allocate_lock as Lock @@ -662,16 +663,33 @@ class BufferedIOBase(IOBase): Raises BlockingIOError if the underlying raw stream has no data at the moment. """ - # XXX This ought to work with anything that supports the buffer API - data = self.read(len(b)) + + return self._readinto(b, read1=False) + + def readinto1(self, b): + """Read up to len(b) bytes into *b*, using at most one system call + + Returns an int representing the number of bytes read (0 for EOF). + + Raises BlockingIOError if the underlying raw stream has no + data at the moment. + """ + + return self._readinto(b, read1=True) + + def _readinto(self, b, read1): + if not isinstance(b, memoryview): + b = memoryview(b) + b = b.cast('B') + + if read1: + data = self.read1(len(b)) + else: + data = self.read(len(b)) n = len(data) - try: - b[:n] = data - except TypeError as err: - import array - if not isinstance(b, array.array): - raise err - b[:n] = array.array('b', data) + + b[:n] = data + return n def write(self, b): @@ -1065,6 +1083,58 @@ class BufferedReader(_BufferedIOMixin): return self._read_unlocked( min(size, len(self._read_buf) - self._read_pos)) + # Implementing readinto() and readinto1() is not strictly necessary (we + # could rely on the base class that provides an implementation in terms of + # read() and read1()). We do it anyway to keep the _pyio implementation + # similar to the io implementation (which implements the methods for + # performance reasons). + def _readinto(self, buf, read1): + """Read data into *buf* with at most one system call.""" + + if len(buf) == 0: + return 0 + + # Need to create a memoryview object of type 'b', otherwise + # we may not be able to assign bytes to it, and slicing it + # would create a new object. + if not isinstance(buf, memoryview): + buf = memoryview(buf) + buf = buf.cast('B') + + written = 0 + with self._read_lock: + while written < len(buf): + + # First try to read from internal buffer + avail = min(len(self._read_buf) - self._read_pos, len(buf)) + if avail: + buf[written:written+avail] = \ + self._read_buf[self._read_pos:self._read_pos+avail] + self._read_pos += avail + written += avail + if written == len(buf): + break + + # If remaining space in callers buffer is larger than + # internal buffer, read directly into callers buffer + if len(buf) - written > self.buffer_size: + n = self.raw.readinto(buf[written:]) + if not n: + break # eof + written += n + + # Otherwise refill internal buffer - unless we're + # in read1 mode and already got some data + elif not (read1 and written): + if not self._peek_unlocked(1): + break # eof + + # In readinto1 mode, return as soon as we have some data + if read1 and written: + break + + return written + def tell(self): return _BufferedIOMixin.tell(self) - len(self._read_buf) + self._read_pos @@ -1214,6 +1284,9 @@ class BufferedRWPair(BufferedIOBase): def read1(self, size): return self.reader.read1(size) + def readinto1(self, b): + return self.reader.readinto1(b) + def readable(self): return self.reader.readable() @@ -1296,6 +1369,10 @@ class BufferedRandom(BufferedWriter, BufferedReader): self.flush() return BufferedReader.read1(self, size) + def readinto1(self, b): + self.flush() + return BufferedReader.readinto1(self, b) + def write(self, b): if self._read_buf: # Undo readahead diff --git a/Lib/asynchat.py b/Lib/asynchat.py index 6e16891..fc6cabe 100644 --- a/Lib/asynchat.py +++ b/Lib/asynchat.py @@ -285,6 +285,9 @@ class simple_producer: class fifo: def __init__(self, list=None): + import warnings + warnings.warn('fifo class will be removed in Python 3.6', + DeprecationWarning, stacklevel=2) if not list: self.list = deque() else: diff --git a/Lib/asyncore.py b/Lib/asyncore.py index 00a6396..b2ee278 100644 --- a/Lib/asyncore.py +++ b/Lib/asyncore.py @@ -404,20 +404,6 @@ class dispatcher: if why.args[0] not in (ENOTCONN, EBADF): raise - # cheap inheritance, used to pass all other attribute - # references to the underlying socket object. - def __getattr__(self, attr): - try: - retattr = getattr(self.socket, attr) - except AttributeError: - raise AttributeError("%s instance has no attribute '%s'" - %(self.__class__.__name__, attr)) - else: - msg = "%(me)s.%(attr)s is deprecated; use %(me)s.socket.%(attr)s " \ - "instead" % {'me' : self.__class__.__name__, 'attr' : attr} - warnings.warn(msg, DeprecationWarning, stacklevel=2) - return retattr - # log and log_info may be overridden to provide more sophisticated # logging and warning methods. In general, log is for 'hit' logging # and 'log_info' is for informational, warning and error logging. diff --git a/Lib/code.py b/Lib/code.py index f8184b6..6186e04 100644 --- a/Lib/code.py +++ b/Lib/code.py @@ -7,6 +7,7 @@ import sys import traceback +import argparse from codeop import CommandCompiler, compile_command __all__ = ["InteractiveInterpreter", "InteractiveConsole", "interact", @@ -299,4 +300,12 @@ def interact(banner=None, readfunc=None, local=None): if __name__ == "__main__": - interact() + parser = argparse.ArgumentParser() + parser.add_argument('-q', action='store_true', + help="don't print version and copyright messages") + args = parser.parse_args() + if args.q or sys.flags.quiet: + banner = '' + else: + banner = None + interact(banner) diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py index d993fe0..1f41ff9 100644 --- a/Lib/collections/__init__.py +++ b/Lib/collections/__init__.py @@ -20,6 +20,23 @@ from reprlib import recursive_repr as _recursive_repr ### OrderedDict ################################################################################ +class _OrderedDictKeysView(KeysView): + + def __reversed__(self): + yield from reversed(self._mapping) + +class _OrderedDictItemsView(ItemsView): + + def __reversed__(self): + for key in reversed(self._mapping): + yield (key, self._mapping[key]) + +class _OrderedDictValuesView(ValuesView): + + def __reversed__(self): + for key in reversed(self._mapping): + yield self._mapping[key] + class _Link(object): __slots__ = 'prev', 'next', 'key', '__weakref__' @@ -79,6 +96,8 @@ class OrderedDict(dict): link_next = link.next link_prev.next = link_next link_next.prev = link_prev + link.prev = None + link.next = None def __iter__(self): 'od.__iter__() <==> iter(od)' @@ -162,9 +181,19 @@ class OrderedDict(dict): return size update = __update = MutableMapping.update - keys = MutableMapping.keys - values = MutableMapping.values - items = MutableMapping.items + + def keys(self): + "D.keys() -> a set-like object providing a view on D's keys" + return _OrderedDictKeysView(self) + + def items(self): + "D.items() -> a set-like object providing a view on D's items" + return _OrderedDictItemsView(self) + + def values(self): + "D.values() -> an object providing a view on D's values" + return _OrderedDictValuesView(self) + __ne__ = MutableMapping.__ne__ __marker = object() diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py index 07b5225..1299390 100644 --- a/Lib/concurrent/futures/process.py +++ b/Lib/concurrent/futures/process.py @@ -334,6 +334,9 @@ class ProcessPoolExecutor(_base.Executor): if max_workers is None: self._max_workers = os.cpu_count() or 1 else: + if max_workers <= 0: + raise ValueError("max_workers must be greater than 0") + self._max_workers = max_workers # Make the call queue slightly larger than the number of processes to diff --git a/Lib/concurrent/futures/thread.py b/Lib/concurrent/futures/thread.py index f9beb0f..8d6081c 100644 --- a/Lib/concurrent/futures/thread.py +++ b/Lib/concurrent/futures/thread.py @@ -87,6 +87,9 @@ class ThreadPoolExecutor(_base.Executor): max_workers: The maximum number of threads that can be used to execute the given calls. """ + if max_workers <= 0: + raise ValueError("max_workers must be greater than 0") + self._max_workers = max_workers self._work_queue = queue.Queue() self._threads = set() diff --git a/Lib/copy.py b/Lib/copy.py index bb8840e..383609b 100644 --- a/Lib/copy.py +++ b/Lib/copy.py @@ -221,17 +221,15 @@ def _deepcopy_list(x, memo): d[list] = _deepcopy_list def _deepcopy_tuple(x, memo): - y = [] - for a in x: - y.append(deepcopy(a, memo)) + y = [deepcopy(a, memo) for a in x] # We're not going to put the tuple in the memo, but it's still important we # check for it, in case the tuple contains recursive mutable structures. try: return memo[id(x)] except KeyError: pass - for i in range(len(x)): - if x[i] is not y[i]: + for k, j in zip(x, y): + if k is not j: y = tuple(y) break else: diff --git a/Lib/datetime.py b/Lib/datetime.py index 1789714..3c534d0 100644 --- a/Lib/datetime.py +++ b/Lib/datetime.py @@ -1249,12 +1249,6 @@ class time: _check_tzinfo_arg(tzinfo) return time(hour, minute, second, microsecond, tzinfo) - def __bool__(self): - if self.second or self.microsecond: - return True - offset = self.utcoffset() or timedelta(0) - return timedelta(hours=self.hour, minutes=self.minute) != offset - # Pickle support. def _getstate(self): diff --git a/Lib/dbm/dumb.py b/Lib/dbm/dumb.py index 8f48aad..f95ab85 100644 --- a/Lib/dbm/dumb.py +++ b/Lib/dbm/dumb.py @@ -44,7 +44,7 @@ class _Database(collections.MutableMapping): _os = _os # for _commit() _io = _io # for _commit() - def __init__(self, filebasename, mode): + def __init__(self, filebasename, mode, flag='c'): self._mode = mode # The directory file is a text file. Each line looks like @@ -64,6 +64,17 @@ class _Database(collections.MutableMapping): # The index is an in-memory dict, mirroring the directory file. self._index = None # maps keys to (pos, siz) pairs + # Handle the creation + self._create(flag) + self._update() + + def _create(self, flag): + if flag == 'n': + for filename in (self._datfile, self._bakfile, self._dirfile): + try: + _os.remove(filename) + except OSError: + pass # Mod by Jack: create data file if needed try: f = _io.open(self._datfile, 'r', encoding="Latin-1") @@ -72,7 +83,6 @@ class _Database(collections.MutableMapping): self._chmod(self._datfile) else: f.close() - self._update() # Read directory file into the in-memory index dict. def _update(self): @@ -263,20 +273,20 @@ class _Database(collections.MutableMapping): self.close() -def open(file, flag=None, mode=0o666): +def open(file, flag='c', mode=0o666): """Open the database file, filename, and return corresponding object. The flag argument, used to control how the database is opened in the - other DBM implementations, is ignored in the dbm.dumb module; the - database is always opened for update, and will be created if it does - not exist. + other DBM implementations, supports only the semantics of 'c' and 'n' + values. Other values will default to the semantics of 'c' value: + the database will always opened for update and will be created if it + does not exist. The optional mode argument is the UNIX mode of the file, used only when the database has to be created. It defaults to octal code 0o666 (and will be modified by the prevailing umask). """ - # flag argument is currently ignored # Modify mode depending on the umask try: @@ -287,5 +297,4 @@ def open(file, flag=None, mode=0o666): else: # Turn off any bits that are set in the umask mode = mode & (~um) - - return _Database(file, mode) + return _Database(file, mode, flag=flag) diff --git a/Lib/decimal.py b/Lib/decimal.py index 5b98473..6d0b34c 100644 --- a/Lib/decimal.py +++ b/Lib/decimal.py @@ -2523,7 +2523,7 @@ class Decimal(object): end -= 1 return _dec_from_triple(dup._sign, dup._int[:end], exp) - def quantize(self, exp, rounding=None, context=None, watchexp=True): + def quantize(self, exp, rounding=None, context=None): """Quantize self so its exponent is the same as that of exp. Similar to self._rescale(exp._exp) but with error checking. @@ -2546,16 +2546,6 @@ class Decimal(object): return context._raise_error(InvalidOperation, 'quantize with one INF') - # if we're not watching exponents, do a simple rescale - if not watchexp: - ans = self._rescale(exp._exp, rounding) - # raise Inexact and Rounded where appropriate - if ans._exp > self._exp: - context._raise_error(Rounded) - if ans != self: - context._raise_error(Inexact) - return ans - # exp._exp should be between Etiny and Emax if not (context.Etiny() <= exp._exp <= context.Emax): return context._raise_error(InvalidOperation, diff --git a/Lib/difflib.py b/Lib/difflib.py index 7eb42a9..4af88a9 100644 --- a/Lib/difflib.py +++ b/Lib/difflib.py @@ -852,10 +852,9 @@ class Differ: and return true iff the string is junk. The module-level function `IS_LINE_JUNK` may be used to filter out lines without visible characters, except for at most one splat ('#'). It is recommended - to leave linejunk None; as of Python 2.3, the underlying - SequenceMatcher class has grown an adaptive notion of "noise" lines - that's better than any static definition the author has ever been - able to craft. + to leave linejunk None; the underlying SequenceMatcher class has + an adaptive notion of "noise" lines that's better than any static + definition the author has ever been able to craft. - `charjunk`: A function that should accept a string of length 1. The module-level function `IS_CHARACTER_JUNK` may be used to filter out @@ -1298,17 +1297,18 @@ def ndiff(a, b, linejunk=None, charjunk=IS_CHARACTER_JUNK): Compare `a` and `b` (lists of strings); return a `Differ`-style delta. Optional keyword parameters `linejunk` and `charjunk` are for filter - functions (or None): + functions, or can be None: - - linejunk: A function that should accept a single string argument, and + - linejunk: A function that should accept a single string argument and return true iff the string is junk. The default is None, and is - recommended; as of Python 2.3, an adaptive notion of "noise" lines is - used that does a good job on its own. + recommended; the underlying SequenceMatcher class has an adaptive + notion of "noise" lines. - - charjunk: A function that should accept a string of length 1. The - default is module-level function IS_CHARACTER_JUNK, which filters out - whitespace characters (a blank or tab; note: bad idea to include newline - in this!). + - charjunk: A function that accepts a character (string of length + 1), and returns true iff the character is junk. The default is + the module-level function IS_CHARACTER_JUNK, which filters out + whitespace characters (a blank or tab; note: it's a bad idea to + include newline in this!). Tools/scripts/ndiff.py is a command-line front-end to this function. @@ -1679,7 +1679,7 @@ class HtmlDiff(object): tabsize -- tab stop spacing, defaults to 8. wrapcolumn -- column number where lines are broken and wrapped, defaults to None where lines are not wrapped. - linejunk,charjunk -- keyword arguments passed into ndiff() (used to by + linejunk,charjunk -- keyword arguments passed into ndiff() (used by HtmlDiff() to generate the side by side HTML differences). See ndiff() documentation for argument default values and descriptions. """ diff --git a/Lib/distutils/__init__.py b/Lib/distutils/__init__.py index 9463a35..328bea6 100644 --- a/Lib/distutils/__init__.py +++ b/Lib/distutils/__init__.py @@ -13,5 +13,5 @@ used from a setup script as # Updated automatically by the Python release process. # #--start constants-- -__version__ = "3.4.1" +__version__ = "3.5.0a0" #--end constants-- diff --git a/Lib/distutils/command/upload.py b/Lib/distutils/command/upload.py index 180be7c..1fdb456 100644 --- a/Lib/distutils/command/upload.py +++ b/Lib/distutils/command/upload.py @@ -1,11 +1,14 @@ -"""distutils.command.upload +""" +distutils.command.upload -Implements the Distutils 'upload' subcommand (upload package to PyPI).""" +Implements the Distutils 'upload' subcommand (upload package to a package +index). +""" -import sys -import os, io -import socket +import os +import io import platform +import hashlib from base64 import standard_b64encode from urllib.request import urlopen, Request, HTTPError from urllib.parse import urlparse @@ -14,12 +17,6 @@ from distutils.core import PyPIRCCommand from distutils.spawn import spawn from distutils import log -# this keeps compatibility for 2.3 and 2.4 -if sys.version < "2.5": - from md5 import md5 -else: - from hashlib import md5 - class upload(PyPIRCCommand): description = "upload binary package to PyPI" @@ -60,7 +57,8 @@ class upload(PyPIRCCommand): def run(self): if not self.distribution.dist_files: - raise DistutilsOptionError("No dist file created in earlier command") + msg = "No dist file created in earlier command" + raise DistutilsOptionError(msg) for command, pyversion, filename in self.distribution.dist_files: self.upload_file(command, pyversion, filename) @@ -103,10 +101,10 @@ class upload(PyPIRCCommand): 'content': (os.path.basename(filename),content), 'filetype': command, 'pyversion': pyversion, - 'md5_digest': md5(content).hexdigest(), + 'md5_digest': hashlib.md5(content).hexdigest(), # additional meta-data - 'metadata_version' : '1.0', + 'metadata_version': '1.0', 'summary': meta.get_description(), 'home_page': meta.get_url(), 'author': meta.get_contact(), @@ -149,7 +147,7 @@ class upload(PyPIRCCommand): for key, value in data.items(): title = '\nContent-Disposition: form-data; name="%s"' % key # handle multiple entries for the same name - if type(value) != type([]): + if not isinstance(value, list): value = [value] for value in value: if type(value) is tuple: @@ -167,13 +165,15 @@ class upload(PyPIRCCommand): body.write(b"\n") body = body.getvalue() - self.announce("Submitting %s to %s" % (filename, self.repository), log.INFO) + msg = "Submitting %s to %s" % (filename, self.repository) + self.announce(msg, log.INFO) # build the Request - headers = {'Content-type': - 'multipart/form-data; boundary=%s' % boundary, - 'Content-length': str(len(body)), - 'Authorization': auth} + headers = { + 'Content-type': 'multipart/form-data; boundary=%s' % boundary, + 'Content-length': str(len(body)), + 'Authorization': auth, + } request = Request(self.repository, data=body, headers=headers) diff --git a/Lib/distutils/dist.py b/Lib/distutils/dist.py index 7eb04bc..ffb33ff6 100644 --- a/Lib/distutils/dist.py +++ b/Lib/distutils/dist.py @@ -4,7 +4,9 @@ Provides the Distribution class, which represents the module distribution being built/installed/distributed. """ -import sys, os, re +import sys +import os +import re from email import message_from_file try: @@ -22,7 +24,7 @@ from distutils.debug import DEBUG # the same as a Python NAME -- I don't allow leading underscores. The fact # that they're very similar is no coincidence; the default naming scheme is # to look for a Python module named after the command. -command_re = re.compile (r'^[a-zA-Z]([a-zA-Z0-9_]*)$') +command_re = re.compile(r'^[a-zA-Z]([a-zA-Z0-9_]*)$') class Distribution: @@ -39,7 +41,6 @@ class Distribution: See the code for 'setup()', in core.py, for details. """ - # 'global_options' describes the command-line options that may be # supplied to the setup script prior to any actual commands. # Eg. "./setup.py -n" or "./setup.py --quiet" both take advantage of @@ -48,12 +49,13 @@ class Distribution: # don't want to pollute the commands with too many options that they # have minimal control over. # The fourth entry for verbose means that it can be repeated. - global_options = [('verbose', 'v', "run verbosely (default)", 1), - ('quiet', 'q', "run quietly (turns verbosity off)"), - ('dry-run', 'n', "don't actually do anything"), - ('help', 'h', "show detailed help message"), - ('no-user-cfg', None, - 'ignore pydistutils.cfg in your home directory'), + global_options = [ + ('verbose', 'v', "run verbosely (default)", 1), + ('quiet', 'q', "run quietly (turns verbosity off)"), + ('dry-run', 'n', "don't actually do anything"), + ('help', 'h', "show detailed help message"), + ('no-user-cfg', None, + 'ignore pydistutils.cfg in your home directory'), ] # 'common_usage' is a short (2-3 line) string describing the common @@ -115,10 +117,9 @@ Common commands: (see '--help-commands' for more) # negative options are options that exclude other options negative_opt = {'quiet': 'verbose'} - # -- Creation/initialization methods ------------------------------- - def __init__ (self, attrs=None): + def __init__(self, attrs=None): """Construct a new Distribution instance: initialize all the attributes of a Distribution, and then use 'attrs' (a dictionary mapping attribute names to values) to assign some of those @@ -532,15 +533,15 @@ Common commands: (see '--help-commands' for more) # to be sure that the basic "command" interface is implemented. if not issubclass(cmd_class, Command): raise DistutilsClassError( - "command class %s must subclass Command" % cmd_class) + "command class %s must subclass Command" % cmd_class) # Also make sure that the command object provides a list of its # known options. if not (hasattr(cmd_class, 'user_options') and isinstance(cmd_class.user_options, list)): - raise DistutilsClassError(("command class %s must provide " + - "'user_options' attribute (a list of tuples)") % \ - cmd_class) + msg = ("command class %s must provide " + "'user_options' attribute (a list of tuples)") + raise DistutilsClassError(msg % cmd_class) # If the command class has a list of negative alias options, # merge it in with the global negative aliases. @@ -552,12 +553,11 @@ Common commands: (see '--help-commands' for more) # Check for help_options in command class. They have a different # format (tuple of four) so we need to preprocess them here. if (hasattr(cmd_class, 'help_options') and - isinstance(cmd_class.help_options, list)): + isinstance(cmd_class.help_options, list)): help_options = fix_help_options(cmd_class.help_options) else: help_options = [] - # All commands support the global options too, just by adding # in 'global_options'. parser.set_option_table(self.global_options + @@ -570,7 +570,7 @@ Common commands: (see '--help-commands' for more) return if (hasattr(cmd_class, 'help_options') and - isinstance(cmd_class.help_options, list)): + isinstance(cmd_class.help_options, list)): help_option_found=0 for (help_option, short, desc, func) in cmd_class.help_options: if hasattr(opts, parser.get_attr_name(help_option)): @@ -647,7 +647,7 @@ Common commands: (see '--help-commands' for more) else: klass = self.get_command_class(command) if (hasattr(klass, 'help_options') and - isinstance(klass.help_options, list)): + isinstance(klass.help_options, list)): parser.set_option_table(klass.user_options + fix_help_options(klass.help_options)) else: @@ -814,7 +814,7 @@ Common commands: (see '--help-commands' for more) klass_name = command try: - __import__ (module_name) + __import__(module_name) module = sys.modules[module_name] except ImportError: continue @@ -823,8 +823,8 @@ Common commands: (see '--help-commands' for more) klass = getattr(module, klass_name) except AttributeError: raise DistutilsModuleError( - "invalid command '%s' (no class '%s' in module '%s')" - % (command, klass_name, module_name)) + "invalid command '%s' (no class '%s' in module '%s')" + % (command, klass_name, module_name)) self.cmdclass[command] = klass return klass @@ -840,7 +840,7 @@ Common commands: (see '--help-commands' for more) cmd_obj = self.command_obj.get(command) if not cmd_obj and create: if DEBUG: - self.announce("Distribution.get_command_obj(): " \ + self.announce("Distribution.get_command_obj(): " "creating '%s' command object" % command) klass = self.get_command_class(command) @@ -897,8 +897,8 @@ Common commands: (see '--help-commands' for more) setattr(command_obj, option, value) else: raise DistutilsOptionError( - "error in %s: command '%s' has no such option '%s'" - % (source, command_name, option)) + "error in %s: command '%s' has no such option '%s'" + % (source, command_name, option)) except ValueError as msg: raise DistutilsOptionError(msg) @@ -974,7 +974,6 @@ Common commands: (see '--help-commands' for more) cmd_obj.run() self.have_run[command] = 1 - # -- Distribution query methods ------------------------------------ def has_pure_modules(self): @@ -1112,17 +1111,17 @@ class DistributionMetadata: """ version = '1.0' if (self.provides or self.requires or self.obsoletes or - self.classifiers or self.download_url): + self.classifiers or self.download_url): version = '1.1' file.write('Metadata-Version: %s\n' % version) - file.write('Name: %s\n' % self.get_name() ) - file.write('Version: %s\n' % self.get_version() ) - file.write('Summary: %s\n' % self.get_description() ) - file.write('Home-page: %s\n' % self.get_url() ) - file.write('Author: %s\n' % self.get_contact() ) - file.write('Author-email: %s\n' % self.get_contact_email() ) - file.write('License: %s\n' % self.get_license() ) + file.write('Name: %s\n' % self.get_name()) + file.write('Version: %s\n' % self.get_version()) + file.write('Summary: %s\n' % self.get_description()) + file.write('Home-page: %s\n' % self.get_url()) + file.write('Author: %s\n' % self.get_contact()) + file.write('Author-email: %s\n' % self.get_contact_email()) + file.write('License: %s\n' % self.get_license()) if self.download_url: file.write('Download-URL: %s\n' % self.download_url) @@ -1131,7 +1130,7 @@ class DistributionMetadata: keywords = ','.join(self.get_keywords()) if keywords: - file.write('Keywords: %s\n' % keywords ) + file.write('Keywords: %s\n' % keywords) self._write_list(file, 'Platform', self.get_platforms()) self._write_list(file, 'Classifier', self.get_classifiers()) diff --git a/Lib/distutils/extension.py b/Lib/distutils/extension.py index a93655a..cc04a18 100644 --- a/Lib/distutils/extension.py +++ b/Lib/distutils/extension.py @@ -131,6 +131,14 @@ class Extension: msg = "Unknown Extension options: %s" % options warnings.warn(msg) + def __repr__(self): + return '<%s.%s(%r) at %#x>' % ( + self.__class__.__module__, + self.__class__.__name__, + self.name, + id(self)) + + def read_setup_file(filename): """Reads a Setup file and returns Extension instances.""" from distutils.sysconfig import (parse_makefile, expand_makefile_vars, diff --git a/Lib/doctest.py b/Lib/doctest.py index d212ad6..be824f4 100644 --- a/Lib/doctest.py +++ b/Lib/doctest.py @@ -2376,15 +2376,6 @@ def DocTestSuite(module=None, globs=None, extraglobs=None, test_finder=None, suite = _DocTestSuite() suite.addTest(SkipDocTestCase(module)) return suite - elif not tests: - # Why do we want to do this? Because it reveals a bug that might - # otherwise be hidden. - # It is probably a bug that this exception is not also raised if the - # number of doctest examples in tests is zero (i.e. if no doctest - # examples were found). However, we should probably not be raising - # an exception at all here, though it is too late to make this change - # for a maintenance release. See also issue #14649. - raise ValueError(module, "has no docstrings") tests.sort() suite = _DocTestSuite() diff --git a/Lib/encodings/cp65001.py b/Lib/encodings/cp65001.py index 287eb87..95cb2ae 100644 --- a/Lib/encodings/cp65001.py +++ b/Lib/encodings/cp65001.py @@ -11,20 +11,23 @@ if not hasattr(codecs, 'code_page_encode'): ### Codec APIs encode = functools.partial(codecs.code_page_encode, 65001) -decode = functools.partial(codecs.code_page_decode, 65001) +_decode = functools.partial(codecs.code_page_decode, 65001) + +def decode(input, errors='strict'): + return codecs.code_page_decode(65001, input, errors, True) class IncrementalEncoder(codecs.IncrementalEncoder): def encode(self, input, final=False): return encode(input, self.errors)[0] class IncrementalDecoder(codecs.BufferedIncrementalDecoder): - _buffer_decode = decode + _buffer_decode = _decode class StreamWriter(codecs.StreamWriter): encode = encode class StreamReader(codecs.StreamReader): - decode = decode + decode = _decode ### encodings module API diff --git a/Lib/ensurepip/__init__.py b/Lib/ensurepip/__init__.py index 84c2125..4af1b1d 100644 --- a/Lib/ensurepip/__init__.py +++ b/Lib/ensurepip/__init__.py @@ -8,7 +8,7 @@ import tempfile __all__ = ["version", "bootstrap"] -_SETUPTOOLS_VERSION = "2.1" +_SETUPTOOLS_VERSION = "3.6" _PIP_VERSION = "1.5.6" diff --git a/Lib/ensurepip/_bundled/setuptools-2.1-py2.py3-none-any.whl b/Lib/ensurepip/_bundled/setuptools-3.6-py2.py3-none-any.whl Binary files differindex ed77b59..f0ffcfc 100644 --- a/Lib/ensurepip/_bundled/setuptools-2.1-py2.py3-none-any.whl +++ b/Lib/ensurepip/_bundled/setuptools-3.6-py2.py3-none-any.whl diff --git a/Lib/formatter.py b/Lib/formatter.py index d8cca52..769bd6a 100644 --- a/Lib/formatter.py +++ b/Lib/formatter.py @@ -21,7 +21,7 @@ manage and inserting data into the output. import sys import warnings warnings.warn('the formatter module is deprecated and will be removed in ' - 'Python 3.6', PendingDeprecationWarning) + 'Python 3.6', DeprecationWarning) AS_IS = None diff --git a/Lib/fractions.py b/Lib/fractions.py index 79e83ff..43f146f 100644 --- a/Lib/fractions.py +++ b/Lib/fractions.py @@ -70,7 +70,7 @@ class Fraction(numbers.Rational): __slots__ = ('_numerator', '_denominator') # We're immutable, so use __new__ not __init__ - def __new__(cls, numerator=0, denominator=None): + def __new__(cls, numerator=0, denominator=None, _normalize=True): """Constructs a Rational. Takes a string like '3/2' or '1.5', another Rational instance, a @@ -165,9 +165,12 @@ class Fraction(numbers.Rational): if denominator == 0: raise ZeroDivisionError('Fraction(%s, 0)' % numerator) - g = gcd(numerator, denominator) - self._numerator = numerator // g - self._denominator = denominator // g + if _normalize: + g = gcd(numerator, denominator) + numerator //= g + denominator //= g + self._numerator = numerator + self._denominator = denominator return self @classmethod @@ -453,10 +456,12 @@ class Fraction(numbers.Rational): power = b.numerator if power >= 0: return Fraction(a._numerator ** power, - a._denominator ** power) + a._denominator ** power, + _normalize=False) else: return Fraction(a._denominator ** -power, - a._numerator ** -power) + a._numerator ** -power, + _normalize=False) else: # A fractional power will generally produce an # irrational number. @@ -480,15 +485,15 @@ class Fraction(numbers.Rational): def __pos__(a): """+a: Coerces a subclass instance to Fraction""" - return Fraction(a._numerator, a._denominator) + return Fraction(a._numerator, a._denominator, _normalize=False) def __neg__(a): """-a""" - return Fraction(-a._numerator, a._denominator) + return Fraction(-a._numerator, a._denominator, _normalize=False) def __abs__(a): """abs(a)""" - return Fraction(abs(a._numerator), a._denominator) + return Fraction(abs(a._numerator), a._denominator, _normalize=False) def __trunc__(a): """trunc(a)""" diff --git a/Lib/heapq.py b/Lib/heapq.py index d615239..258c0ba 100644 --- a/Lib/heapq.py +++ b/Lib/heapq.py @@ -127,8 +127,6 @@ From all times, sorting has always been a Great Art! :-) __all__ = ['heappush', 'heappop', 'heapify', 'heapreplace', 'merge', 'nlargest', 'nsmallest', 'heappushpop'] -from itertools import islice, count, tee, chain - def heappush(heap, item): """Push item onto heap, maintaining the heap invariant.""" heap.append(item) @@ -141,9 +139,8 @@ def heappop(heap): returnitem = heap[0] heap[0] = lastelt _siftup(heap, 0) - else: - returnitem = lastelt - return returnitem + return returnitem + return lastelt def heapreplace(heap, item): """Pop and return the current smallest value, and add the new item. @@ -179,12 +176,22 @@ def heapify(x): for i in reversed(range(n//2)): _siftup(x, i) -def _heappushpop_max(heap, item): - """Maxheap version of a heappush followed by a heappop.""" - if heap and item < heap[0]: - item, heap[0] = heap[0], item +def _heappop_max(heap): + """Maxheap version of a heappop.""" + lastelt = heap.pop() # raises appropriate IndexError if heap is empty + if heap: + returnitem = heap[0] + heap[0] = lastelt _siftup_max(heap, 0) - return item + return returnitem + return lastelt + +def _heapreplace_max(heap, item): + """Maxheap version of a heappop followed by a heappush.""" + returnitem = heap[0] # raises appropriate IndexError if heap is empty + heap[0] = item + _siftup_max(heap, 0) + return returnitem def _heapify_max(x): """Transform list into a maxheap, in-place, in O(len(x)) time.""" @@ -192,42 +199,6 @@ def _heapify_max(x): for i in reversed(range(n//2)): _siftup_max(x, i) -def nlargest(n, iterable): - """Find the n largest elements in a dataset. - - Equivalent to: sorted(iterable, reverse=True)[:n] - """ - if n < 0: - return [] - it = iter(iterable) - result = list(islice(it, n)) - if not result: - return result - heapify(result) - _heappushpop = heappushpop - for elem in it: - _heappushpop(result, elem) - result.sort(reverse=True) - return result - -def nsmallest(n, iterable): - """Find the n smallest elements in a dataset. - - Equivalent to: sorted(iterable)[:n] - """ - if n < 0: - return [] - it = iter(iterable) - result = list(islice(it, n)) - if not result: - return result - _heapify_max(result) - _heappushpop = _heappushpop_max - for elem in it: - _heappushpop(result, elem) - result.sort() - return result - # 'heap' is a heap at all indices >= startpos, except possibly for pos. pos # is the index of a leaf with a possibly out-of-order value. Restore the # heap invariant. @@ -340,13 +311,7 @@ def _siftup_max(heap, pos): heap[pos] = newitem _siftdown_max(heap, startpos, pos) -# If available, use C implementation -try: - from _heapq import * -except ImportError: - pass - -def merge(*iterables): +def merge(*iterables, key=None, reverse=False): '''Merge multiple sorted inputs into a single sorted output. Similar to sorted(itertools.chain(*iterables)) but returns a generator, @@ -356,51 +321,158 @@ def merge(*iterables): >>> list(merge([1,3,5,7], [0,2,4,8], [5,10,15,20], [], [25])) [0, 1, 2, 3, 4, 5, 5, 7, 8, 10, 15, 20, 25] + If *key* is not None, applies a key function to each element to determine + its sort order. + + >>> list(merge(['dog', 'horse'], ['cat', 'fish', 'kangaroo'], key=len)) + ['dog', 'cat', 'fish', 'horse', 'kangaroo'] + ''' - _heappop, _heapreplace, _StopIteration = heappop, heapreplace, StopIteration - _len = len h = [] h_append = h.append - for itnum, it in enumerate(map(iter, iterables)): + + if reverse: + _heapify = _heapify_max + _heappop = _heappop_max + _heapreplace = _heapreplace_max + direction = -1 + else: + _heapify = heapify + _heappop = heappop + _heapreplace = heapreplace + direction = 1 + + if key is None: + for order, it in enumerate(map(iter, iterables)): + try: + next = it.__next__ + h_append([next(), order * direction, next]) + except StopIteration: + pass + _heapify(h) + while len(h) > 1: + try: + while True: + value, order, next = s = h[0] + yield value + s[0] = next() # raises StopIteration when exhausted + _heapreplace(h, s) # restore heap condition + except StopIteration: + _heappop(h) # remove empty iterator + if h: + # fast case when only a single iterator remains + value, order, next = h[0] + yield value + yield from next.__self__ + return + + for order, it in enumerate(map(iter, iterables)): try: next = it.__next__ - h_append([next(), itnum, next]) - except _StopIteration: + value = next() + h_append([key(value), order * direction, value, next]) + except StopIteration: pass - heapify(h) - - while _len(h) > 1: + _heapify(h) + while len(h) > 1: try: while True: - v, itnum, next = s = h[0] - yield v - s[0] = next() # raises StopIteration when exhausted - _heapreplace(h, s) # restore heap condition - except _StopIteration: - _heappop(h) # remove empty iterator + key_value, order, value, next = s = h[0] + yield value + value = next() + s[0] = key(value) + s[2] = value + _heapreplace(h, s) + except StopIteration: + _heappop(h) if h: - # fast case when only a single iterator remains - v, itnum, next = h[0] - yield v + key_value, order, value, next = h[0] + yield value yield from next.__self__ -# Extend the implementations of nsmallest and nlargest to use a key= argument -_nsmallest = nsmallest + +# Algorithm notes for nlargest() and nsmallest() +# ============================================== +# +# Make a single pass over the data while keeping the k most extreme values +# in a heap. Memory consumption is limited to keeping k values in a list. +# +# Measured performance for random inputs: +# +# number of comparisons +# n inputs k-extreme values (average of 5 trials) % more than min() +# ------------- ---------------- --------------------- ----------------- +# 1,000 100 3,317 231.7% +# 10,000 100 14,046 40.5% +# 100,000 100 105,749 5.7% +# 1,000,000 100 1,007,751 0.8% +# 10,000,000 100 10,009,401 0.1% +# +# Theoretical number of comparisons for k smallest of n random inputs: +# +# Step Comparisons Action +# ---- -------------------------- --------------------------- +# 1 1.66 * k heapify the first k-inputs +# 2 n - k compare remaining elements to top of heap +# 3 k * (1 + lg2(k)) * ln(n/k) replace the topmost value on the heap +# 4 k * lg2(k) - (k/2) final sort of the k most extreme values +# +# Combining and simplifying for a rough estimate gives: +# +# comparisons = n + k * (log(k, 2) * log(n/k) + log(k, 2) + log(n/k)) +# +# Computing the number of comparisons for step 3: +# ----------------------------------------------- +# * For the i-th new value from the iterable, the probability of being in the +# k most extreme values is k/i. For example, the probability of the 101st +# value seen being in the 100 most extreme values is 100/101. +# * If the value is a new extreme value, the cost of inserting it into the +# heap is 1 + log(k, 2). +# * The probabilty times the cost gives: +# (k/i) * (1 + log(k, 2)) +# * Summing across the remaining n-k elements gives: +# sum((k/i) * (1 + log(k, 2)) for i in range(k+1, n+1)) +# * This reduces to: +# (H(n) - H(k)) * k * (1 + log(k, 2)) +# * Where H(n) is the n-th harmonic number estimated by: +# gamma = 0.5772156649 +# H(n) = log(n, e) + gamma + 1 / (2 * n) +# http://en.wikipedia.org/wiki/Harmonic_series_(mathematics)#Rate_of_divergence +# * Substituting the H(n) formula: +# comparisons = k * (1 + log(k, 2)) * (log(n/k, e) + (1/n - 1/k) / 2) +# +# Worst-case for step 3: +# ---------------------- +# In the worst case, the input data is reversed sorted so that every new element +# must be inserted in the heap: +# +# comparisons = 1.66 * k + log(k, 2) * (n - k) +# +# Alternative Algorithms +# ---------------------- +# Other algorithms were not used because they: +# 1) Took much more auxiliary memory, +# 2) Made multiple passes over the data. +# 3) Made more comparisons in common cases (small k, large n, semi-random input). +# See the more detailed comparison of approach at: +# http://code.activestate.com/recipes/577573-compare-algorithms-for-heapqsmallest + def nsmallest(n, iterable, key=None): """Find the n smallest elements in a dataset. Equivalent to: sorted(iterable, key=key)[:n] """ - # Short-cut for n==1 is to use min() when len(iterable)>0 + + # Short-cut for n==1 is to use min() if n == 1: it = iter(iterable) - head = list(islice(it, 1)) - if not head: - return [] + sentinel = object() if key is None: - return [min(chain(head, it))] - return [min(chain(head, it), key=key)] + result = min(it, default=sentinel) + else: + result = min(it, default=sentinel, key=key) + return [] if result is sentinel else [result] # When n>=size, it's faster to use sorted() try: @@ -413,32 +485,57 @@ def nsmallest(n, iterable, key=None): # When key is none, use simpler decoration if key is None: - it = zip(iterable, count()) # decorate - result = _nsmallest(n, it) - return [r[0] for r in result] # undecorate + it = iter(iterable) + # put the range(n) first so that zip() doesn't + # consume one too many elements from the iterator + result = [(elem, i) for i, elem in zip(range(n), it)] + if not result: + return result + _heapify_max(result) + top = result[0][0] + order = n + _heapreplace = _heapreplace_max + for elem in it: + if elem < top: + _heapreplace(result, (elem, order)) + top = result[0][0] + order += 1 + result.sort() + return [r[0] for r in result] # General case, slowest method - in1, in2 = tee(iterable) - it = zip(map(key, in1), count(), in2) # decorate - result = _nsmallest(n, it) - return [r[2] for r in result] # undecorate + it = iter(iterable) + result = [(key(elem), i, elem) for i, elem in zip(range(n), it)] + if not result: + return result + _heapify_max(result) + top = result[0][0] + order = n + _heapreplace = _heapreplace_max + for elem in it: + k = key(elem) + if k < top: + _heapreplace(result, (k, order, elem)) + top = result[0][0] + order += 1 + result.sort() + return [r[2] for r in result] -_nlargest = nlargest def nlargest(n, iterable, key=None): """Find the n largest elements in a dataset. Equivalent to: sorted(iterable, key=key, reverse=True)[:n] """ - # Short-cut for n==1 is to use max() when len(iterable)>0 + # Short-cut for n==1 is to use max() if n == 1: it = iter(iterable) - head = list(islice(it, 1)) - if not head: - return [] + sentinel = object() if key is None: - return [max(chain(head, it))] - return [max(chain(head, it), key=key)] + result = max(it, default=sentinel) + else: + result = max(it, default=sentinel, key=key) + return [] if result is sentinel else [result] # When n>=size, it's faster to use sorted() try: @@ -451,26 +548,60 @@ def nlargest(n, iterable, key=None): # When key is none, use simpler decoration if key is None: - it = zip(iterable, count(0,-1)) # decorate - result = _nlargest(n, it) - return [r[0] for r in result] # undecorate + it = iter(iterable) + result = [(elem, i) for i, elem in zip(range(0, -n, -1), it)] + if not result: + return result + heapify(result) + top = result[0][0] + order = -n + _heapreplace = heapreplace + for elem in it: + if top < elem: + _heapreplace(result, (elem, order)) + top = result[0][0] + order -= 1 + result.sort(reverse=True) + return [r[0] for r in result] # General case, slowest method - in1, in2 = tee(iterable) - it = zip(map(key, in1), count(0,-1), in2) # decorate - result = _nlargest(n, it) - return [r[2] for r in result] # undecorate + it = iter(iterable) + result = [(key(elem), i, elem) for i, elem in zip(range(0, -n, -1), it)] + if not result: + return result + heapify(result) + top = result[0][0] + order = -n + _heapreplace = heapreplace + for elem in it: + k = key(elem) + if top < k: + _heapreplace(result, (k, order, elem)) + top = result[0][0] + order -= 1 + result.sort(reverse=True) + return [r[2] for r in result] + +# If available, use C implementation +try: + from _heapq import * +except ImportError: + pass +try: + from _heapq import _heapreplace_max +except ImportError: + pass +try: + from _heapq import _heapify_max +except ImportError: + pass +try: + from _heapq import _heappop_max +except ImportError: + pass + if __name__ == "__main__": - # Simple sanity test - heap = [] - data = [1, 3, 5, 7, 9, 2, 4, 6, 8, 0] - for item in data: - heappush(heap, item) - sort = [] - while heap: - sort.append(heappop(heap)) - print(sort) import doctest - doctest.testmod() + print(doctest.testmod()) diff --git a/Lib/http/client.py b/Lib/http/client.py index d2013f2..ad5590c 100644 --- a/Lib/http/client.py +++ b/Lib/http/client.py @@ -270,7 +270,7 @@ def parse_headers(fp, _class=HTTPMessage): return email.parser.Parser(_class=_class).parsestr(hstring) -class HTTPResponse(io.RawIOBase): +class HTTPResponse(io.BufferedIOBase): # See RFC 2616 sec 19.6 and RFC 1945 sec 6 for details. @@ -495,9 +495,10 @@ class HTTPResponse(io.RawIOBase): return b"" if amt is not None: - # Amount is given, so call base class version - # (which is implemented in terms of self.readinto) - return super(HTTPResponse, self).read(amt) + # Amount is given, implement using readinto + b = bytearray(amt) + n = self.readinto(b) + return memoryview(b)[:n].tobytes() else: # Amount is not given (unbounded read) so we must check self.length # and self.chunked @@ -577,71 +578,67 @@ class HTTPResponse(io.RawIOBase): if line in (b'\r\n', b'\n', b''): break + def _get_chunk_left(self): + # return self.chunk_left, reading a new chunk if necessary. + # chunk_left == 0: at the end of the current chunk, need to close it + # chunk_left == None: No current chunk, should read next. + # This function returns non-zero or None if the last chunk has + # been read. + chunk_left = self.chunk_left + if not chunk_left: # Can be 0 or None + if chunk_left is not None: + # We are at the end of chunk. dicard chunk end + self._safe_read(2) # toss the CRLF at the end of the chunk + try: + chunk_left = self._read_next_chunk_size() + except ValueError: + raise IncompleteRead(b'') + if chunk_left == 0: + # last chunk: 1*("0") [ chunk-extension ] CRLF + self._read_and_discard_trailer() + # we read everything; close the "file" + self._close_conn() + chunk_left = None + self.chunk_left = chunk_left + return chunk_left + def _readall_chunked(self): assert self.chunked != _UNKNOWN - chunk_left = self.chunk_left value = [] - while True: - if chunk_left is None: - try: - chunk_left = self._read_next_chunk_size() - if chunk_left == 0: - break - except ValueError: - raise IncompleteRead(b''.join(value)) - value.append(self._safe_read(chunk_left)) - - # we read the whole chunk, get another - self._safe_read(2) # toss the CRLF at the end of the chunk - chunk_left = None - - self._read_and_discard_trailer() - - # we read everything; close the "file" - self._close_conn() - - return b''.join(value) + try: + while True: + chunk_left = self._get_chunk_left() + if chunk_left is None: + break + value.append(self._safe_read(chunk_left)) + self.chunk_left = 0 + return b''.join(value) + except IncompleteRead: + raise IncompleteRead(b''.join(value)) def _readinto_chunked(self, b): assert self.chunked != _UNKNOWN - chunk_left = self.chunk_left - total_bytes = 0 mvb = memoryview(b) - while True: - if chunk_left is None: - try: - chunk_left = self._read_next_chunk_size() - if chunk_left == 0: - break - except ValueError: - raise IncompleteRead(bytes(b[0:total_bytes])) - - if len(mvb) < chunk_left: - n = self._safe_readinto(mvb) - self.chunk_left = chunk_left - n - return total_bytes + n - elif len(mvb) == chunk_left: - n = self._safe_readinto(mvb) - self._safe_read(2) # toss the CRLF at the end of the chunk - self.chunk_left = None - return total_bytes + n - else: - temp_mvb = mvb[0:chunk_left] + try: + while True: + chunk_left = self._get_chunk_left() + if chunk_left is None: + return total_bytes + + if len(mvb) <= chunk_left: + n = self._safe_readinto(mvb) + self.chunk_left = chunk_left - n + return total_bytes + n + + temp_mvb = mvb[:chunk_left] n = self._safe_readinto(temp_mvb) mvb = mvb[n:] total_bytes += n + self.chunk_left = 0 - # we read the whole chunk, get another - self._safe_read(2) # toss the CRLF at the end of the chunk - chunk_left = None - - self._read_and_discard_trailer() - - # we read everything; close the "file" - self._close_conn() - - return total_bytes + except IncompleteRead: + raise IncompleteRead(bytes(b[0:total_bytes])) def _safe_read(self, amt): """Read the number of bytes requested, compensating for partial reads. @@ -682,6 +679,73 @@ class HTTPResponse(io.RawIOBase): total_bytes += n return total_bytes + def read1(self, n=-1): + """Read with at most one underlying system call. If at least one + byte is buffered, return that instead. + """ + if self.fp is None or self._method == "HEAD": + return b"" + if self.chunked: + return self._read1_chunked(n) + try: + result = self.fp.read1(n) + except ValueError: + if n >= 0: + raise + # some implementations, like BufferedReader, don't support -1 + # Read an arbitrarily selected largeish chunk. + result = self.fp.read1(16*1024) + if not result and n: + self._close_conn() + return result + + def peek(self, n=-1): + # Having this enables IOBase.readline() to read more than one + # byte at a time + if self.fp is None or self._method == "HEAD": + return b"" + if self.chunked: + return self._peek_chunked(n) + return self.fp.peek(n) + + def readline(self, limit=-1): + if self.fp is None or self._method == "HEAD": + return b"" + if self.chunked: + # Fallback to IOBase readline which uses peek() and read() + return super().readline(limit) + result = self.fp.readline(limit) + if not result and limit: + self._close_conn() + return result + + def _read1_chunked(self, n): + # Strictly speaking, _get_chunk_left() may cause more than one read, + # but that is ok, since that is to satisfy the chunked protocol. + chunk_left = self._get_chunk_left() + if chunk_left is None or n == 0: + return b'' + if not (0 <= n <= chunk_left): + n = chunk_left # if n is negative or larger than chunk_left + read = self.fp.read1(n) + self.chunk_left -= len(read) + if not read: + raise IncompleteRead(b"") + return read + + def _peek_chunked(self, n): + # Strictly speaking, _get_chunk_left() may cause more than one read, + # but that is ok, since that is to satisfy the chunked protocol. + try: + chunk_left = self._get_chunk_left() + except IncompleteRead: + return b'' # peek doesn't worry about protocol + if chunk_left is None: + return b'' # eof + # peek is allowed to return more than requested. Just request the + # entire chunk, and truncate what we get. + return self.fp.peek(chunk_left)[:chunk_left] + def fileno(self): return self.fp.fileno() diff --git a/Lib/idlelib/idlever.py b/Lib/idlelib/idlever.py index 22acb41..d4178b8 100644 --- a/Lib/idlelib/idlever.py +++ b/Lib/idlelib/idlever.py @@ -1 +1 @@ -IDLE_VERSION = "3.4.1" +IDLE_VERSION = "3.5.0a0" diff --git a/Lib/imghdr.py b/Lib/imghdr.py index add2ea8..b267925 100644 --- a/Lib/imghdr.py +++ b/Lib/imghdr.py @@ -110,6 +110,18 @@ def test_bmp(h, f): tests.append(test_bmp) +def test_webp(h, f): + if h.startswith(b'RIFF') and h[8:12] == b'WEBP': + return 'webp' + +tests.append(test_webp) + +def test_exr(h, f): + if h.startswith(b'\x76\x2f\x31\x01'): + return 'exr' + +tests.append(test_exr) + #--------------------# # Small test program # #--------------------# @@ -16,7 +16,7 @@ except ImportError: # Platform doesn't support dynamic loading. load_dynamic = None -from importlib._bootstrap import SourcelessFileLoader, _ERR_MSG, _SpecMethods +from importlib._bootstrap import SourcelessFileLoader, _ERR_MSG, _exec, _load from importlib import machinery from importlib import util @@ -164,11 +164,10 @@ class _LoadSourceCompatibility(_HackedGetData, machinery.SourceFileLoader): def load_source(name, pathname, file=None): loader = _LoadSourceCompatibility(name, pathname, file) spec = util.spec_from_file_location(name, pathname, loader=loader) - methods = _SpecMethods(spec) if name in sys.modules: - module = methods.exec(sys.modules[name]) + module = _exec(spec, sys.modules[name]) else: - module = methods.load() + module = _load(spec) # To allow reloading to potentially work, use a non-hacked loader which # won't rely on a now-closed file object. module.__loader__ = machinery.SourceFileLoader(name, pathname) @@ -185,11 +184,10 @@ def load_compiled(name, pathname, file=None): """**DEPRECATED**""" loader = _LoadCompiledCompatibility(name, pathname, file) spec = util.spec_from_file_location(name, pathname, loader=loader) - methods = _SpecMethods(spec) if name in sys.modules: - module = methods.exec(sys.modules[name]) + module = _exec(spec, sys.modules[name]) else: - module = methods.load() + module = _load(spec) # To allow reloading to potentially work, use a non-hacked loader which # won't rely on a now-closed file object. module.__loader__ = SourcelessFileLoader(name, pathname) @@ -210,11 +208,10 @@ def load_package(name, path): raise ValueError('{!r} is not a package'.format(path)) spec = util.spec_from_file_location(name, path, submodule_search_locations=[]) - methods = _SpecMethods(spec) if name in sys.modules: - return methods.exec(sys.modules[name]) + return _exec(spec, sys.modules[name]) else: - return methods.load() + return _load(spec) def load_module(name, file, filename, details): diff --git a/Lib/importlib/__init__.py b/Lib/importlib/__init__.py index 1bc9947..e0fe466 100644 --- a/Lib/importlib/__init__.py +++ b/Lib/importlib/__init__.py @@ -145,8 +145,7 @@ def reload(module): pkgpath = None target = module spec = module.__spec__ = _bootstrap._find_spec(name, pkgpath, target) - methods = _bootstrap._SpecMethods(spec) - methods.exec(module) + _bootstrap._exec(spec, module) # The module may have replaced itself in sys.modules! return sys.modules[name] finally: diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index b8836c1..c4ee41a 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -9,7 +9,7 @@ work. One should use importlib as the public-facing version of this module. # # IMPORTANT: Whenever making changes to this module, be sure to run # a top-level make in order to get the frozen version of the module -# update. Not doing so will result in the Makefile to fail for +# updated. Not doing so will result in the Makefile to fail for # all others who don't have a ./python around to freeze the module # in the early stages of compilation. # @@ -419,12 +419,13 @@ def _call_with_frames_removed(f, *args, **kwds): # Python 3.4a4 3290 (changes to __qualname__ computation) # Python 3.4a4 3300 (more changes to __qualname__ computation) # Python 3.4rc2 3310 (alter __qualname__ computation) +# Python 3.5a0 3320 (matrix multiplication operator) # # MAGIC must change whenever the bytecode emitted by the compiler may no # longer be understood by older implementations of the eval loop (usually # due to the addition of new opcodes). -MAGIC_NUMBER = (3310).to_bytes(2, 'little') + b'\r\n' +MAGIC_NUMBER = (3320).to_bytes(2, 'little') + b'\r\n' _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c _PYCACHE = '__pycache__' @@ -580,6 +581,7 @@ def _find_module_shim(self, fullname): return loader +# Typically used by loader classes as a method replacement. def _load_module_shim(self, fullname): """Load the specified module into sys.modules and return it. @@ -587,13 +589,12 @@ def _load_module_shim(self, fullname): """ spec = spec_from_loader(fullname, self) - methods = _SpecMethods(spec) if fullname in sys.modules: module = sys.modules[fullname] - methods.exec(module) + _exec(spec, module) return sys.modules[fullname] else: - return methods.load() + return _load(spec) def _validate_bytecode_header(data, source_stats=None, name=None, path=None): @@ -704,7 +705,7 @@ def _module_repr(module): pass else: if spec is not None: - return _SpecMethods(spec).module_repr() + return _module_repr_from_spec(spec) # We could use module.__class__.__name__ instead of 'module' in the # various repr permutations. @@ -990,234 +991,182 @@ def _spec_from_module(module, loader=None, origin=None): return spec -class _SpecMethods: - - """Convenience wrapper around spec objects to provide spec-specific - methods.""" - - # The various spec_from_* functions could be made factory methods here. - - def __init__(self, spec): - self.spec = spec - - def module_repr(self): - """Return the repr to use for the module.""" - # We mostly replicate _module_repr() using the spec attributes. - spec = self.spec - name = '?' if spec.name is None else spec.name - if spec.origin is None: - if spec.loader is None: - return '<module {!r}>'.format(name) - else: - return '<module {!r} ({!r})>'.format(name, spec.loader) - else: - if spec.has_location: - return '<module {!r} from {!r}>'.format(name, spec.origin) - else: - return '<module {!r} ({})>'.format(spec.name, spec.origin) - - def init_module_attrs(self, module, *, _override=False, _force_name=True): - """Set the module's attributes. - - All missing import-related module attributes will be set. Here - is how the spec attributes map onto the module: - - spec.name -> module.__name__ - spec.loader -> module.__loader__ - spec.parent -> module.__package__ - spec -> module.__spec__ - - Optional: - spec.origin -> module.__file__ (if spec.set_fileattr is true) - spec.cached -> module.__cached__ (if __file__ also set) - spec.submodule_search_locations -> module.__path__ (if set) - - """ - spec = self.spec - - # The passed in module may be not support attribute assignment, - # in which case we simply don't set the attributes. - - # __name__ - if (_override or _force_name or - getattr(module, '__name__', None) is None): - try: - module.__name__ = spec.name - except AttributeError: - pass - - # __loader__ - if _override or getattr(module, '__loader__', None) is None: - loader = spec.loader - if loader is None: - # A backward compatibility hack. - if spec.submodule_search_locations is not None: - loader = _NamespaceLoader.__new__(_NamespaceLoader) - loader._path = spec.submodule_search_locations +def _init_module_attrs(spec, module, *, override=False): + # The passed-in module may be not support attribute assignment, + # in which case we simply don't set the attributes. + # __name__ + if (override or getattr(module, '__name__', None) is None): + try: + module.__name__ = spec.name + except AttributeError: + pass + # __loader__ + if override or getattr(module, '__loader__', None) is None: + loader = spec.loader + if loader is None: + # A backward compatibility hack. + if spec.submodule_search_locations is not None: + loader = _NamespaceLoader.__new__(_NamespaceLoader) + loader._path = spec.submodule_search_locations + try: + module.__loader__ = loader + except AttributeError: + pass + # __package__ + if override or getattr(module, '__package__', None) is None: + try: + module.__package__ = spec.parent + except AttributeError: + pass + # __spec__ + try: + module.__spec__ = spec + except AttributeError: + pass + # __path__ + if override or getattr(module, '__path__', None) is None: + if spec.submodule_search_locations is not None: try: - module.__loader__ = loader + module.__path__ = spec.submodule_search_locations except AttributeError: pass - - # __package__ - if _override or getattr(module, '__package__', None) is None: + # __file__/__cached__ + if spec.has_location: + if override or getattr(module, '__file__', None) is None: try: - module.__package__ = spec.parent + module.__file__ = spec.origin except AttributeError: pass - # __spec__ - try: - module.__spec__ = spec - except AttributeError: - pass - - # __path__ - if _override or getattr(module, '__path__', None) is None: - if spec.submodule_search_locations is not None: + if override or getattr(module, '__cached__', None) is None: + if spec.cached is not None: try: - module.__path__ = spec.submodule_search_locations - except AttributeError: - pass - - if spec.has_location: - # __file__ - if _override or getattr(module, '__file__', None) is None: - try: - module.__file__ = spec.origin + module.__cached__ = spec.cached except AttributeError: pass + return module - # __cached__ - if _override or getattr(module, '__cached__', None) is None: - if spec.cached is not None: - try: - module.__cached__ = spec.cached - except AttributeError: - pass - def create(self): - """Return a new module to be loaded. +def module_from_spec(spec): + """Create a module based on the provided spec.""" + # Typically loaders will not implement create_module(). + module = None + if hasattr(spec.loader, 'create_module'): + # If create_module() returns `None` then it means default + # module creation should be used. + module = spec.loader.create_module(spec) + if module is None: + module = _new_module(spec.name) + _init_module_attrs(spec, module) + return module - The import-related module attributes are also set with the - appropriate values from the spec. - """ - spec = self.spec - # Typically loaders will not implement create_module(). - if hasattr(spec.loader, 'create_module'): - # If create_module() returns `None` it means the default - # module creation should be used. - module = spec.loader.create_module(spec) +def _module_repr_from_spec(spec): + """Return the repr to use for the module.""" + # We mostly replicate _module_repr() using the spec attributes. + name = '?' if spec.name is None else spec.name + if spec.origin is None: + if spec.loader is None: + return '<module {!r}>'.format(name) else: - module = None - if module is None: - # This must be done before open() is ever called as the 'io' - # module implicitly imports 'locale' and would otherwise - # trigger an infinite loop. - module = _new_module(spec.name) - self.init_module_attrs(module) - return module - - def _exec(self, module): - """Do everything necessary to execute the module. - - The namespace of `module` is used as the target of execution. - This method uses the loader's `exec_module()` method. + return '<module {!r} ({!r})>'.format(name, spec.loader) + else: + if spec.has_location: + return '<module {!r} from {!r}>'.format(name, spec.origin) + else: + return '<module {!r} ({})>'.format(spec.name, spec.origin) - """ - self.spec.loader.exec_module(module) - # Used by importlib.reload() and _load_module_shim(). - def exec(self, module): - """Execute the spec in an existing module's namespace.""" - name = self.spec.name - _imp.acquire_lock() - with _ModuleLockManager(name): - if sys.modules.get(name) is not module: - msg = 'module {!r} not in sys.modules'.format(name) - raise ImportError(msg, name=name) - if self.spec.loader is None: - if self.spec.submodule_search_locations is None: - raise ImportError('missing loader', name=self.spec.name) - # namespace package - self.init_module_attrs(module, _override=True) - return module - self.init_module_attrs(module, _override=True) - if not hasattr(self.spec.loader, 'exec_module'): - # (issue19713) Once BuiltinImporter and ExtensionFileLoader - # have exec_module() implemented, we can add a deprecation - # warning here. - self.spec.loader.load_module(name) - else: - self._exec(module) - return sys.modules[name] - - def _load_backward_compatible(self): - # (issue19713) Once BuiltinImporter and ExtensionFileLoader - # have exec_module() implemented, we can add a deprecation - # warning here. - spec = self.spec - spec.loader.load_module(spec.name) - # The module must be in sys.modules at this point! - module = sys.modules[spec.name] - if getattr(module, '__loader__', None) is None: - try: - module.__loader__ = spec.loader - except AttributeError: - pass - if getattr(module, '__package__', None) is None: - try: - # Since module.__path__ may not line up with - # spec.submodule_search_paths, we can't necessarily rely - # on spec.parent here. - module.__package__ = module.__name__ - if not hasattr(module, '__path__'): - module.__package__ = spec.name.rpartition('.')[0] - except AttributeError: - pass - if getattr(module, '__spec__', None) is None: - try: - module.__spec__ = spec - except AttributeError: - pass - return module +# Used by importlib.reload() and _load_module_shim(). +def _exec(spec, module): + """Execute the spec in an existing module's namespace.""" + name = spec.name + _imp.acquire_lock() + with _ModuleLockManager(name): + if sys.modules.get(name) is not module: + msg = 'module {!r} not in sys.modules'.format(name) + raise ImportError(msg, name=name) + if spec.loader is None: + if spec.submodule_search_locations is None: + raise ImportError('missing loader', name=spec.name) + # namespace package + _init_module_attrs(spec, module, override=True) + return module + _init_module_attrs(spec, module, override=True) + if not hasattr(spec.loader, 'exec_module'): + # (issue19713) Once BuiltinImporter and ExtensionFileLoader + # have exec_module() implemented, we can add a deprecation + # warning here. + spec.loader.load_module(name) + else: + spec.loader.exec_module(module) + return sys.modules[name] + + +def _load_backward_compatible(spec): + # (issue19713) Once BuiltinImporter and ExtensionFileLoader + # have exec_module() implemented, we can add a deprecation + # warning here. + spec.loader.load_module(spec.name) + # The module must be in sys.modules at this point! + module = sys.modules[spec.name] + if getattr(module, '__loader__', None) is None: + try: + module.__loader__ = spec.loader + except AttributeError: + pass + if getattr(module, '__package__', None) is None: + try: + # Since module.__path__ may not line up with + # spec.submodule_search_paths, we can't necessarily rely + # on spec.parent here. + module.__package__ = module.__name__ + if not hasattr(module, '__path__'): + module.__package__ = spec.name.rpartition('.')[0] + except AttributeError: + pass + if getattr(module, '__spec__', None) is None: + try: + module.__spec__ = spec + except AttributeError: + pass + return module - def _load_unlocked(self): - # A helper for direct use by the import system. - if self.spec.loader is not None: - # not a namespace package - if not hasattr(self.spec.loader, 'exec_module'): - return self._load_backward_compatible() - - module = self.create() - with _installed_safely(module): - if self.spec.loader is None: - if self.spec.submodule_search_locations is None: - raise ImportError('missing loader', name=self.spec.name) - # A namespace package so do nothing. - else: - self._exec(module) +def _load_unlocked(spec): + # A helper for direct use by the import system. + if spec.loader is not None: + # not a namespace package + if not hasattr(spec.loader, 'exec_module'): + return _load_backward_compatible(spec) + + module = module_from_spec(spec) + with _installed_safely(module): + if spec.loader is None: + if spec.submodule_search_locations is None: + raise ImportError('missing loader', name=spec.name) + # A namespace package so do nothing. + else: + spec.loader.exec_module(module) - # We don't ensure that the import-related module attributes get - # set in the sys.modules replacement case. Such modules are on - # their own. - return sys.modules[self.spec.name] + # We don't ensure that the import-related module attributes get + # set in the sys.modules replacement case. Such modules are on + # their own. + return sys.modules[spec.name] - # A method used during testing of _load_unlocked() and by - # _load_module_shim(). - def load(self): - """Return a new module object, loaded by the spec's loader. +# A method used during testing of _load_unlocked() and by +# _load_module_shim(). +def _load(spec): + """Return a new module object, loaded by the spec's loader. - The module is not added to its parent. + The module is not added to its parent. - If a module is already in sys.modules, that existing module gets - clobbered. + If a module is already in sys.modules, that existing module gets + clobbered. - """ - _imp.acquire_lock() - with _ModuleLockManager(self.spec.name): - return self._load_unlocked() + """ + _imp.acquire_lock() + with _ModuleLockManager(spec.name): + return _load_unlocked(spec) def _fix_up_module(ns, name, pathname, cpathname=None): @@ -1799,7 +1748,7 @@ class _NamespacePath: self._path.append(item) -# We use this exclusively in init_module_attrs() for backward-compatibility. +# We use this exclusively in module_from_spec() for backward-compatibility. class _NamespaceLoader: def __init__(self, name, path, path_finder): self._path = _NamespacePath(name, path, path_finder) @@ -2223,7 +2172,7 @@ def _find_and_load_unlocked(name, import_): if spec is None: raise ImportError(_ERR_MSG.format(name), name=name) else: - module = _SpecMethods(spec)._load_unlocked() + module = _load_unlocked(spec) if parent: # Set the module as an attribute on its parent. parent_module = sys.modules[parent] @@ -2358,8 +2307,7 @@ def _builtin_from_name(name): spec = BuiltinImporter.find_spec(name) if spec is None: raise ImportError('no built-in module named ' + name) - methods = _SpecMethods(spec) - return methods._load_unlocked() + return _load_unlocked(spec) def _setup(sys_module, _imp_module): @@ -2390,8 +2338,7 @@ def _setup(sys_module, _imp_module): else: continue spec = _spec_from_module(module, loader) - methods = _SpecMethods(spec) - methods.init_module_attrs(module) + _init_module_attrs(spec, module) # Directly load built-in modules needed during bootstrap. self_module = sys.modules[__name__] diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py index 558abd3..6b6a602 100644 --- a/Lib/importlib/abc.py +++ b/Lib/importlib/abc.py @@ -126,7 +126,7 @@ class Loader(metaclass=abc.ABCMeta): create_module() is optional. """ - # By default, defer to _SpecMethods.create() for the new module. + # By default, defer to default semantics for the new module. return None # We don't define exec_module() here since that would break @@ -217,7 +217,8 @@ class InspectLoader(Loader): """ raise ImportError - def source_to_code(self, data, path='<string>'): + @staticmethod + def source_to_code(data, path='<string>'): """Compile 'data' into a code object. The 'data' argument can be anything that compile() can handle. The'path' diff --git a/Lib/importlib/util.py b/Lib/importlib/util.py index 6d73b1d..2424144 100644 --- a/Lib/importlib/util.py +++ b/Lib/importlib/util.py @@ -1,8 +1,9 @@ """Utility code for constructing importers, etc.""" - +from . import abc from ._bootstrap import MAGIC_NUMBER from ._bootstrap import cache_from_source from ._bootstrap import decode_source +from ._bootstrap import module_from_spec from ._bootstrap import source_from_cache from ._bootstrap import spec_from_loader from ._bootstrap import spec_from_file_location @@ -12,6 +13,7 @@ from ._bootstrap import _find_spec from contextlib import contextmanager import functools import sys +import types import warnings @@ -200,3 +202,94 @@ def module_for_loader(fxn): return fxn(self, module, *args, **kwargs) return module_for_loader_wrapper + + +class _Module(types.ModuleType): + + """A subclass of the module type to allow __class__ manipulation.""" + + +class _LazyModule(types.ModuleType): + + """A subclass of the module type which triggers loading upon attribute access.""" + + def __getattribute__(self, attr): + """Trigger the load of the module and return the attribute.""" + # All module metadata must be garnered from __spec__ in order to avoid + # using mutated values. + # Stop triggering this method. + self.__class__ = _Module + # Get the original name to make sure no object substitution occurred + # in sys.modules. + original_name = self.__spec__.name + # Figure out exactly what attributes were mutated between the creation + # of the module and now. + attrs_then = self.__spec__.loader_state + attrs_now = self.__dict__ + attrs_updated = {} + for key, value in attrs_now.items(): + # Code that set the attribute may have kept a reference to the + # assigned object, making identity more important than equality. + if key not in attrs_then: + attrs_updated[key] = value + elif id(attrs_now[key]) != id(attrs_then[key]): + attrs_updated[key] = value + self.__spec__.loader.exec_module(self) + # If exec_module() was used directly there is no guarantee the module + # object was put into sys.modules. + if original_name in sys.modules: + if id(self) != id(sys.modules[original_name]): + msg = ('module object for {!r} substituted in sys.modules ' + 'during a lazy load') + raise ValueError(msg.format(original_name)) + # Update after loading since that's what would happen in an eager + # loading situation. + self.__dict__.update(attrs_updated) + return getattr(self, attr) + + def __delattr__(self, attr): + """Trigger the load and then perform the deletion.""" + # To trigger the load and raise an exception if the attribute + # doesn't exist. + self.__getattribute__(attr) + delattr(self, attr) + + +class LazyLoader(abc.Loader): + + """A loader that creates a module which defers loading until attribute access.""" + + @staticmethod + def __check_eager_loader(loader): + if not hasattr(loader, 'exec_module'): + raise TypeError('loader must define exec_module()') + elif hasattr(loader.__class__, 'create_module'): + if abc.Loader.create_module != loader.__class__.create_module: + # Only care if create_module() is overridden in a subclass of + # importlib.abc.Loader. + raise TypeError('loader cannot define create_module()') + + @classmethod + def factory(cls, loader): + """Construct a callable which returns the eager loader made lazy.""" + cls.__check_eager_loader(loader) + return lambda *args, **kwargs: cls(loader(*args, **kwargs)) + + def __init__(self, loader): + self.__check_eager_loader(loader) + self.loader = loader + + def create_module(self, spec): + """Create a module which can have its __class__ manipulated.""" + return _Module(spec.name) + + def exec_module(self, module): + """Make the module load lazily.""" + module.__spec__.loader = self.loader + module.__loader__ = self.loader + # Don't need to worry about deep-copying as trying to set an attribute + # on an object would have triggered the load, + # e.g. ``module.__spec__.loader = None`` would trigger a load from + # trying to access module.__spec__. + module.__spec__.loader_state = module.__dict__.copy() + module.__class__ = _LazyModule diff --git a/Lib/inspect.py b/Lib/inspect.py index f6e1b47..f6b5bad 100644 --- a/Lib/inspect.py +++ b/Lib/inspect.py @@ -17,7 +17,7 @@ Here are some of the useful functions provided by this module: getclasstree() - arrange classes so as to represent their hierarchy getargspec(), getargvalues(), getcallargs() - get info about function arguments - getfullargspec() - same, with support for Python-3000 features + getfullargspec() - same, with support for Python 3 features formatargspec(), formatargvalues() - format an argument spec getouterframes(), getinnerframes() - get info about frames currentframe() - get the current stack frame @@ -32,6 +32,7 @@ __author__ = ('Ka-Ping Yee <ping@lfw.org>', 'Yury Selivanov <yselivanov@sprymix.com>') import ast +import enum import importlib.machinery import itertools import linecache @@ -913,13 +914,12 @@ ArgSpec = namedtuple('ArgSpec', 'args varargs keywords defaults') def getargspec(func): """Get the names and default values of a function's arguments. - A tuple of four things is returned: (args, varargs, varkw, defaults). - 'args' is a list of the argument names. - 'args' will include keyword-only argument names. - 'varargs' and 'varkw' are the names of the * and ** arguments or None. + A tuple of four things is returned: (args, varargs, keywords, defaults). + 'args' is a list of the argument names, including keyword-only argument names. + 'varargs' and 'keywords' are the names of the * and ** arguments or None. 'defaults' is an n-tuple of the default values of the last n arguments. - Use the getfullargspec() API for Python-3000 code, as annotations + Use the getfullargspec() API for Python 3 code, as annotations and keyword arguments are supported. getargspec() will raise ValueError if the func has either annotations or keyword arguments. """ @@ -966,9 +966,10 @@ def getfullargspec(func): # getfullargspec() historically ignored __wrapped__ attributes, # so we ensure that remains the case in 3.3+ - sig = _signature_internal(func, - follow_wrapper_chains=False, - skip_bound_arg=False) + sig = _signature_from_callable(func, + follow_wrapper_chains=False, + skip_bound_arg=False, + sigcls=Signature) except Exception as ex: # Most of the times 'signature' will raise ValueError. # But, it can also raise AttributeError, and, maybe something @@ -1495,6 +1496,10 @@ _NonUserDefinedCallables = (_WrapperDescriptor, def _signature_get_user_defined_method(cls, method_name): + """Private helper. Checks if ``cls`` has an attribute + named ``method_name`` and returns it only if it is a + pure python function. + """ try: meth = getattr(cls, method_name) except AttributeError: @@ -1507,9 +1512,10 @@ def _signature_get_user_defined_method(cls, method_name): def _signature_get_partial(wrapped_sig, partial, extra_args=()): - # Internal helper to calculate how 'wrapped_sig' signature will - # look like after applying a 'functools.partial' object (or alike) - # on it. + """Private helper to calculate how 'wrapped_sig' signature will + look like after applying a 'functools.partial' object (or alike) + on it. + """ old_params = wrapped_sig.parameters new_params = OrderedDict(old_params.items()) @@ -1582,8 +1588,9 @@ def _signature_get_partial(wrapped_sig, partial, extra_args=()): def _signature_bound_method(sig): - # Internal helper to transform signatures for unbound - # functions to bound methods + """Private helper to transform signatures for unbound + functions to bound methods. + """ params = tuple(sig.parameters.values()) @@ -1607,8 +1614,9 @@ def _signature_bound_method(sig): def _signature_is_builtin(obj): - # Internal helper to test if `obj` is a callable that might - # support Argument Clinic's __text_signature__ protocol. + """Private helper to test if `obj` is a callable that might + support Argument Clinic's __text_signature__ protocol. + """ return (isbuiltin(obj) or ismethoddescriptor(obj) or isinstance(obj, _NonUserDefinedCallables) or @@ -1618,10 +1626,11 @@ def _signature_is_builtin(obj): def _signature_is_functionlike(obj): - # Internal helper to test if `obj` is a duck type of FunctionType. - # A good example of such objects are functions compiled with - # Cython, which have all attributes that a pure Python function - # would have, but have their code statically compiled. + """Private helper to test if `obj` is a duck type of FunctionType. + A good example of such objects are functions compiled with + Cython, which have all attributes that a pure Python function + would have, but have their code statically compiled. + """ if not callable(obj) or isclass(obj): # All function-like objects are obviously callables, @@ -1642,11 +1651,12 @@ def _signature_is_functionlike(obj): def _signature_get_bound_param(spec): - # Internal helper to get first parameter name from a - # __text_signature__ of a builtin method, which should - # be in the following format: '($param1, ...)'. - # Assumptions are that the first argument won't have - # a default value or an annotation. + """ Private helper to get first parameter name from a + __text_signature__ of a builtin method, which should + be in the following format: '($param1, ...)'. + Assumptions are that the first argument won't have + a default value or an annotation. + """ assert spec.startswith('($') @@ -1665,7 +1675,9 @@ def _signature_get_bound_param(spec): def _signature_strip_non_python_syntax(signature): """ - Takes a signature in Argument Clinic's extended signature format. + Private helper function. Takes a signature in Argument Clinic's + extended signature format. + Returns a tuple of three things: * that signature re-rendered in standard Python syntax, * the index of the "self" parameter (generally 0), or None if @@ -1734,8 +1746,10 @@ def _signature_strip_non_python_syntax(signature): def _signature_fromstr(cls, obj, s, skip_bound_arg=True): - # Internal helper to parse content of '__text_signature__' - # and return a Signature based on it + """Private helper to parse content of '__text_signature__' + and return a Signature based on it. + """ + Parameter = cls._parameter_cls clean_signature, self_parameter, last_positional_only = \ @@ -1873,8 +1887,10 @@ def _signature_fromstr(cls, obj, s, skip_bound_arg=True): def _signature_from_builtin(cls, func, skip_bound_arg=True): - # Internal helper function to get signature for - # builtin callables + """Private helper function to get signature for + builtin callables. + """ + if not _signature_is_builtin(func): raise TypeError("{!r} is not a Python builtin " "function".format(func)) @@ -1886,7 +1902,14 @@ def _signature_from_builtin(cls, func, skip_bound_arg=True): return _signature_fromstr(cls, func, s, skip_bound_arg) -def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): +def _signature_from_callable(obj, *, + follow_wrapper_chains=True, + skip_bound_arg=True, + sigcls): + + """Private helper function to get signature for arbitrary + callable objects. + """ if not callable(obj): raise TypeError('{!r} is not a callable object'.format(obj)) @@ -1894,9 +1917,12 @@ def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): if isinstance(obj, types.MethodType): # In this case we skip the first parameter of the underlying # function (usually `self` or `cls`). - sig = _signature_internal(obj.__func__, - follow_wrapper_chains, - skip_bound_arg) + sig = _signature_from_callable( + obj.__func__, + follow_wrapper_chains=follow_wrapper_chains, + skip_bound_arg=skip_bound_arg, + sigcls=sigcls) + if skip_bound_arg: return _signature_bound_method(sig) else: @@ -1931,9 +1957,12 @@ def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): # (usually `self`, or `cls`) will not be passed # automatically (as for boundmethods) - wrapped_sig = _signature_internal(partialmethod.func, - follow_wrapper_chains, - skip_bound_arg) + wrapped_sig = _signature_from_callable( + partialmethod.func, + follow_wrapper_chains=follow_wrapper_chains, + skip_bound_arg=skip_bound_arg, + sigcls=sigcls) + sig = _signature_get_partial(wrapped_sig, partialmethod, (None,)) first_wrapped_param = tuple(wrapped_sig.parameters.values())[0] @@ -1944,16 +1973,18 @@ def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): if isfunction(obj) or _signature_is_functionlike(obj): # If it's a pure Python function, or an object that is duck type # of a Python function (Cython functions, for instance), then: - return Signature.from_function(obj) + return sigcls.from_function(obj) if _signature_is_builtin(obj): - return _signature_from_builtin(Signature, obj, + return _signature_from_builtin(sigcls, obj, skip_bound_arg=skip_bound_arg) if isinstance(obj, functools.partial): - wrapped_sig = _signature_internal(obj.func, - follow_wrapper_chains, - skip_bound_arg) + wrapped_sig = _signature_from_callable( + obj.func, + follow_wrapper_chains=follow_wrapper_chains, + skip_bound_arg=skip_bound_arg, + sigcls=sigcls) return _signature_get_partial(wrapped_sig, obj) sig = None @@ -1964,23 +1995,29 @@ def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): # in its metaclass call = _signature_get_user_defined_method(type(obj), '__call__') if call is not None: - sig = _signature_internal(call, - follow_wrapper_chains, - skip_bound_arg) + sig = _signature_from_callable( + call, + follow_wrapper_chains=follow_wrapper_chains, + skip_bound_arg=skip_bound_arg, + sigcls=sigcls) else: # Now we check if the 'obj' class has a '__new__' method new = _signature_get_user_defined_method(obj, '__new__') if new is not None: - sig = _signature_internal(new, - follow_wrapper_chains, - skip_bound_arg) + sig = _signature_from_callable( + new, + follow_wrapper_chains=follow_wrapper_chains, + skip_bound_arg=skip_bound_arg, + sigcls=sigcls) else: # Finally, we should have at least __init__ implemented init = _signature_get_user_defined_method(obj, '__init__') if init is not None: - sig = _signature_internal(init, - follow_wrapper_chains, - skip_bound_arg) + sig = _signature_from_callable( + init, + follow_wrapper_chains=follow_wrapper_chains, + skip_bound_arg=skip_bound_arg, + sigcls=sigcls) if sig is None: # At this point we know, that `obj` is a class, with no user- @@ -2002,7 +2039,7 @@ def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): if text_sig: # If 'obj' class has a __text_signature__ attribute: # return a signature based on it - return _signature_fromstr(Signature, obj, text_sig) + return _signature_fromstr(sigcls, obj, text_sig) # No '__text_signature__' was found for the 'obj' class. # Last option is to check if its '__init__' is @@ -2022,9 +2059,11 @@ def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): call = _signature_get_user_defined_method(type(obj), '__call__') if call is not None: try: - sig = _signature_internal(call, - follow_wrapper_chains, - skip_bound_arg) + sig = _signature_from_callable( + call, + follow_wrapper_chains=follow_wrapper_chains, + skip_bound_arg=skip_bound_arg, + sigcls=sigcls) except ValueError as ex: msg = 'no signature found for {!r}'.format(obj) raise ValueError(msg) from ex @@ -2044,41 +2083,35 @@ def _signature_internal(obj, follow_wrapper_chains=True, skip_bound_arg=True): raise ValueError('callable {!r} is not supported by signature'.format(obj)) -def signature(obj): - '''Get a signature object for the passed callable.''' - return _signature_internal(obj) - class _void: - '''A private marker - used in Parameter & Signature''' + """A private marker - used in Parameter & Signature.""" class _empty: - pass + """Marker object for Signature.empty and Parameter.empty.""" -class _ParameterKind(int): - def __new__(self, *args, name): - obj = int.__new__(self, *args) - obj._name = name - return obj +class _ParameterKind(enum.IntEnum): + POSITIONAL_ONLY = 0 + POSITIONAL_OR_KEYWORD = 1 + VAR_POSITIONAL = 2 + KEYWORD_ONLY = 3 + VAR_KEYWORD = 4 def __str__(self): - return self._name - - def __repr__(self): - return '<_ParameterKind: {!r}>'.format(self._name) + return self._name_ -_POSITIONAL_ONLY = _ParameterKind(0, name='POSITIONAL_ONLY') -_POSITIONAL_OR_KEYWORD = _ParameterKind(1, name='POSITIONAL_OR_KEYWORD') -_VAR_POSITIONAL = _ParameterKind(2, name='VAR_POSITIONAL') -_KEYWORD_ONLY = _ParameterKind(3, name='KEYWORD_ONLY') -_VAR_KEYWORD = _ParameterKind(4, name='VAR_KEYWORD') +_POSITIONAL_ONLY = _ParameterKind.POSITIONAL_ONLY +_POSITIONAL_OR_KEYWORD = _ParameterKind.POSITIONAL_OR_KEYWORD +_VAR_POSITIONAL = _ParameterKind.VAR_POSITIONAL +_KEYWORD_ONLY = _ParameterKind.KEYWORD_ONLY +_VAR_KEYWORD = _ParameterKind.VAR_KEYWORD class Parameter: - '''Represents a parameter in a function signature. + """Represents a parameter in a function signature. Has the following public attributes: @@ -2097,7 +2130,7 @@ class Parameter: Possible values: `Parameter.POSITIONAL_ONLY`, `Parameter.POSITIONAL_OR_KEYWORD`, `Parameter.VAR_POSITIONAL`, `Parameter.KEYWORD_ONLY`, `Parameter.VAR_KEYWORD`. - ''' + """ __slots__ = ('_name', '_kind', '_default', '_annotation') @@ -2134,6 +2167,16 @@ class Parameter: self._name = name + def __reduce__(self): + return (type(self), + (self._name, self._kind), + {'_default': self._default, + '_annotation': self._annotation}) + + def __setstate__(self, state): + self._default = state['_default'] + self._annotation = state['_annotation'] + @property def name(self): return self._name @@ -2152,7 +2195,7 @@ class Parameter: def replace(self, *, name=_void, kind=_void, annotation=_void, default=_void): - '''Creates a customized copy of the Parameter.''' + """Creates a customized copy of the Parameter.""" if name is _void: name = self._name @@ -2188,8 +2231,18 @@ class Parameter: return formatted def __repr__(self): - return '<{} at {:#x} {!r}>'.format(self.__class__.__name__, - id(self), self.name) + return '<{} at {:#x} "{}">'.format(self.__class__.__name__, + id(self), self) + + def __hash__(self): + hash_tuple = (self.name, int(self.kind)) + + if self._annotation is not _empty: + hash_tuple += (self._annotation,) + if self._default is not _empty: + hash_tuple += (self._default,) + + return hash(hash_tuple) def __eq__(self, other): return (issubclass(other.__class__, Parameter) and @@ -2203,7 +2256,7 @@ class Parameter: class BoundArguments: - '''Result of `Signature.bind` call. Holds the mapping of arguments + """Result of `Signature.bind` call. Holds the mapping of arguments to the function's parameters. Has the following public attributes: @@ -2217,7 +2270,7 @@ class BoundArguments: Tuple of positional arguments values. * kwargs : dict Dict of keyword arguments values. - ''' + """ def __init__(self, signature, arguments): self.arguments = arguments @@ -2290,7 +2343,7 @@ class BoundArguments: class Signature: - '''A Signature object represents the overall signature of a function. + """A Signature object represents the overall signature of a function. It stores a Parameter object for each parameter accepted by the function, as well as information specific to the function itself. @@ -2310,7 +2363,7 @@ class Signature: * bind_partial(*args, **kwargs) -> BoundArguments Creates a partial mapping from positional and keyword arguments to parameters (simulating 'functools.partial' behavior.) - ''' + """ __slots__ = ('_return_annotation', '_parameters') @@ -2321,9 +2374,9 @@ class Signature: def __init__(self, parameters=None, *, return_annotation=_empty, __validate_parameters__=True): - '''Constructs Signature from the given list of Parameter + """Constructs Signature from the given list of Parameter objects and 'return_annotation'. All arguments are optional. - ''' + """ if parameters is None: params = OrderedDict() @@ -2372,7 +2425,7 @@ class Signature: @classmethod def from_function(cls, func): - '''Constructs Signature for the given python function''' + """Constructs Signature for the given python function.""" is_duck_function = False if not isfunction(func): @@ -2453,8 +2506,14 @@ class Signature: @classmethod def from_builtin(cls, func): + """Constructs Signature for the given builtin function.""" return _signature_from_builtin(cls, func) + @classmethod + def from_callable(cls, obj): + """Constructs Signature for the given callable object.""" + return _signature_from_callable(obj, sigcls=cls) + @property def parameters(self): return self._parameters @@ -2464,10 +2523,10 @@ class Signature: return self._return_annotation def replace(self, *, parameters=_void, return_annotation=_void): - '''Creates a customized copy of the Signature. + """Creates a customized copy of the Signature. Pass 'parameters' and/or 'return_annotation' arguments to override them in the new copy. - ''' + """ if parameters is _void: parameters = self.parameters.values() @@ -2478,6 +2537,12 @@ class Signature: return type(self)(parameters, return_annotation=return_annotation) + def __hash__(self): + hash_tuple = tuple(self.parameters.values()) + if self._return_annotation is not _empty: + hash_tuple += (self._return_annotation,) + return hash(hash_tuple) + def __eq__(self, other): if (not issubclass(type(other), Signature) or self.return_annotation != other.return_annotation or @@ -2512,7 +2577,7 @@ class Signature: return not self.__eq__(other) def _bind(self, args, kwargs, *, partial=False): - '''Private method. Don't use directly.''' + """Private method. Don't use directly.""" arguments = OrderedDict() @@ -2639,19 +2704,31 @@ class Signature: return self._bound_arguments_cls(self, arguments) def bind(*args, **kwargs): - '''Get a BoundArguments object, that maps the passed `args` + """Get a BoundArguments object, that maps the passed `args` and `kwargs` to the function's signature. Raises `TypeError` if the passed arguments can not be bound. - ''' + """ return args[0]._bind(args[1:], kwargs) def bind_partial(*args, **kwargs): - '''Get a BoundArguments object, that partially maps the + """Get a BoundArguments object, that partially maps the passed `args` and `kwargs` to the function's signature. Raises `TypeError` if the passed arguments can not be bound. - ''' + """ return args[0]._bind(args[1:], kwargs, partial=True) + def __reduce__(self): + return (type(self), + (tuple(self._parameters.values()),), + {'_return_annotation': self._return_annotation}) + + def __setstate__(self, state): + self._return_annotation = state['_return_annotation'] + + def __repr__(self): + return '<{} at {:#x} "{}">'.format(self.__class__.__name__, + id(self), self) + def __str__(self): result = [] render_pos_only_separator = False @@ -2697,6 +2774,12 @@ class Signature: return rendered + +def signature(obj): + """Get a signature object for the passed callable.""" + return Signature.from_callable(obj) + + def _main(): """ Logic for inspecting an object given at command line """ import argparse diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py index 54df39a..bf2de2d 100644 --- a/Lib/ipaddress.py +++ b/Lib/ipaddress.py @@ -195,11 +195,7 @@ def _count_righthand_zero_bits(number, bits): """ if number == 0: return bits - for i in range(bits): - if (number >> i) & 1: - return i - # All bits of interest were zero, even if there are more in the number - return bits + return min(bits, (~number & (number-1)).bit_length()) def summarize_address_range(first, last): @@ -250,15 +246,14 @@ def summarize_address_range(first, last): while first_int <= last_int: nbits = min(_count_righthand_zero_bits(first_int, ip_bits), (last_int - first_int + 1).bit_length() - 1) - net = ip('%s/%d' % (first, ip_bits - nbits)) + net = ip((first_int, ip_bits - nbits)) yield net first_int += 1 << nbits if first_int - 1 == ip._ALL_ONES: break - first = first.__class__(first_int) -def _collapse_addresses_recursive(addresses): +def _collapse_addresses_internal(addresses): """Loops through the addresses, collapsing concurrent netblocks. Example: @@ -268,7 +263,7 @@ def _collapse_addresses_recursive(addresses): ip3 = IPv4Network('192.0.2.128/26') ip4 = IPv4Network('192.0.2.192/26') - _collapse_addresses_recursive([ip1, ip2, ip3, ip4]) -> + _collapse_addresses_internal([ip1, ip2, ip3, ip4]) -> [IPv4Network('192.0.2.0/24')] This shouldn't be called directly; it is called via @@ -282,28 +277,29 @@ def _collapse_addresses_recursive(addresses): passed. """ - while True: - last_addr = None - ret_array = [] - optimized = False - - for cur_addr in addresses: - if not ret_array: - last_addr = cur_addr - ret_array.append(cur_addr) - elif (cur_addr.network_address >= last_addr.network_address and - cur_addr.broadcast_address <= last_addr.broadcast_address): - optimized = True - elif cur_addr == list(last_addr.supernet().subnets())[1]: - ret_array[-1] = last_addr = last_addr.supernet() - optimized = True - else: - last_addr = cur_addr - ret_array.append(cur_addr) - - addresses = ret_array - if not optimized: - return addresses + # First merge + to_merge = list(addresses) + subnets = {} + while to_merge: + net = to_merge.pop() + supernet = net.supernet() + existing = subnets.get(supernet) + if existing is None: + subnets[supernet] = net + elif existing != net: + # Merge consecutive subnets + del subnets[supernet] + to_merge.append(supernet) + # Then iterate over resulting networks, skipping subsumed subnets + last = None + for net in sorted(subnets.values()): + if last is not None: + # Since they are sorted, last.network_address <= net.network_address + # is a given. + if last.broadcast_address >= net.broadcast_address: + continue + yield net + last = net def collapse_addresses(addresses): @@ -352,15 +348,13 @@ def collapse_addresses(addresses): # sort and dedup ips = sorted(set(ips)) - nets = sorted(set(nets)) while i < len(ips): (first, last) = _find_address_range(ips[i:]) i = ips.index(last) + 1 addrs.extend(summarize_address_range(first, last)) - return iter(_collapse_addresses_recursive(sorted( - addrs + nets, key=_BaseNetwork._get_networks_key))) + return _collapse_addresses_internal(addrs + nets) def get_mixed_type_key(obj): @@ -436,6 +430,17 @@ class _IPAddressBase(_TotalOrderingMixin): return str(self) @property + def reverse_pointer(self): + """The name of the reverse DNS pointer for the IP address, e.g.: + >>> ipaddress.ip_address("127.0.0.1").reverse_pointer + '1.0.0.127.in-addr.arpa' + >>> ipaddress.ip_address("2001:db8::1").reverse_pointer + '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa' + + """ + return self._reverse_pointer() + + @property def version(self): msg = '%200s has no version specified' % (type(self),) raise NotImplementedError(msg) @@ -456,7 +461,8 @@ class _IPAddressBase(_TotalOrderingMixin): raise AddressValueError(msg % (address, address_len, expected_len, self._version)) - def _ip_int_from_prefix(self, prefixlen): + @classmethod + def _ip_int_from_prefix(cls, prefixlen): """Turn the prefix length into a bitwise netmask Args: @@ -466,9 +472,10 @@ class _IPAddressBase(_TotalOrderingMixin): An integer. """ - return self._ALL_ONES ^ (self._ALL_ONES >> prefixlen) + return cls._ALL_ONES ^ (cls._ALL_ONES >> prefixlen) - def _prefix_from_ip_int(self, ip_int): + @classmethod + def _prefix_from_ip_int(cls, ip_int): """Return prefix length from the bitwise netmask. Args: @@ -481,22 +488,24 @@ class _IPAddressBase(_TotalOrderingMixin): ValueError: If the input intermingles zeroes & ones """ trailing_zeroes = _count_righthand_zero_bits(ip_int, - self._max_prefixlen) - prefixlen = self._max_prefixlen - trailing_zeroes + cls._max_prefixlen) + prefixlen = cls._max_prefixlen - trailing_zeroes leading_ones = ip_int >> trailing_zeroes all_ones = (1 << prefixlen) - 1 if leading_ones != all_ones: - byteslen = self._max_prefixlen // 8 + byteslen = cls._max_prefixlen // 8 details = ip_int.to_bytes(byteslen, 'big') msg = 'Netmask pattern %r mixes zeroes & ones' raise ValueError(msg % details) return prefixlen - def _report_invalid_netmask(self, netmask_str): + @classmethod + def _report_invalid_netmask(cls, netmask_str): msg = '%r is not a valid netmask' % netmask_str raise NetmaskValueError(msg) from None - def _prefix_from_prefix_string(self, prefixlen_str): + @classmethod + def _prefix_from_prefix_string(cls, prefixlen_str): """Return prefix length from a numeric string Args: @@ -511,16 +520,17 @@ class _IPAddressBase(_TotalOrderingMixin): # int allows a leading +/- as well as surrounding whitespace, # so we ensure that isn't the case if not _BaseV4._DECIMAL_DIGITS.issuperset(prefixlen_str): - self._report_invalid_netmask(prefixlen_str) + cls._report_invalid_netmask(prefixlen_str) try: prefixlen = int(prefixlen_str) except ValueError: - self._report_invalid_netmask(prefixlen_str) - if not (0 <= prefixlen <= self._max_prefixlen): - self._report_invalid_netmask(prefixlen_str) + cls._report_invalid_netmask(prefixlen_str) + if not (0 <= prefixlen <= cls._max_prefixlen): + cls._report_invalid_netmask(prefixlen_str) return prefixlen - def _prefix_from_ip_string(self, ip_str): + @classmethod + def _prefix_from_ip_string(cls, ip_str): """Turn a netmask/hostmask string into a prefix length Args: @@ -534,24 +544,24 @@ class _IPAddressBase(_TotalOrderingMixin): """ # Parse the netmask/hostmask like an IP address. try: - ip_int = self._ip_int_from_string(ip_str) + ip_int = cls._ip_int_from_string(ip_str) except AddressValueError: - self._report_invalid_netmask(ip_str) + cls._report_invalid_netmask(ip_str) # Try matching a netmask (this would be /1*0*/ as a bitwise regexp). # Note that the two ambiguous cases (all-ones and all-zeroes) are # treated as netmasks. try: - return self._prefix_from_ip_int(ip_int) + return cls._prefix_from_ip_int(ip_int) except ValueError: pass # Invert the bits, and try matching a /0+1+/ hostmask instead. - ip_int ^= self._ALL_ONES + ip_int ^= cls._ALL_ONES try: - return self._prefix_from_ip_int(ip_int) + return cls._prefix_from_ip_int(ip_int) except ValueError: - self._report_invalid_netmask(ip_str) + cls._report_invalid_netmask(ip_str) class _BaseAddress(_IPAddressBase): @@ -933,20 +943,11 @@ class _BaseNetwork(_IPAddressBase): 'prefix length diff %d is invalid for netblock %s' % ( new_prefixlen, self)) - first = self.__class__('%s/%s' % - (self.network_address, - self._prefixlen + prefixlen_diff)) - - yield first - current = first - while True: - broadcast = current.broadcast_address - if broadcast == self.broadcast_address: - return - new_addr = self._address_class(int(broadcast) + 1) - current = self.__class__('%s/%s' % (new_addr, - new_prefixlen)) - + start = int(self.network_address) + end = int(self.broadcast_address) + step = (int(self.hostmask) + 1) >> prefixlen_diff + for new_addr in range(start, end, step): + current = self.__class__((new_addr, new_prefixlen)) yield current def supernet(self, prefixlen_diff=1, new_prefix=None): @@ -980,15 +981,15 @@ class _BaseNetwork(_IPAddressBase): raise ValueError('cannot set prefixlen_diff and new_prefix') prefixlen_diff = self._prefixlen - new_prefix - if self.prefixlen - prefixlen_diff < 0: + new_prefixlen = self.prefixlen - prefixlen_diff + if new_prefixlen < 0: raise ValueError( 'current prefixlen is %d, cannot have a prefixlen_diff of %d' % (self.prefixlen, prefixlen_diff)) - # TODO (pmoody): optimize this. - t = self.__class__('%s/%d' % (self.network_address, - self.prefixlen - prefixlen_diff), - strict=False) - return t.__class__('%s/%d' % (t.network_address, t.prefixlen)) + return self.__class__(( + int(self.network_address) & (int(self.netmask) << prefixlen_diff), + new_prefixlen + )) @property def is_multicast(self): @@ -1089,14 +1090,43 @@ class _BaseV4: # the valid octets for host and netmasks. only useful for IPv4. _valid_mask_octets = frozenset((255, 254, 252, 248, 240, 224, 192, 128, 0)) + _max_prefixlen = IPV4LENGTH + # There are only a handful of valid v4 netmasks, so we cache them all + # when constructed (see _make_netmask()). + _netmask_cache = {} + def __init__(self, address): self._version = 4 - self._max_prefixlen = IPV4LENGTH def _explode_shorthand_ip_string(self): return str(self) - def _ip_int_from_string(self, ip_str): + @classmethod + def _make_netmask(cls, arg): + """Make a (netmask, prefix_len) tuple from the given argument. + + Argument can be: + - an integer (the prefix length) + - a string representing the prefix length (e.g. "24") + - a string representing the prefix netmask (e.g. "255.255.255.0") + """ + if arg not in cls._netmask_cache: + if isinstance(arg, int): + prefixlen = arg + else: + try: + # Check for a netmask in prefix length form + prefixlen = cls._prefix_from_prefix_string(arg) + except NetmaskValueError: + # Check for a netmask or hostmask in dotted-quad form. + # This may raise NetmaskValueError. + prefixlen = cls._prefix_from_ip_string(arg) + netmask = IPv4Address(cls._ip_int_from_prefix(prefixlen)) + cls._netmask_cache[arg] = netmask, prefixlen + return cls._netmask_cache[arg] + + @classmethod + def _ip_int_from_string(cls, ip_str): """Turn the given IP string into an integer for comparison. Args: @@ -1117,11 +1147,12 @@ class _BaseV4: raise AddressValueError("Expected 4 octets in %r" % ip_str) try: - return int.from_bytes(map(self._parse_octet, octets), 'big') + return int.from_bytes(map(cls._parse_octet, octets), 'big') except ValueError as exc: raise AddressValueError("%s in %r" % (exc, ip_str)) from None - def _parse_octet(self, octet_str): + @classmethod + def _parse_octet(cls, octet_str): """Convert a decimal octet into an integer. Args: @@ -1137,7 +1168,7 @@ class _BaseV4: if not octet_str: raise ValueError("Empty octet not permitted") # Whitelist the characters, since int() allows a lot of bizarre stuff. - if not self._DECIMAL_DIGITS.issuperset(octet_str): + if not cls._DECIMAL_DIGITS.issuperset(octet_str): msg = "Only decimal digits permitted in %r" raise ValueError(msg % octet_str) # We do the length check second, since the invalid character error @@ -1157,7 +1188,8 @@ class _BaseV4: raise ValueError("Octet %d (> 255) not permitted" % octet_int) return octet_int - def _string_from_ip_int(self, ip_int): + @classmethod + def _string_from_ip_int(cls, ip_int): """Turns a 32-bit integer into dotted decimal notation. Args: @@ -1221,6 +1253,15 @@ class _BaseV4: return True return False + def _reverse_pointer(self): + """Return the reverse DNS pointer name for the IPv4 address. + + This implements the method described in RFC1035 3.5. + + """ + reverse_octets = str(self).split('.')[::-1] + return '.'.join(reverse_octets) + '.in-addr.arpa' + @property def max_prefixlen(self): return self._max_prefixlen @@ -1284,8 +1325,7 @@ class IPv4Address(_BaseV4, _BaseAddress): reserved IPv4 Network range. """ - reserved_network = IPv4Network('240.0.0.0/4') - return self in reserved_network + return self in self._constants._reserved_network @property @functools.lru_cache() @@ -1297,21 +1337,7 @@ class IPv4Address(_BaseV4, _BaseAddress): iana-ipv4-special-registry. """ - return (self in IPv4Network('0.0.0.0/8') or - self in IPv4Network('10.0.0.0/8') or - self in IPv4Network('127.0.0.0/8') or - self in IPv4Network('169.254.0.0/16') or - self in IPv4Network('172.16.0.0/12') or - self in IPv4Network('192.0.0.0/29') or - self in IPv4Network('192.0.0.170/31') or - self in IPv4Network('192.0.2.0/24') or - self in IPv4Network('192.168.0.0/16') or - self in IPv4Network('198.18.0.0/15') or - self in IPv4Network('198.51.100.0/24') or - self in IPv4Network('203.0.113.0/24') or - self in IPv4Network('240.0.0.0/4') or - self in IPv4Network('255.255.255.255/32')) - + return any(self in net for net in self._constants._private_networks) @property def is_multicast(self): @@ -1322,8 +1348,7 @@ class IPv4Address(_BaseV4, _BaseAddress): See RFC 3171 for details. """ - multicast_network = IPv4Network('224.0.0.0/4') - return self in multicast_network + return self in self._constants._multicast_network @property def is_unspecified(self): @@ -1334,8 +1359,7 @@ class IPv4Address(_BaseV4, _BaseAddress): RFC 5735 3. """ - unspecified_address = IPv4Address('0.0.0.0') - return self == unspecified_address + return self == self._constants._unspecified_address @property def is_loopback(self): @@ -1345,8 +1369,7 @@ class IPv4Address(_BaseV4, _BaseAddress): A boolean, True if the address is a loopback per RFC 3330. """ - loopback_network = IPv4Network('127.0.0.0/8') - return self in loopback_network + return self in self._constants._loopback_network @property def is_link_local(self): @@ -1356,8 +1379,7 @@ class IPv4Address(_BaseV4, _BaseAddress): A boolean, True if the address is link-local per RFC 3927. """ - linklocal_network = IPv4Network('169.254.0.0/16') - return self in linklocal_network + return self in self._constants._linklocal_network class IPv4Interface(IPv4Address): @@ -1369,6 +1391,18 @@ class IPv4Interface(IPv4Address): self._prefixlen = self._max_prefixlen return + if isinstance(address, tuple): + IPv4Address.__init__(self, address[0]) + if len(address) > 1: + self._prefixlen = int(address[1]) + else: + self._prefixlen = self._max_prefixlen + + self.network = IPv4Network(address, strict=False) + self.netmask = self.network.netmask + self.hostmask = self.network.hostmask + return + addr = _split_optional_netmask(address) IPv4Address.__init__(self, addr[0]) @@ -1484,20 +1518,28 @@ class IPv4Network(_BaseV4, _BaseNetwork): _BaseV4.__init__(self, address) _BaseNetwork.__init__(self, address) - # Constructing from a packed address - if isinstance(address, bytes): + # Constructing from a packed address or integer + if isinstance(address, (int, bytes)): self.network_address = IPv4Address(address) - self._prefixlen = self._max_prefixlen - self.netmask = IPv4Address(self._ALL_ONES) - #fixme: address/network test here + self.netmask, self._prefixlen = self._make_netmask(self._max_prefixlen) + #fixme: address/network test here. return - # Efficient constructor from integer. - if isinstance(address, int): - self.network_address = IPv4Address(address) - self._prefixlen = self._max_prefixlen - self.netmask = IPv4Address(self._ALL_ONES) - #fixme: address/network test here. + if isinstance(address, tuple): + if len(address) > 1: + arg = address[1] + else: + # We weren't given an address[1] + arg = self._max_prefixlen + self.network_address = IPv4Address(address[0]) + self.netmask, self._prefixlen = self._make_netmask(arg) + packed = int(self.network_address) + if packed & int(self.netmask) != packed: + if strict: + raise ValueError('%s has host bits set' % self) + else: + self.network_address = IPv4Address(packed & + int(self.netmask)) return # Assume input argument to be string or any object representation @@ -1506,16 +1548,10 @@ class IPv4Network(_BaseV4, _BaseNetwork): self.network_address = IPv4Address(self._ip_int_from_string(addr[0])) if len(addr) == 2: - try: - # Check for a netmask in prefix length form - self._prefixlen = self._prefix_from_prefix_string(addr[1]) - except NetmaskValueError: - # Check for a netmask or hostmask in dotted-quad form. - # This may raise NetmaskValueError. - self._prefixlen = self._prefix_from_ip_string(addr[1]) + arg = addr[1] else: - self._prefixlen = self._max_prefixlen - self.netmask = IPv4Address(self._ip_int_from_prefix(self._prefixlen)) + arg = self._max_prefixlen + self.netmask, self._prefixlen = self._make_netmask(arg) if strict: if (IPv4Address(int(self.network_address) & int(self.netmask)) != @@ -1542,6 +1578,37 @@ class IPv4Network(_BaseV4, _BaseNetwork): not self.is_private) +class _IPv4Constants: + _linklocal_network = IPv4Network('169.254.0.0/16') + + _loopback_network = IPv4Network('127.0.0.0/8') + + _multicast_network = IPv4Network('224.0.0.0/4') + + _private_networks = [ + IPv4Network('0.0.0.0/8'), + IPv4Network('10.0.0.0/8'), + IPv4Network('127.0.0.0/8'), + IPv4Network('169.254.0.0/16'), + IPv4Network('172.16.0.0/12'), + IPv4Network('192.0.0.0/29'), + IPv4Network('192.0.0.170/31'), + IPv4Network('192.0.2.0/24'), + IPv4Network('192.168.0.0/16'), + IPv4Network('198.18.0.0/15'), + IPv4Network('198.51.100.0/24'), + IPv4Network('203.0.113.0/24'), + IPv4Network('240.0.0.0/4'), + IPv4Network('255.255.255.255/32'), + ] + + _reserved_network = IPv4Network('240.0.0.0/4') + + _unspecified_address = IPv4Address('0.0.0.0') + + +IPv4Address._constants = _IPv4Constants + class _BaseV6: @@ -1555,12 +1622,35 @@ class _BaseV6: _ALL_ONES = (2**IPV6LENGTH) - 1 _HEXTET_COUNT = 8 _HEX_DIGITS = frozenset('0123456789ABCDEFabcdef') + _max_prefixlen = IPV6LENGTH + + # There are only a bunch of valid v6 netmasks, so we cache them all + # when constructed (see _make_netmask()). + _netmask_cache = {} def __init__(self, address): self._version = 6 - self._max_prefixlen = IPV6LENGTH - def _ip_int_from_string(self, ip_str): + @classmethod + def _make_netmask(cls, arg): + """Make a (netmask, prefix_len) tuple from the given argument. + + Argument can be: + - an integer (the prefix length) + - a string representing the prefix length (e.g. "24") + - a string representing the prefix netmask (e.g. "255.255.255.0") + """ + if arg not in cls._netmask_cache: + if isinstance(arg, int): + prefixlen = arg + else: + prefixlen = cls._prefix_from_prefix_string(arg) + netmask = IPv6Address(cls._ip_int_from_prefix(prefixlen)) + cls._netmask_cache[arg] = netmask, prefixlen + return cls._netmask_cache[arg] + + @classmethod + def _ip_int_from_string(cls, ip_str): """Turn an IPv6 ip_str into an integer. Args: @@ -1596,7 +1686,7 @@ class _BaseV6: # An IPv6 address can't have more than 8 colons (9 parts). # The extra colon comes from using the "::" notation for a single # leading or trailing zero part. - _max_parts = self._HEXTET_COUNT + 1 + _max_parts = cls._HEXTET_COUNT + 1 if len(parts) > _max_parts: msg = "At most %d colons permitted in %r" % (_max_parts-1, ip_str) raise AddressValueError(msg) @@ -1628,17 +1718,17 @@ class _BaseV6: if parts_lo: msg = "Trailing ':' only permitted as part of '::' in %r" raise AddressValueError(msg % ip_str) # :$ requires ::$ - parts_skipped = self._HEXTET_COUNT - (parts_hi + parts_lo) + parts_skipped = cls._HEXTET_COUNT - (parts_hi + parts_lo) if parts_skipped < 1: msg = "Expected at most %d other parts with '::' in %r" - raise AddressValueError(msg % (self._HEXTET_COUNT-1, ip_str)) + raise AddressValueError(msg % (cls._HEXTET_COUNT-1, ip_str)) else: # Otherwise, allocate the entire address to parts_hi. The # endpoints could still be empty, but _parse_hextet() will check # for that. - if len(parts) != self._HEXTET_COUNT: + if len(parts) != cls._HEXTET_COUNT: msg = "Exactly %d parts expected without '::' in %r" - raise AddressValueError(msg % (self._HEXTET_COUNT, ip_str)) + raise AddressValueError(msg % (cls._HEXTET_COUNT, ip_str)) if not parts[0]: msg = "Leading ':' only permitted as part of '::' in %r" raise AddressValueError(msg % ip_str) # ^: requires ^:: @@ -1654,16 +1744,17 @@ class _BaseV6: ip_int = 0 for i in range(parts_hi): ip_int <<= 16 - ip_int |= self._parse_hextet(parts[i]) + ip_int |= cls._parse_hextet(parts[i]) ip_int <<= 16 * parts_skipped for i in range(-parts_lo, 0): ip_int <<= 16 - ip_int |= self._parse_hextet(parts[i]) + ip_int |= cls._parse_hextet(parts[i]) return ip_int except ValueError as exc: raise AddressValueError("%s in %r" % (exc, ip_str)) from None - def _parse_hextet(self, hextet_str): + @classmethod + def _parse_hextet(cls, hextet_str): """Convert an IPv6 hextet string into an integer. Args: @@ -1678,7 +1769,7 @@ class _BaseV6: """ # Whitelist the characters, since int() allows a lot of bizarre stuff. - if not self._HEX_DIGITS.issuperset(hextet_str): + if not cls._HEX_DIGITS.issuperset(hextet_str): raise ValueError("Only hex digits permitted in %r" % hextet_str) # We do the length check second, since the invalid character error # is likely to be more informative for the user @@ -1688,7 +1779,8 @@ class _BaseV6: # Length check means we can skip checking the integer value return int(hextet_str, 16) - def _compress_hextets(self, hextets): + @classmethod + def _compress_hextets(cls, hextets): """Compresses a list of hextets. Compresses a list of strings, replacing the longest continuous @@ -1735,7 +1827,8 @@ class _BaseV6: return hextets - def _string_from_ip_int(self, ip_int=None): + @classmethod + def _string_from_ip_int(cls, ip_int=None): """Turns a 128-bit integer into hexadecimal notation. Args: @@ -1749,15 +1842,15 @@ class _BaseV6: """ if ip_int is None: - ip_int = int(self._ip) + ip_int = int(cls._ip) - if ip_int > self._ALL_ONES: + if ip_int > cls._ALL_ONES: raise ValueError('IPv6 address is too large') hex_str = '%032x' % ip_int hextets = ['%x' % int(hex_str[x:x+4], 16) for x in range(0, 32, 4)] - hextets = self._compress_hextets(hextets) + hextets = cls._compress_hextets(hextets) return ':'.join(hextets) def _explode_shorthand_ip_string(self): @@ -1784,6 +1877,15 @@ class _BaseV6: return '%s/%d' % (':'.join(parts), self._prefixlen) return ':'.join(parts) + def _reverse_pointer(self): + """Return the reverse DNS pointer name for the IPv6 address. + + This implements the method described in RFC3596 2.5. + + """ + reverse_chars = self.exploded[::-1].replace(':', '') + return '.'.join(reverse_chars) + '.ip6.arpa' + @property def max_prefixlen(self): return self._max_prefixlen @@ -1848,8 +1950,7 @@ class IPv6Address(_BaseV6, _BaseAddress): See RFC 2373 2.7 for details. """ - multicast_network = IPv6Network('ff00::/8') - return self in multicast_network + return self in self._constants._multicast_network @property def is_reserved(self): @@ -1860,16 +1961,7 @@ class IPv6Address(_BaseV6, _BaseAddress): reserved IPv6 Network ranges. """ - reserved_networks = [IPv6Network('::/8'), IPv6Network('100::/8'), - IPv6Network('200::/7'), IPv6Network('400::/6'), - IPv6Network('800::/5'), IPv6Network('1000::/4'), - IPv6Network('4000::/3'), IPv6Network('6000::/3'), - IPv6Network('8000::/3'), IPv6Network('A000::/3'), - IPv6Network('C000::/3'), IPv6Network('E000::/4'), - IPv6Network('F000::/5'), IPv6Network('F800::/6'), - IPv6Network('FE00::/9')] - - return any(self in x for x in reserved_networks) + return any(self in x for x in self._constants._reserved_networks) @property def is_link_local(self): @@ -1879,8 +1971,7 @@ class IPv6Address(_BaseV6, _BaseAddress): A boolean, True if the address is reserved per RFC 4291. """ - linklocal_network = IPv6Network('fe80::/10') - return self in linklocal_network + return self in self._constants._linklocal_network @property def is_site_local(self): @@ -1894,8 +1985,7 @@ class IPv6Address(_BaseV6, _BaseAddress): A boolean, True if the address is reserved per RFC 3513 2.5.6. """ - sitelocal_network = IPv6Network('fec0::/10') - return self in sitelocal_network + return self in self._constants._sitelocal_network @property @functools.lru_cache() @@ -1907,16 +1997,7 @@ class IPv6Address(_BaseV6, _BaseAddress): iana-ipv6-special-registry. """ - return (self in IPv6Network('::1/128') or - self in IPv6Network('::/128') or - self in IPv6Network('::ffff:0:0/96') or - self in IPv6Network('100::/64') or - self in IPv6Network('2001::/23') or - self in IPv6Network('2001:2::/48') or - self in IPv6Network('2001:db8::/32') or - self in IPv6Network('2001:10::/28') or - self in IPv6Network('fc00::/7') or - self in IPv6Network('fe80::/10')) + return any(self in net for net in self._constants._private_networks) @property def is_global(self): @@ -2001,6 +2082,16 @@ class IPv6Interface(IPv6Address): self.network = IPv6Network(self._ip) self._prefixlen = self._max_prefixlen return + if isinstance(address, tuple): + IPv6Address.__init__(self, address[0]) + if len(address) > 1: + self._prefixlen = int(address[1]) + else: + self._prefixlen = self._max_prefixlen + self.network = IPv6Network(address, strict=False) + self.netmask = self.network.netmask + self.hostmask = self.network.hostmask + return addr = _split_optional_netmask(address) IPv6Address.__init__(self, addr[0]) @@ -2118,18 +2209,26 @@ class IPv6Network(_BaseV6, _BaseNetwork): _BaseV6.__init__(self, address) _BaseNetwork.__init__(self, address) - # Efficient constructor from integer. - if isinstance(address, int): + # Efficient constructor from integer or packed address + if isinstance(address, (bytes, int)): self.network_address = IPv6Address(address) - self._prefixlen = self._max_prefixlen - self.netmask = IPv6Address(self._ALL_ONES) + self.netmask, self._prefixlen = self._make_netmask(self._max_prefixlen) return - # Constructing from a packed address - if isinstance(address, bytes): - self.network_address = IPv6Address(address) - self._prefixlen = self._max_prefixlen - self.netmask = IPv6Address(self._ALL_ONES) + if isinstance(address, tuple): + if len(address) > 1: + arg = address[1] + else: + arg = self._max_prefixlen + self.netmask, self._prefixlen = self._make_netmask(arg) + self.network_address = IPv6Address(address[0]) + packed = int(self.network_address) + if packed & int(self.netmask) != packed: + if strict: + raise ValueError('%s has host bits set' % self) + else: + self.network_address = IPv6Address(packed & + int(self.netmask)) return # Assume input argument to be string or any object representation @@ -2139,12 +2238,11 @@ class IPv6Network(_BaseV6, _BaseNetwork): self.network_address = IPv6Address(self._ip_int_from_string(addr[0])) if len(addr) == 2: - # This may raise NetmaskValueError - self._prefixlen = self._prefix_from_prefix_string(addr[1]) + arg = addr[1] else: - self._prefixlen = self._max_prefixlen + arg = self._max_prefixlen + self.netmask, self._prefixlen = self._make_netmask(arg) - self.netmask = IPv6Address(self._ip_int_from_prefix(self._prefixlen)) if strict: if (IPv6Address(int(self.network_address) & int(self.netmask)) != self.network_address): @@ -2181,3 +2279,39 @@ class IPv6Network(_BaseV6, _BaseNetwork): """ return (self.network_address.is_site_local and self.broadcast_address.is_site_local) + + +class _IPv6Constants: + + _linklocal_network = IPv6Network('fe80::/10') + + _multicast_network = IPv6Network('ff00::/8') + + _private_networks = [ + IPv6Network('::1/128'), + IPv6Network('::/128'), + IPv6Network('::ffff:0:0/96'), + IPv6Network('100::/64'), + IPv6Network('2001::/23'), + IPv6Network('2001:2::/48'), + IPv6Network('2001:db8::/32'), + IPv6Network('2001:10::/28'), + IPv6Network('fc00::/7'), + IPv6Network('fe80::/10'), + ] + + _reserved_networks = [ + IPv6Network('::/8'), IPv6Network('100::/8'), + IPv6Network('200::/7'), IPv6Network('400::/6'), + IPv6Network('800::/5'), IPv6Network('1000::/4'), + IPv6Network('4000::/3'), IPv6Network('6000::/3'), + IPv6Network('8000::/3'), IPv6Network('A000::/3'), + IPv6Network('C000::/3'), IPv6Network('E000::/4'), + IPv6Network('F000::/5'), IPv6Network('F800::/6'), + IPv6Network('FE00::/9'), + ] + + _sitelocal_network = IPv6Network('fec0::/10') + + +IPv6Address._constants = _IPv6Constants diff --git a/Lib/json/tool.py b/Lib/json/tool.py index 7db4528..cd57e4f 100644 --- a/Lib/json/tool.py +++ b/Lib/json/tool.py @@ -10,21 +10,24 @@ Usage:: Expecting property name enclosed in double quotes: line 1 column 3 (char 2) """ -import sys +import argparse import json +import sys + def main(): - if len(sys.argv) == 1: - infile = sys.stdin - outfile = sys.stdout - elif len(sys.argv) == 2: - infile = open(sys.argv[1], 'r') - outfile = sys.stdout - elif len(sys.argv) == 3: - infile = open(sys.argv[1], 'r') - outfile = open(sys.argv[2], 'w') - else: - raise SystemExit(sys.argv[0] + " [infile [outfile]]") + prog = 'python -m json.tool' + description = ('A simple command line interface for json module ' + 'to validate and pretty-print JSON objects.') + parser = argparse.ArgumentParser(prog=prog, description=description) + parser.add_argument('infile', nargs='?', type=argparse.FileType(), + help='a JSON file to be validated or pretty-printed') + parser.add_argument('outfile', nargs='?', type=argparse.FileType('w'), + help='write the output of infile to outfile') + options = parser.parse_args() + + infile = options.infile or sys.stdin + outfile = options.outfile or sys.stdout with infile: try: obj = json.load(infile) diff --git a/Lib/logging/config.py b/Lib/logging/config.py index 895fb26..8a99923 100644 --- a/Lib/logging/config.py +++ b/Lib/logging/config.py @@ -116,11 +116,12 @@ def _create_formatters(cp): sectname = "formatter_%s" % form fs = cp.get(sectname, "format", raw=True, fallback=None) dfs = cp.get(sectname, "datefmt", raw=True, fallback=None) + stl = cp.get(sectname, "style", raw=True, fallback='%') c = logging.Formatter class_name = cp[sectname].get("class") if class_name: c = _resolve(class_name) - f = c(fs, dfs) + f = c(fs, dfs, stl) formatters[form] = f return formatters @@ -660,7 +661,12 @@ class DictConfigurator(BaseConfigurator): fmt = config.get('format', None) dfmt = config.get('datefmt', None) style = config.get('style', '%') - result = logging.Formatter(fmt, dfmt, style) + cname = config.get('class', None) + if not cname: + c = logging.Formatter + else: + c = _resolve(cname) + result = c(fmt, dfmt, style) return result def configure_filter(self, config): diff --git a/Lib/multiprocessing/dummy/connection.py b/Lib/multiprocessing/dummy/connection.py index 694ef96..1984375 100644 --- a/Lib/multiprocessing/dummy/connection.py +++ b/Lib/multiprocessing/dummy/connection.py @@ -59,9 +59,8 @@ class Connection(object): return True if timeout <= 0.0: return False - self._in.not_empty.acquire() - self._in.not_empty.wait(timeout) - self._in.not_empty.release() + with self._in.not_empty: + self._in.not_empty.wait(timeout) return self._in.qsize() > 0 def close(self): diff --git a/Lib/multiprocessing/heap.py b/Lib/multiprocessing/heap.py index 344a45f..9e3016c 100644 --- a/Lib/multiprocessing/heap.py +++ b/Lib/multiprocessing/heap.py @@ -216,9 +216,8 @@ class Heap(object): assert 0 <= size < sys.maxsize if os.getpid() != self._lastpid: self.__init__() # reinitialize after fork - self._lock.acquire() - self._free_pending_blocks() - try: + with self._lock: + self._free_pending_blocks() size = self._roundup(max(size,1), self._alignment) (arena, start, stop) = self._malloc(size) new_stop = start + size @@ -227,8 +226,6 @@ class Heap(object): block = (arena, start, new_stop) self._allocated_blocks.add(block) return block - finally: - self._lock.release() # # Class representing a chunk of an mmap -- can be inherited by child process diff --git a/Lib/multiprocessing/managers.py b/Lib/multiprocessing/managers.py index 66d46fc..820ae91 100644 --- a/Lib/multiprocessing/managers.py +++ b/Lib/multiprocessing/managers.py @@ -306,8 +306,7 @@ class Server(object): ''' Return some info --- useful to spot problems with refcounting ''' - self.mutex.acquire() - try: + with self.mutex: result = [] keys = list(self.id_to_obj.keys()) keys.sort() @@ -317,8 +316,6 @@ class Server(object): (ident, self.id_to_refcount[ident], str(self.id_to_obj[ident][0])[:75])) return '\n'.join(result) - finally: - self.mutex.release() def number_of_objects(self, c): ''' @@ -343,8 +340,7 @@ class Server(object): ''' Create a new shared object and return its id ''' - self.mutex.acquire() - try: + with self.mutex: callable, exposed, method_to_typeid, proxytype = \ self.registry[typeid] @@ -374,8 +370,6 @@ class Server(object): # has been created. self.incref(c, ident) return ident, tuple(exposed) - finally: - self.mutex.release() def get_methods(self, c, token): ''' @@ -392,22 +386,16 @@ class Server(object): self.serve_client(c) def incref(self, c, ident): - self.mutex.acquire() - try: + with self.mutex: self.id_to_refcount[ident] += 1 - finally: - self.mutex.release() def decref(self, c, ident): - self.mutex.acquire() - try: + with self.mutex: assert self.id_to_refcount[ident] >= 1 self.id_to_refcount[ident] -= 1 if self.id_to_refcount[ident] == 0: del self.id_to_obj[ident], self.id_to_refcount[ident] util.debug('disposing of obj with id %r', ident) - finally: - self.mutex.release() # # Class to represent state of a manager @@ -671,14 +659,11 @@ class BaseProxy(object): def __init__(self, token, serializer, manager=None, authkey=None, exposed=None, incref=True): - BaseProxy._mutex.acquire() - try: + with BaseProxy._mutex: tls_idset = BaseProxy._address_to_local.get(token.address, None) if tls_idset is None: tls_idset = util.ForkAwareLocal(), ProcessLocalSet() BaseProxy._address_to_local[token.address] = tls_idset - finally: - BaseProxy._mutex.release() # self._tls is used to record the connection used by this # thread to communicate with the manager at token.address diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py index 8832a5c..77eb817 100644 --- a/Lib/multiprocessing/pool.py +++ b/Lib/multiprocessing/pool.py @@ -666,8 +666,7 @@ class IMapIterator(object): return self def next(self, timeout=None): - self._cond.acquire() - try: + with self._cond: try: item = self._items.popleft() except IndexError: @@ -680,8 +679,6 @@ class IMapIterator(object): if self._index == self._length: raise StopIteration raise TimeoutError - finally: - self._cond.release() success, value = item if success: @@ -691,8 +688,7 @@ class IMapIterator(object): __next__ = next # XXX def _set(self, i, obj): - self._cond.acquire() - try: + with self._cond: if self._index == i: self._items.append(obj) self._index += 1 @@ -706,18 +702,13 @@ class IMapIterator(object): if self._index == self._length: del self._cache[self._job] - finally: - self._cond.release() def _set_length(self, length): - self._cond.acquire() - try: + with self._cond: self._length = length if self._index == self._length: self._cond.notify() del self._cache[self._job] - finally: - self._cond.release() # # Class whose instances are returned by `Pool.imap_unordered()` @@ -726,15 +717,12 @@ class IMapIterator(object): class IMapUnorderedIterator(IMapIterator): def _set(self, i, obj): - self._cond.acquire() - try: + with self._cond: self._items.append(obj) self._index += 1 self._cond.notify() if self._index == self._length: del self._cache[self._job] - finally: - self._cond.release() # # @@ -760,10 +748,7 @@ class ThreadPool(Pool): @staticmethod def _help_stuff_finish(inqueue, task_handler, size): # put sentinels at head of inqueue to make workers finish - inqueue.not_empty.acquire() - try: + with inqueue.not_empty: inqueue.queue.clear() inqueue.queue.extend([None] * size) inqueue.not_empty.notify_all() - finally: - inqueue.not_empty.release() diff --git a/Lib/multiprocessing/queues.py b/Lib/multiprocessing/queues.py index f650771..c07ad40 100644 --- a/Lib/multiprocessing/queues.py +++ b/Lib/multiprocessing/queues.py @@ -81,14 +81,11 @@ class Queue(object): if not self._sem.acquire(block, timeout): raise Full - self._notempty.acquire() - try: + with self._notempty: if self._thread is None: self._start_thread() self._buffer.append(obj) self._notempty.notify() - finally: - self._notempty.release() def get(self, block=True, timeout=None): if block and timeout is None: @@ -201,12 +198,9 @@ class Queue(object): @staticmethod def _finalize_close(buffer, notempty): debug('telling queue thread to quit') - notempty.acquire() - try: + with notempty: buffer.append(_sentinel) notempty.notify() - finally: - notempty.release() @staticmethod def _feed(buffer, notempty, send_bytes, writelock, close, ignore_epipe): @@ -295,35 +289,24 @@ class JoinableQueue(Queue): if not self._sem.acquire(block, timeout): raise Full - self._notempty.acquire() - self._cond.acquire() - try: + with self._notempty, self._cond: if self._thread is None: self._start_thread() self._buffer.append(obj) self._unfinished_tasks.release() self._notempty.notify() - finally: - self._cond.release() - self._notempty.release() def task_done(self): - self._cond.acquire() - try: + with self._cond: if not self._unfinished_tasks.acquire(False): raise ValueError('task_done() called too many times') if self._unfinished_tasks._semlock._is_zero(): self._cond.notify_all() - finally: - self._cond.release() def join(self): - self._cond.acquire() - try: + with self._cond: if not self._unfinished_tasks._semlock._is_zero(): self._cond.wait() - finally: - self._cond.release() # # Simplified Queue type -- really just a locked pipe diff --git a/Lib/multiprocessing/sharedctypes.py b/Lib/multiprocessing/sharedctypes.py index 0c17825..4258f59 100644 --- a/Lib/multiprocessing/sharedctypes.py +++ b/Lib/multiprocessing/sharedctypes.py @@ -188,6 +188,12 @@ class SynchronizedBase(object): self.acquire = self._lock.acquire self.release = self._lock.release + def __enter__(self): + return self._lock.__enter__() + + def __exit__(self, *args): + return self._lock.__exit__(*args) + def __reduce__(self): assert_spawning(self) return synchronized, (self._obj, self._lock) @@ -212,32 +218,20 @@ class SynchronizedArray(SynchronizedBase): return len(self._obj) def __getitem__(self, i): - self.acquire() - try: + with self: return self._obj[i] - finally: - self.release() def __setitem__(self, i, value): - self.acquire() - try: + with self: self._obj[i] = value - finally: - self.release() def __getslice__(self, start, stop): - self.acquire() - try: + with self: return self._obj[start:stop] - finally: - self.release() def __setslice__(self, start, stop, values): - self.acquire() - try: + with self: self._obj[start:stop] = values - finally: - self.release() class SynchronizedString(SynchronizedArray): diff --git a/Lib/multiprocessing/synchronize.py b/Lib/multiprocessing/synchronize.py index dea1cbd..7d44330 100644 --- a/Lib/multiprocessing/synchronize.py +++ b/Lib/multiprocessing/synchronize.py @@ -337,34 +337,24 @@ class Event(object): self._flag = ctx.Semaphore(0) def is_set(self): - self._cond.acquire() - try: + with self._cond: if self._flag.acquire(False): self._flag.release() return True return False - finally: - self._cond.release() def set(self): - self._cond.acquire() - try: + with self._cond: self._flag.acquire(False) self._flag.release() self._cond.notify_all() - finally: - self._cond.release() def clear(self): - self._cond.acquire() - try: + with self._cond: self._flag.acquire(False) - finally: - self._cond.release() def wait(self, timeout=None): - self._cond.acquire() - try: + with self._cond: if self._flag.acquire(False): self._flag.release() else: @@ -374,8 +364,6 @@ class Event(object): self._flag.release() return True return False - finally: - self._cond.release() # # Barrier diff --git a/Lib/multiprocessing/util.py b/Lib/multiprocessing/util.py index 0b695e4..8760c82 100644 --- a/Lib/multiprocessing/util.py +++ b/Lib/multiprocessing/util.py @@ -327,6 +327,13 @@ class ForkAwareThreadLock(object): self.acquire = self._lock.acquire self.release = self._lock.release + def __enter__(self): + return self._lock.__enter__() + + def __exit__(self, *args): + return self._lock.__exit__(*args) + + class ForkAwareLocal(threading.local): def __init__(self): register_after_fork(self, lambda obj : obj.__dict__.clear()) diff --git a/Lib/opcode.py b/Lib/opcode.py index 0bd1ee6..bfd3c4d 100644 --- a/Lib/opcode.py +++ b/Lib/opcode.py @@ -70,6 +70,9 @@ def_op('UNARY_NOT', 12) def_op('UNARY_INVERT', 15) +def_op('BINARY_MATRIX_MULTIPLY', 16) +def_op('INPLACE_MATRIX_MULTIPLY', 17) + def_op('BINARY_POWER', 19) def_op('BINARY_MULTIPLY', 20) diff --git a/Lib/operator.py b/Lib/operator.py index b60349f..856036d 100644 --- a/Lib/operator.py +++ b/Lib/operator.py @@ -105,6 +105,10 @@ def mul(a, b): "Same as a * b." return a * b +def matmul(a, b): + "Same as a @ b." + return a @ b + def neg(a): "Same as -a." return -a @@ -326,6 +330,11 @@ def imul(a, b): a *= b return a +def imatmul(a, b): + "Same as a @= b." + a @= b + return a + def ior(a, b): "Same as a |= b." a |= b @@ -383,6 +392,7 @@ __invert__ = invert __lshift__ = lshift __mod__ = mod __mul__ = mul +__matmul__ = matmul __neg__ = neg __or__ = or_ __pos__ = pos @@ -403,6 +413,7 @@ __ifloordiv__ = ifloordiv __ilshift__ = ilshift __imod__ = imod __imul__ = imul +__imatmul__ = imatmul __ior__ = ior __ipow__ = ipow __irshift__ = irshift diff --git a/Lib/pathlib.py b/Lib/pathlib.py index 48b7031..428de39 100644 --- a/Lib/pathlib.py +++ b/Lib/pathlib.py @@ -964,6 +964,17 @@ class Path(PurePath): """ return cls(os.getcwd()) + def samefile(self, other_path): + """Return whether `other_file` is the same or not as this file. + (as returned by os.path.samefile(file, other_file)). + """ + st = self.stat() + try: + other_st = other_path.stat() + except AttributeError: + other_st = os.stat(other_path) + return os.path.samestat(st, other_st) + def iterdir(self): """Iterate over the files in this directory. Does not yield any result for the special paths '.' and '..'. diff --git a/Lib/pkgutil.py b/Lib/pkgutil.py index a54e947..fc4a074 100644 --- a/Lib/pkgutil.py +++ b/Lib/pkgutil.py @@ -616,7 +616,7 @@ def get_data(package, resource): return None # XXX needs test mod = (sys.modules.get(package) or - importlib._bootstrap._SpecMethods(spec).load()) + importlib._bootstrap._load(spec)) if mod is None or not hasattr(mod, '__file__'): return None diff --git a/Lib/pydoc.py b/Lib/pydoc.py index 37abf67..4c67835 100755 --- a/Lib/pydoc.py +++ b/Lib/pydoc.py @@ -264,9 +264,8 @@ def synopsis(filename, cache={}): # XXX We probably don't need to pass in the loader here. spec = importlib.util.spec_from_file_location('__temp__', filename, loader=loader) - _spec = importlib._bootstrap._SpecMethods(spec) try: - module = _spec.load() + module = importlib._bootstrap._load(spec) except: return None del sys.modules['__temp__'] @@ -298,9 +297,8 @@ def importfile(path): loader = importlib._bootstrap.SourceFileLoader(name, path) # XXX We probably don't need to pass in the loader here. spec = importlib.util.spec_from_file_location(name, path, loader=loader) - _spec = importlib._bootstrap._SpecMethods(spec) try: - return _spec.load() + return importlib._bootstrap._load(spec) except: raise ErrorDuringImport(path, sys.exc_info()) @@ -2062,9 +2060,8 @@ class ModuleScanner: else: path = None else: - _spec = importlib._bootstrap._SpecMethods(spec) try: - module = _spec.load() + module = importlib._bootstrap._load(spec) except ImportError: if onerror: onerror(modname) diff --git a/Lib/pydoc_data/topics.py b/Lib/pydoc_data/topics.py index 0d2d83c..905c7c8 100644 --- a/Lib/pydoc_data/topics.py +++ b/Lib/pydoc_data/topics.py @@ -1,10 +1,10 @@ # -*- coding: utf-8 -*- -# Autogenerated by Sphinx on Sat May 17 21:42:09 2014 +# Autogenerated by Sphinx on Mon Feb 10 04:20:03 2014 topics = {'assert': '\nThe "assert" statement\n**********************\n\nAssert statements are a convenient way to insert debugging assertions\ninto a program:\n\n assert_stmt ::= "assert" expression ["," expression]\n\nThe simple form, "assert expression", is equivalent to\n\n if __debug__:\n if not expression: raise AssertionError\n\nThe extended form, "assert expression1, expression2", is equivalent to\n\n if __debug__:\n if not expression1: raise AssertionError(expression2)\n\nThese equivalences assume that "__debug__" and "AssertionError" refer\nto the built-in variables with those names. In the current\nimplementation, the built-in variable "__debug__" is "True" under\nnormal circumstances, "False" when optimization is requested (command\nline option -O). The current code generator emits no code for an\nassert statement when optimization is requested at compile time. Note\nthat it is unnecessary to include the source code for the expression\nthat failed in the error message; it will be displayed as part of the\nstack trace.\n\nAssignments to "__debug__" are illegal. The value for the built-in\nvariable is determined when the interpreter starts.\n', - 'assignment': '\nAssignment statements\n*********************\n\nAssignment statements are used to (re)bind names to values and to\nmodify attributes or items of mutable objects:\n\n assignment_stmt ::= (target_list "=")+ (expression_list | yield_expression)\n target_list ::= target ("," target)* [","]\n target ::= identifier\n | "(" target_list ")"\n | "[" target_list "]"\n | attributeref\n | subscription\n | slicing\n | "*" target\n\n(See section *Primaries* for the syntax definitions for the last three\nsymbols.)\n\nAn assignment statement evaluates the expression list (remember that\nthis can be a single expression or a comma-separated list, the latter\nyielding a tuple) and assigns the single resulting object to each of\nthe target lists, from left to right.\n\nAssignment is defined recursively depending on the form of the target\n(list). When a target is part of a mutable object (an attribute\nreference, subscription or slicing), the mutable object must\nultimately perform the assignment and decide about its validity, and\nmay raise an exception if the assignment is unacceptable. The rules\nobserved by various types and the exceptions raised are given with the\ndefinition of the object types (see section *The standard type\nhierarchy*).\n\nAssignment of an object to a target list, optionally enclosed in\nparentheses or square brackets, is recursively defined as follows.\n\n* If the target list is a single target: The object is assigned to\n that target.\n\n* If the target list is a comma-separated list of targets: The object\n must be an iterable with the same number of items as there are\n targets in the target list, and the items are assigned, from left to\n right, to the corresponding targets.\n\n * If the target list contains one target prefixed with an asterisk,\n called a "starred" target: The object must be a sequence with at\n least as many items as there are targets in the target list, minus\n one. The first items of the sequence are assigned, from left to\n right, to the targets before the starred target. The final items\n of the sequence are assigned to the targets after the starred\n target. A list of the remaining items in the sequence is then\n assigned to the starred target (the list can be empty).\n\n * Else: The object must be a sequence with the same number of items\n as there are targets in the target list, and the items are\n assigned, from left to right, to the corresponding targets.\n\nAssignment of an object to a single target is recursively defined as\nfollows.\n\n* If the target is an identifier (name):\n\n * If the name does not occur in a "global" or "nonlocal" statement\n in the current code block: the name is bound to the object in the\n current local namespace.\n\n * Otherwise: the name is bound to the object in the global namespace\n or the outer namespace determined by "nonlocal", respectively.\n\n The name is rebound if it was already bound. This may cause the\n reference count for the object previously bound to the name to reach\n zero, causing the object to be deallocated and its destructor (if it\n has one) to be called.\n\n* If the target is a target list enclosed in parentheses or in square\n brackets: The object must be an iterable with the same number of\n items as there are targets in the target list, and its items are\n assigned, from left to right, to the corresponding targets.\n\n* If the target is an attribute reference: The primary expression in\n the reference is evaluated. It should yield an object with\n assignable attributes; if this is not the case, "TypeError" is\n raised. That object is then asked to assign the assigned object to\n the given attribute; if it cannot perform the assignment, it raises\n an exception (usually but not necessarily "AttributeError").\n\n Note: If the object is a class instance and the attribute reference\n occurs on both sides of the assignment operator, the RHS expression,\n "a.x" can access either an instance attribute or (if no instance\n attribute exists) a class attribute. The LHS target "a.x" is always\n set as an instance attribute, creating it if necessary. Thus, the\n two occurrences of "a.x" do not necessarily refer to the same\n attribute: if the RHS expression refers to a class attribute, the\n LHS creates a new instance attribute as the target of the\n assignment:\n\n class Cls:\n x = 3 # class variable\n inst = Cls()\n inst.x = inst.x + 1 # writes inst.x as 4 leaving Cls.x as 3\n\n This description does not necessarily apply to descriptor\n attributes, such as properties created with "property()".\n\n* If the target is a subscription: The primary expression in the\n reference is evaluated. It should yield either a mutable sequence\n object (such as a list) or a mapping object (such as a dictionary).\n Next, the subscript expression is evaluated.\n\n If the primary is a mutable sequence object (such as a list), the\n subscript must yield an integer. If it is negative, the sequence\'s\n length is added to it. The resulting value must be a nonnegative\n integer less than the sequence\'s length, and the sequence is asked\n to assign the assigned object to its item with that index. If the\n index is out of range, "IndexError" is raised (assignment to a\n subscripted sequence cannot add new items to a list).\n\n If the primary is a mapping object (such as a dictionary), the\n subscript must have a type compatible with the mapping\'s key type,\n and the mapping is then asked to create a key/datum pair which maps\n the subscript to the assigned object. This can either replace an\n existing key/value pair with the same key value, or insert a new\n key/value pair (if no key with the same value existed).\n\n For user-defined objects, the "__setitem__()" method is called with\n appropriate arguments.\n\n* If the target is a slicing: The primary expression in the reference\n is evaluated. It should yield a mutable sequence object (such as a\n list). The assigned object should be a sequence object of the same\n type. Next, the lower and upper bound expressions are evaluated,\n insofar they are present; defaults are zero and the sequence\'s\n length. The bounds should evaluate to integers. If either bound is\n negative, the sequence\'s length is added to it. The resulting\n bounds are clipped to lie between zero and the sequence\'s length,\n inclusive. Finally, the sequence object is asked to replace the\n slice with the items of the assigned sequence. The length of the\n slice may be different from the length of the assigned sequence,\n thus changing the length of the target sequence, if the object\n allows it.\n\n**CPython implementation detail:** In the current implementation, the\nsyntax for targets is taken to be the same as for expressions, and\ninvalid syntax is rejected during the code generation phase, causing\nless detailed error messages.\n\nWARNING: Although the definition of assignment implies that overlaps\nbetween the left-hand side and the right-hand side are \'safe\' (for\nexample "a, b = b, a" swaps two variables), overlaps *within* the\ncollection of assigned-to variables are not safe! For instance, the\nfollowing program prints "[0, 2]":\n\n x = [0, 1]\n i = 0\n i, x[i] = 1, 2\n print(x)\n\nSee also:\n\n **PEP 3132** - Extended Iterable Unpacking\n The specification for the "*target" feature.\n\n\nAugmented assignment statements\n===============================\n\nAugmented assignment is the combination, in a single statement, of a\nbinary operation and an assignment statement:\n\n augmented_assignment_stmt ::= augtarget augop (expression_list | yield_expression)\n augtarget ::= identifier | attributeref | subscription | slicing\n augop ::= "+=" | "-=" | "*=" | "/=" | "//=" | "%=" | "**="\n | ">>=" | "<<=" | "&=" | "^=" | "|="\n\n(See section *Primaries* for the syntax definitions for the last three\nsymbols.)\n\nAn augmented assignment evaluates the target (which, unlike normal\nassignment statements, cannot be an unpacking) and the expression\nlist, performs the binary operation specific to the type of assignment\non the two operands, and assigns the result to the original target.\nThe target is only evaluated once.\n\nAn augmented assignment expression like "x += 1" can be rewritten as\n"x = x + 1" to achieve a similar, but not exactly equal effect. In the\naugmented version, "x" is only evaluated once. Also, when possible,\nthe actual operation is performed *in-place*, meaning that rather than\ncreating a new object and assigning that to the target, the old object\nis modified instead.\n\nWith the exception of assigning to tuples and multiple targets in a\nsingle statement, the assignment done by augmented assignment\nstatements is handled the same way as normal assignments. Similarly,\nwith the exception of the possible *in-place* behavior, the binary\noperation performed by augmented assignment is the same as the normal\nbinary operations.\n\nFor targets which are attribute references, the same *caveat about\nclass and instance attributes* applies as for regular assignments.\n', + 'assignment': '\nAssignment statements\n*********************\n\nAssignment statements are used to (re)bind names to values and to\nmodify attributes or items of mutable objects:\n\n assignment_stmt ::= (target_list "=")+ (expression_list | yield_expression)\n target_list ::= target ("," target)* [","]\n target ::= identifier\n | "(" target_list ")"\n | "[" target_list "]"\n | attributeref\n | subscription\n | slicing\n | "*" target\n\n(See section *Primaries* for the syntax definitions for the last three\nsymbols.)\n\nAn assignment statement evaluates the expression list (remember that\nthis can be a single expression or a comma-separated list, the latter\nyielding a tuple) and assigns the single resulting object to each of\nthe target lists, from left to right.\n\nAssignment is defined recursively depending on the form of the target\n(list). When a target is part of a mutable object (an attribute\nreference, subscription or slicing), the mutable object must\nultimately perform the assignment and decide about its validity, and\nmay raise an exception if the assignment is unacceptable. The rules\nobserved by various types and the exceptions raised are given with the\ndefinition of the object types (see section *The standard type\nhierarchy*).\n\nAssignment of an object to a target list, optionally enclosed in\nparentheses or square brackets, is recursively defined as follows.\n\n* If the target list is a single target: The object is assigned to\n that target.\n\n* If the target list is a comma-separated list of targets: The\n object must be an iterable with the same number of items as there\n are targets in the target list, and the items are assigned, from\n left to right, to the corresponding targets.\n\n * If the target list contains one target prefixed with an\n asterisk, called a "starred" target: The object must be a sequence\n with at least as many items as there are targets in the target\n list, minus one. The first items of the sequence are assigned,\n from left to right, to the targets before the starred target. The\n final items of the sequence are assigned to the targets after the\n starred target. A list of the remaining items in the sequence is\n then assigned to the starred target (the list can be empty).\n\n * Else: The object must be a sequence with the same number of\n items as there are targets in the target list, and the items are\n assigned, from left to right, to the corresponding targets.\n\nAssignment of an object to a single target is recursively defined as\nfollows.\n\n* If the target is an identifier (name):\n\n * If the name does not occur in a "global" or "nonlocal" statement\n in the current code block: the name is bound to the object in the\n current local namespace.\n\n * Otherwise: the name is bound to the object in the global\n namespace or the outer namespace determined by "nonlocal",\n respectively.\n\n The name is rebound if it was already bound. This may cause the\n reference count for the object previously bound to the name to reach\n zero, causing the object to be deallocated and its destructor (if it\n has one) to be called.\n\n* If the target is a target list enclosed in parentheses or in\n square brackets: The object must be an iterable with the same number\n of items as there are targets in the target list, and its items are\n assigned, from left to right, to the corresponding targets.\n\n* If the target is an attribute reference: The primary expression in\n the reference is evaluated. It should yield an object with\n assignable attributes; if this is not the case, "TypeError" is\n raised. That object is then asked to assign the assigned object to\n the given attribute; if it cannot perform the assignment, it raises\n an exception (usually but not necessarily "AttributeError").\n\n Note: If the object is a class instance and the attribute reference\n occurs on both sides of the assignment operator, the RHS expression,\n "a.x" can access either an instance attribute or (if no instance\n attribute exists) a class attribute. The LHS target "a.x" is always\n set as an instance attribute, creating it if necessary. Thus, the\n two occurrences of "a.x" do not necessarily refer to the same\n attribute: if the RHS expression refers to a class attribute, the\n LHS creates a new instance attribute as the target of the\n assignment:\n\n class Cls:\n x = 3 # class variable\n inst = Cls()\n inst.x = inst.x + 1 # writes inst.x as 4 leaving Cls.x as 3\n\n This description does not necessarily apply to descriptor\n attributes, such as properties created with "property()".\n\n* If the target is a subscription: The primary expression in the\n reference is evaluated. It should yield either a mutable sequence\n object (such as a list) or a mapping object (such as a dictionary).\n Next, the subscript expression is evaluated.\n\n If the primary is a mutable sequence object (such as a list), the\n subscript must yield an integer. If it is negative, the sequence\'s\n length is added to it. The resulting value must be a nonnegative\n integer less than the sequence\'s length, and the sequence is asked\n to assign the assigned object to its item with that index. If the\n index is out of range, "IndexError" is raised (assignment to a\n subscripted sequence cannot add new items to a list).\n\n If the primary is a mapping object (such as a dictionary), the\n subscript must have a type compatible with the mapping\'s key type,\n and the mapping is then asked to create a key/datum pair which maps\n the subscript to the assigned object. This can either replace an\n existing key/value pair with the same key value, or insert a new\n key/value pair (if no key with the same value existed).\n\n For user-defined objects, the "__setitem__()" method is called with\n appropriate arguments.\n\n* If the target is a slicing: The primary expression in the\n reference is evaluated. It should yield a mutable sequence object\n (such as a list). The assigned object should be a sequence object\n of the same type. Next, the lower and upper bound expressions are\n evaluated, insofar they are present; defaults are zero and the\n sequence\'s length. The bounds should evaluate to integers. If\n either bound is negative, the sequence\'s length is added to it. The\n resulting bounds are clipped to lie between zero and the sequence\'s\n length, inclusive. Finally, the sequence object is asked to replace\n the slice with the items of the assigned sequence. The length of\n the slice may be different from the length of the assigned sequence,\n thus changing the length of the target sequence, if the object\n allows it.\n\n**CPython implementation detail:** In the current implementation, the\nsyntax for targets is taken to be the same as for expressions, and\ninvalid syntax is rejected during the code generation phase, causing\nless detailed error messages.\n\nWARNING: Although the definition of assignment implies that overlaps\nbetween the left-hand side and the right-hand side are \'safe\' (for\nexample "a, b = b, a" swaps two variables), overlaps *within* the\ncollection of assigned-to variables are not safe! For instance, the\nfollowing program prints "[0, 2]":\n\n x = [0, 1]\n i = 0\n i, x[i] = 1, 2\n print(x)\n\nSee also: **PEP 3132** - Extended Iterable Unpacking\n\n The specification for the "*target" feature.\n\n\nAugmented assignment statements\n===============================\n\nAugmented assignment is the combination, in a single statement, of a\nbinary operation and an assignment statement:\n\n augmented_assignment_stmt ::= augtarget augop (expression_list | yield_expression)\n augtarget ::= identifier | attributeref | subscription | slicing\n augop ::= "+=" | "-=" | "*=" | "/=" | "//=" | "%=" | "**="\n | ">>=" | "<<=" | "&=" | "^=" | "|="\n\n(See section *Primaries* for the syntax definitions for the last three\nsymbols.)\n\nAn augmented assignment evaluates the target (which, unlike normal\nassignment statements, cannot be an unpacking) and the expression\nlist, performs the binary operation specific to the type of assignment\non the two operands, and assigns the result to the original target.\nThe target is only evaluated once.\n\nAn augmented assignment expression like "x += 1" can be rewritten as\n"x = x + 1" to achieve a similar, but not exactly equal effect. In the\naugmented version, "x" is only evaluated once. Also, when possible,\nthe actual operation is performed *in-place*, meaning that rather than\ncreating a new object and assigning that to the target, the old object\nis modified instead.\n\nWith the exception of assigning to tuples and multiple targets in a\nsingle statement, the assignment done by augmented assignment\nstatements is handled the same way as normal assignments. Similarly,\nwith the exception of the possible *in-place* behavior, the binary\noperation performed by augmented assignment is the same as the normal\nbinary operations.\n\nFor targets which are attribute references, the same *caveat about\nclass and instance attributes* applies as for regular assignments.\n', 'atom-identifiers': '\nIdentifiers (Names)\n*******************\n\nAn identifier occurring as an atom is a name. See section\n*Identifiers and keywords* for lexical definition and section *Naming\nand binding* for documentation of naming and binding.\n\nWhen the name is bound to an object, evaluation of the atom yields\nthat object. When a name is not bound, an attempt to evaluate it\nraises a "NameError" exception.\n\n**Private name mangling:** When an identifier that textually occurs in\na class definition begins with two or more underscore characters and\ndoes not end in two or more underscores, it is considered a *private\nname* of that class. Private names are transformed to a longer form\nbefore code is generated for them. The transformation inserts the\nclass name, with leading underscores removed and a single underscore\ninserted, in front of the name. For example, the identifier "__spam"\noccurring in a class named "Ham" will be transformed to "_Ham__spam".\nThis transformation is independent of the syntactical context in which\nthe identifier is used. If the transformed name is extremely long\n(longer than 255 characters), implementation defined truncation may\nhappen. If the class name consists only of underscores, no\ntransformation is done.\n', 'atom-literals': "\nLiterals\n********\n\nPython supports string and bytes literals and various numeric\nliterals:\n\n literal ::= stringliteral | bytesliteral\n | integer | floatnumber | imagnumber\n\nEvaluation of a literal yields an object of the given type (string,\nbytes, integer, floating point number, complex number) with the given\nvalue. The value may be approximated in the case of floating point\nand imaginary (complex) literals. See section *Literals* for details.\n\nAll literals correspond to immutable data types, and hence the\nobject's identity is less important than its value. Multiple\nevaluations of literals with the same value (either the same\noccurrence in the program text or a different occurrence) may obtain\nthe same object or a different object with the same value.\n", - 'attribute-access': '\nCustomizing attribute access\n****************************\n\nThe following methods can be defined to customize the meaning of\nattribute access (use of, assignment to, or deletion of "x.name") for\nclass instances.\n\nobject.__getattr__(self, name)\n\n Called when an attribute lookup has not found the attribute in the\n usual places (i.e. it is not an instance attribute nor is it found\n in the class tree for "self"). "name" is the attribute name. This\n method should return the (computed) attribute value or raise an\n "AttributeError" exception.\n\n Note that if the attribute is found through the normal mechanism,\n "__getattr__()" is not called. (This is an intentional asymmetry\n between "__getattr__()" and "__setattr__()".) This is done both for\n efficiency reasons and because otherwise "__getattr__()" would have\n no way to access other attributes of the instance. Note that at\n least for instance variables, you can fake total control by not\n inserting any values in the instance attribute dictionary (but\n instead inserting them in another object). See the\n "__getattribute__()" method below for a way to actually get total\n control over attribute access.\n\nobject.__getattribute__(self, name)\n\n Called unconditionally to implement attribute accesses for\n instances of the class. If the class also defines "__getattr__()",\n the latter will not be called unless "__getattribute__()" either\n calls it explicitly or raises an "AttributeError". This method\n should return the (computed) attribute value or raise an\n "AttributeError" exception. In order to avoid infinite recursion in\n this method, its implementation should always call the base class\n method with the same name to access any attributes it needs, for\n example, "object.__getattribute__(self, name)".\n\n Note: This method may still be bypassed when looking up special methods\n as the result of implicit invocation via language syntax or\n built-in functions. See *Special method lookup*.\n\nobject.__setattr__(self, name, value)\n\n Called when an attribute assignment is attempted. This is called\n instead of the normal mechanism (i.e. store the value in the\n instance dictionary). *name* is the attribute name, *value* is the\n value to be assigned to it.\n\n If "__setattr__()" wants to assign to an instance attribute, it\n should call the base class method with the same name, for example,\n "object.__setattr__(self, name, value)".\n\nobject.__delattr__(self, name)\n\n Like "__setattr__()" but for attribute deletion instead of\n assignment. This should only be implemented if "del obj.name" is\n meaningful for the object.\n\nobject.__dir__(self)\n\n Called when "dir()" is called on the object. A sequence must be\n returned. "dir()" converts the returned sequence to a list and\n sorts it.\n\n\nImplementing Descriptors\n========================\n\nThe following methods only apply when an instance of the class\ncontaining the method (a so-called *descriptor* class) appears in an\n*owner* class (the descriptor must be in either the owner\'s class\ndictionary or in the class dictionary for one of its parents). In the\nexamples below, "the attribute" refers to the attribute whose name is\nthe key of the property in the owner class\' "__dict__".\n\nobject.__get__(self, instance, owner)\n\n Called to get the attribute of the owner class (class attribute\n access) or of an instance of that class (instance attribute\n access). *owner* is always the owner class, while *instance* is the\n instance that the attribute was accessed through, or "None" when\n the attribute is accessed through the *owner*. This method should\n return the (computed) attribute value or raise an "AttributeError"\n exception.\n\nobject.__set__(self, instance, value)\n\n Called to set the attribute on an instance *instance* of the owner\n class to a new value, *value*.\n\nobject.__delete__(self, instance)\n\n Called to delete the attribute on an instance *instance* of the\n owner class.\n\nThe attribute "__objclass__" is interpreted by the "inspect" module as\nspecifying the class where this object was defined (setting this\nappropriately can assist in runtime introspection of dynamic class\nattributes). For callables, it may indicate that an instance of the\ngiven type (or a subclass) is expected or required as the first\npositional argument (for example, CPython sets this attribute for\nunbound methods that are implemented in C).\n\n\nInvoking Descriptors\n====================\n\nIn general, a descriptor is an object attribute with "binding\nbehavior", one whose attribute access has been overridden by methods\nin the descriptor protocol: "__get__()", "__set__()", and\n"__delete__()". If any of those methods are defined for an object, it\nis said to be a descriptor.\n\nThe default behavior for attribute access is to get, set, or delete\nthe attribute from an object\'s dictionary. For instance, "a.x" has a\nlookup chain starting with "a.__dict__[\'x\']", then\n"type(a).__dict__[\'x\']", and continuing through the base classes of\n"type(a)" excluding metaclasses.\n\nHowever, if the looked-up value is an object defining one of the\ndescriptor methods, then Python may override the default behavior and\ninvoke the descriptor method instead. Where this occurs in the\nprecedence chain depends on which descriptor methods were defined and\nhow they were called.\n\nThe starting point for descriptor invocation is a binding, "a.x". How\nthe arguments are assembled depends on "a":\n\nDirect Call\n The simplest and least common call is when user code directly\n invokes a descriptor method: "x.__get__(a)".\n\nInstance Binding\n If binding to an object instance, "a.x" is transformed into the\n call: "type(a).__dict__[\'x\'].__get__(a, type(a))".\n\nClass Binding\n If binding to a class, "A.x" is transformed into the call:\n "A.__dict__[\'x\'].__get__(None, A)".\n\nSuper Binding\n If "a" is an instance of "super", then the binding "super(B,\n obj).m()" searches "obj.__class__.__mro__" for the base class "A"\n immediately preceding "B" and then invokes the descriptor with the\n call: "A.__dict__[\'m\'].__get__(obj, obj.__class__)".\n\nFor instance bindings, the precedence of descriptor invocation depends\non the which descriptor methods are defined. A descriptor can define\nany combination of "__get__()", "__set__()" and "__delete__()". If it\ndoes not define "__get__()", then accessing the attribute will return\nthe descriptor object itself unless there is a value in the object\'s\ninstance dictionary. If the descriptor defines "__set__()" and/or\n"__delete__()", it is a data descriptor; if it defines neither, it is\na non-data descriptor. Normally, data descriptors define both\n"__get__()" and "__set__()", while non-data descriptors have just the\n"__get__()" method. Data descriptors with "__set__()" and "__get__()"\ndefined always override a redefinition in an instance dictionary. In\ncontrast, non-data descriptors can be overridden by instances.\n\nPython methods (including "staticmethod()" and "classmethod()") are\nimplemented as non-data descriptors. Accordingly, instances can\nredefine and override methods. This allows individual instances to\nacquire behaviors that differ from other instances of the same class.\n\nThe "property()" function is implemented as a data descriptor.\nAccordingly, instances cannot override the behavior of a property.\n\n\n__slots__\n=========\n\nBy default, instances of classes have a dictionary for attribute\nstorage. This wastes space for objects having very few instance\nvariables. The space consumption can become acute when creating large\nnumbers of instances.\n\nThe default can be overridden by defining *__slots__* in a class\ndefinition. The *__slots__* declaration takes a sequence of instance\nvariables and reserves just enough space in each instance to hold a\nvalue for each variable. Space is saved because *__dict__* is not\ncreated for each instance.\n\nobject.__slots__\n\n This class variable can be assigned a string, iterable, or sequence\n of strings with variable names used by instances. If defined in a\n class, *__slots__* reserves space for the declared variables and\n prevents the automatic creation of *__dict__* and *__weakref__* for\n each instance.\n\n\nNotes on using *__slots__*\n--------------------------\n\n* When inheriting from a class without *__slots__*, the *__dict__*\n attribute of that class will always be accessible, so a *__slots__*\n definition in the subclass is meaningless.\n\n* Without a *__dict__* variable, instances cannot be assigned new\n variables not listed in the *__slots__* definition. Attempts to\n assign to an unlisted variable name raises "AttributeError". If\n dynamic assignment of new variables is desired, then add\n "\'__dict__\'" to the sequence of strings in the *__slots__*\n declaration.\n\n* Without a *__weakref__* variable for each instance, classes defining\n *__slots__* do not support weak references to its instances. If weak\n reference support is needed, then add "\'__weakref__\'" to the\n sequence of strings in the *__slots__* declaration.\n\n* *__slots__* are implemented at the class level by creating\n descriptors (*Implementing Descriptors*) for each variable name. As\n a result, class attributes cannot be used to set default values for\n instance variables defined by *__slots__*; otherwise, the class\n attribute would overwrite the descriptor assignment.\n\n* The action of a *__slots__* declaration is limited to the class\n where it is defined. As a result, subclasses will have a *__dict__*\n unless they also define *__slots__* (which must only contain names\n of any *additional* slots).\n\n* If a class defines a slot also defined in a base class, the instance\n variable defined by the base class slot is inaccessible (except by\n retrieving its descriptor directly from the base class). This\n renders the meaning of the program undefined. In the future, a\n check may be added to prevent this.\n\n* Nonempty *__slots__* does not work for classes derived from\n "variable-length" built-in types such as "int", "bytes" and "tuple".\n\n* Any non-string iterable may be assigned to *__slots__*. Mappings may\n also be used; however, in the future, special meaning may be\n assigned to the values corresponding to each key.\n\n* *__class__* assignment works only if both classes have the same\n *__slots__*.\n', + 'attribute-access': '\nCustomizing attribute access\n****************************\n\nThe following methods can be defined to customize the meaning of\nattribute access (use of, assignment to, or deletion of "x.name") for\nclass instances.\n\nobject.__getattr__(self, name)\n\n Called when an attribute lookup has not found the attribute in the\n usual places (i.e. it is not an instance attribute nor is it found\n in the class tree for "self"). "name" is the attribute name. This\n method should return the (computed) attribute value or raise an\n "AttributeError" exception.\n\n Note that if the attribute is found through the normal mechanism,\n "__getattr__()" is not called. (This is an intentional asymmetry\n between "__getattr__()" and "__setattr__()".) This is done both for\n efficiency reasons and because otherwise "__getattr__()" would have\n no way to access other attributes of the instance. Note that at\n least for instance variables, you can fake total control by not\n inserting any values in the instance attribute dictionary (but\n instead inserting them in another object). See the\n "__getattribute__()" method below for a way to actually get total\n control over attribute access.\n\nobject.__getattribute__(self, name)\n\n Called unconditionally to implement attribute accesses for\n instances of the class. If the class also defines "__getattr__()",\n the latter will not be called unless "__getattribute__()" either\n calls it explicitly or raises an "AttributeError". This method\n should return the (computed) attribute value or raise an\n "AttributeError" exception. In order to avoid infinite recursion in\n this method, its implementation should always call the base class\n method with the same name to access any attributes it needs, for\n example, "object.__getattribute__(self, name)".\n\n Note: This method may still be bypassed when looking up special\n methods as the result of implicit invocation via language syntax\n or built-in functions. See *Special method lookup*.\n\nobject.__setattr__(self, name, value)\n\n Called when an attribute assignment is attempted. This is called\n instead of the normal mechanism (i.e. store the value in the\n instance dictionary). *name* is the attribute name, *value* is the\n value to be assigned to it.\n\n If "__setattr__()" wants to assign to an instance attribute, it\n should call the base class method with the same name, for example,\n "object.__setattr__(self, name, value)".\n\nobject.__delattr__(self, name)\n\n Like "__setattr__()" but for attribute deletion instead of\n assignment. This should only be implemented if "del obj.name" is\n meaningful for the object.\n\nobject.__dir__(self)\n\n Called when "dir()" is called on the object. A sequence must be\n returned. "dir()" converts the returned sequence to a list and\n sorts it.\n\n\nImplementing Descriptors\n========================\n\nThe following methods only apply when an instance of the class\ncontaining the method (a so-called *descriptor* class) appears in an\n*owner* class (the descriptor must be in either the owner\'s class\ndictionary or in the class dictionary for one of its parents). In the\nexamples below, "the attribute" refers to the attribute whose name is\nthe key of the property in the owner class\' "__dict__".\n\nobject.__get__(self, instance, owner)\n\n Called to get the attribute of the owner class (class attribute\n access) or of an instance of that class (instance attribute\n access). *owner* is always the owner class, while *instance* is the\n instance that the attribute was accessed through, or "None" when\n the attribute is accessed through the *owner*. This method should\n return the (computed) attribute value or raise an "AttributeError"\n exception.\n\nobject.__set__(self, instance, value)\n\n Called to set the attribute on an instance *instance* of the owner\n class to a new value, *value*.\n\nobject.__delete__(self, instance)\n\n Called to delete the attribute on an instance *instance* of the\n owner class.\n\n\nInvoking Descriptors\n====================\n\nIn general, a descriptor is an object attribute with "binding\nbehavior", one whose attribute access has been overridden by methods\nin the descriptor protocol: "__get__()", "__set__()", and\n"__delete__()". If any of those methods are defined for an object, it\nis said to be a descriptor.\n\nThe default behavior for attribute access is to get, set, or delete\nthe attribute from an object\'s dictionary. For instance, "a.x" has a\nlookup chain starting with "a.__dict__[\'x\']", then\n"type(a).__dict__[\'x\']", and continuing through the base classes of\n"type(a)" excluding metaclasses.\n\nHowever, if the looked-up value is an object defining one of the\ndescriptor methods, then Python may override the default behavior and\ninvoke the descriptor method instead. Where this occurs in the\nprecedence chain depends on which descriptor methods were defined and\nhow they were called.\n\nThe starting point for descriptor invocation is a binding, "a.x". How\nthe arguments are assembled depends on "a":\n\nDirect Call\n The simplest and least common call is when user code directly\n invokes a descriptor method: "x.__get__(a)".\n\nInstance Binding\n If binding to an object instance, "a.x" is transformed into the\n call: "type(a).__dict__[\'x\'].__get__(a, type(a))".\n\nClass Binding\n If binding to a class, "A.x" is transformed into the call:\n "A.__dict__[\'x\'].__get__(None, A)".\n\nSuper Binding\n If "a" is an instance of "super", then the binding "super(B,\n obj).m()" searches "obj.__class__.__mro__" for the base class "A"\n immediately preceding "B" and then invokes the descriptor with the\n call: "A.__dict__[\'m\'].__get__(obj, obj.__class__)".\n\nFor instance bindings, the precedence of descriptor invocation depends\non the which descriptor methods are defined. A descriptor can define\nany combination of "__get__()", "__set__()" and "__delete__()". If it\ndoes not define "__get__()", then accessing the attribute will return\nthe descriptor object itself unless there is a value in the object\'s\ninstance dictionary. If the descriptor defines "__set__()" and/or\n"__delete__()", it is a data descriptor; if it defines neither, it is\na non-data descriptor. Normally, data descriptors define both\n"__get__()" and "__set__()", while non-data descriptors have just the\n"__get__()" method. Data descriptors with "__set__()" and "__get__()"\ndefined always override a redefinition in an instance dictionary. In\ncontrast, non-data descriptors can be overridden by instances.\n\nPython methods (including "staticmethod()" and "classmethod()") are\nimplemented as non-data descriptors. Accordingly, instances can\nredefine and override methods. This allows individual instances to\nacquire behaviors that differ from other instances of the same class.\n\nThe "property()" function is implemented as a data descriptor.\nAccordingly, instances cannot override the behavior of a property.\n\n\n__slots__\n=========\n\nBy default, instances of classes have a dictionary for attribute\nstorage. This wastes space for objects having very few instance\nvariables. The space consumption can become acute when creating large\nnumbers of instances.\n\nThe default can be overridden by defining *__slots__* in a class\ndefinition. The *__slots__* declaration takes a sequence of instance\nvariables and reserves just enough space in each instance to hold a\nvalue for each variable. Space is saved because *__dict__* is not\ncreated for each instance.\n\nobject.__slots__\n\n This class variable can be assigned a string, iterable, or sequence\n of strings with variable names used by instances. If defined in a\n class, *__slots__* reserves space for the declared variables and\n prevents the automatic creation of *__dict__* and *__weakref__* for\n each instance.\n\n\nNotes on using *__slots__*\n--------------------------\n\n* When inheriting from a class without *__slots__*, the *__dict__*\n attribute of that class will always be accessible, so a *__slots__*\n definition in the subclass is meaningless.\n\n* Without a *__dict__* variable, instances cannot be assigned new\n variables not listed in the *__slots__* definition. Attempts to\n assign to an unlisted variable name raises "AttributeError". If\n dynamic assignment of new variables is desired, then add\n "\'__dict__\'" to the sequence of strings in the *__slots__*\n declaration.\n\n* Without a *__weakref__* variable for each instance, classes\n defining *__slots__* do not support weak references to its\n instances. If weak reference support is needed, then add\n "\'__weakref__\'" to the sequence of strings in the *__slots__*\n declaration.\n\n* *__slots__* are implemented at the class level by creating\n descriptors (*Implementing Descriptors*) for each variable name. As\n a result, class attributes cannot be used to set default values for\n instance variables defined by *__slots__*; otherwise, the class\n attribute would overwrite the descriptor assignment.\n\n* The action of a *__slots__* declaration is limited to the class\n where it is defined. As a result, subclasses will have a *__dict__*\n unless they also define *__slots__* (which must only contain names\n of any *additional* slots).\n\n* If a class defines a slot also defined in a base class, the\n instance variable defined by the base class slot is inaccessible\n (except by retrieving its descriptor directly from the base class).\n This renders the meaning of the program undefined. In the future, a\n check may be added to prevent this.\n\n* Nonempty *__slots__* does not work for classes derived from\n "variable-length" built-in types such as "int", "bytes" and "tuple".\n\n* Any non-string iterable may be assigned to *__slots__*. Mappings\n may also be used; however, in the future, special meaning may be\n assigned to the values corresponding to each key.\n\n* *__class__* assignment works only if both classes have the same\n *__slots__*.\n', 'attribute-references': '\nAttribute references\n********************\n\nAn attribute reference is a primary followed by a period and a name:\n\n attributeref ::= primary "." identifier\n\nThe primary must evaluate to an object of a type that supports\nattribute references, which most objects do. This object is then\nasked to produce the attribute whose name is the identifier (which can\nbe customized by overriding the "__getattr__()" method). If this\nattribute is not available, the exception "AttributeError" is raised.\nOtherwise, the type and value of the object produced is determined by\nthe object. Multiple evaluations of the same attribute reference may\nyield different objects.\n', 'augassign': '\nAugmented assignment statements\n*******************************\n\nAugmented assignment is the combination, in a single statement, of a\nbinary operation and an assignment statement:\n\n augmented_assignment_stmt ::= augtarget augop (expression_list | yield_expression)\n augtarget ::= identifier | attributeref | subscription | slicing\n augop ::= "+=" | "-=" | "*=" | "/=" | "//=" | "%=" | "**="\n | ">>=" | "<<=" | "&=" | "^=" | "|="\n\n(See section *Primaries* for the syntax definitions for the last three\nsymbols.)\n\nAn augmented assignment evaluates the target (which, unlike normal\nassignment statements, cannot be an unpacking) and the expression\nlist, performs the binary operation specific to the type of assignment\non the two operands, and assigns the result to the original target.\nThe target is only evaluated once.\n\nAn augmented assignment expression like "x += 1" can be rewritten as\n"x = x + 1" to achieve a similar, but not exactly equal effect. In the\naugmented version, "x" is only evaluated once. Also, when possible,\nthe actual operation is performed *in-place*, meaning that rather than\ncreating a new object and assigning that to the target, the old object\nis modified instead.\n\nWith the exception of assigning to tuples and multiple targets in a\nsingle statement, the assignment done by augmented assignment\nstatements is handled the same way as normal assignments. Similarly,\nwith the exception of the possible *in-place* behavior, the binary\noperation performed by augmented assignment is the same as the normal\nbinary operations.\n\nFor targets which are attribute references, the same *caveat about\nclass and instance attributes* applies as for regular assignments.\n', 'binary': '\nBinary arithmetic operations\n****************************\n\nThe binary arithmetic operations have the conventional priority\nlevels. Note that some of these operations also apply to certain non-\nnumeric types. Apart from the power operator, there are only two\nlevels, one for multiplicative operators and one for additive\noperators:\n\n m_expr ::= u_expr | m_expr "*" u_expr | m_expr "//" u_expr | m_expr "/" u_expr\n | m_expr "%" u_expr\n a_expr ::= m_expr | a_expr "+" m_expr | a_expr "-" m_expr\n\nThe "*" (multiplication) operator yields the product of its arguments.\nThe arguments must either both be numbers, or one argument must be an\ninteger and the other must be a sequence. In the former case, the\nnumbers are converted to a common type and then multiplied together.\nIn the latter case, sequence repetition is performed; a negative\nrepetition factor yields an empty sequence.\n\nThe "/" (division) and "//" (floor division) operators yield the\nquotient of their arguments. The numeric arguments are first\nconverted to a common type. Division of integers yields a float, while\nfloor division of integers results in an integer; the result is that\nof mathematical division with the \'floor\' function applied to the\nresult. Division by zero raises the "ZeroDivisionError" exception.\n\nThe "%" (modulo) operator yields the remainder from the division of\nthe first argument by the second. The numeric arguments are first\nconverted to a common type. A zero right argument raises the\n"ZeroDivisionError" exception. The arguments may be floating point\nnumbers, e.g., "3.14%0.7" equals "0.34" (since "3.14" equals "4*0.7 +\n0.34".) The modulo operator always yields a result with the same sign\nas its second operand (or zero); the absolute value of the result is\nstrictly smaller than the absolute value of the second operand [1].\n\nThe floor division and modulo operators are connected by the following\nidentity: "x == (x//y)*y + (x%y)". Floor division and modulo are also\nconnected with the built-in function "divmod()": "divmod(x, y) ==\n(x//y, x%y)". [2].\n\nIn addition to performing the modulo operation on numbers, the "%"\noperator is also overloaded by string objects to perform old-style\nstring formatting (also known as interpolation). The syntax for\nstring formatting is described in the Python Library Reference,\nsection *printf-style String Formatting*.\n\nThe floor division operator, the modulo operator, and the "divmod()"\nfunction are not defined for complex numbers. Instead, convert to a\nfloating point number using the "abs()" function if appropriate.\n\nThe "+" (addition) operator yields the sum of its arguments. The\narguments must either both be numbers or both sequences of the same\ntype. In the former case, the numbers are converted to a common type\nand then added together. In the latter case, the sequences are\nconcatenated.\n\nThe "-" (subtraction) operator yields the difference of its arguments.\nThe numeric arguments are first converted to a common type.\n', @@ -17,63 +17,63 @@ topics = {'assert': '\nThe "assert" statement\n**********************\n\nAssert 'break': '\nThe "break" statement\n*********************\n\n break_stmt ::= "break"\n\n"break" may only occur syntactically nested in a "for" or "while"\nloop, but not nested in a function or class definition within that\nloop.\n\nIt terminates the nearest enclosing loop, skipping the optional "else"\nclause if the loop has one.\n\nIf a "for" loop is terminated by "break", the loop control target\nkeeps its current value.\n\nWhen "break" passes control out of a "try" statement with a "finally"\nclause, that "finally" clause is executed before really leaving the\nloop.\n', 'callable-types': '\nEmulating callable objects\n**************************\n\nobject.__call__(self[, args...])\n\n Called when the instance is "called" as a function; if this method\n is defined, "x(arg1, arg2, ...)" is a shorthand for\n "x.__call__(arg1, arg2, ...)".\n', 'calls': '\nCalls\n*****\n\nA call calls a callable object (e.g., a *function*) with a possibly\nempty series of *arguments*:\n\n call ::= primary "(" [argument_list [","] | comprehension] ")"\n argument_list ::= positional_arguments ["," keyword_arguments]\n ["," "*" expression] ["," keyword_arguments]\n ["," "**" expression]\n | keyword_arguments ["," "*" expression]\n ["," keyword_arguments] ["," "**" expression]\n | "*" expression ["," keyword_arguments] ["," "**" expression]\n | "**" expression\n positional_arguments ::= expression ("," expression)*\n keyword_arguments ::= keyword_item ("," keyword_item)*\n keyword_item ::= identifier "=" expression\n\nA trailing comma may be present after the positional and keyword\narguments but does not affect the semantics.\n\nThe primary must evaluate to a callable object (user-defined\nfunctions, built-in functions, methods of built-in objects, class\nobjects, methods of class instances, and all objects having a\n"__call__()" method are callable). All argument expressions are\nevaluated before the call is attempted. Please refer to section\n*Function definitions* for the syntax of formal *parameter* lists.\n\nIf keyword arguments are present, they are first converted to\npositional arguments, as follows. First, a list of unfilled slots is\ncreated for the formal parameters. If there are N positional\narguments, they are placed in the first N slots. Next, for each\nkeyword argument, the identifier is used to determine the\ncorresponding slot (if the identifier is the same as the first formal\nparameter name, the first slot is used, and so on). If the slot is\nalready filled, a "TypeError" exception is raised. Otherwise, the\nvalue of the argument is placed in the slot, filling it (even if the\nexpression is "None", it fills the slot). When all arguments have\nbeen processed, the slots that are still unfilled are filled with the\ncorresponding default value from the function definition. (Default\nvalues are calculated, once, when the function is defined; thus, a\nmutable object such as a list or dictionary used as default value will\nbe shared by all calls that don\'t specify an argument value for the\ncorresponding slot; this should usually be avoided.) If there are any\nunfilled slots for which no default value is specified, a "TypeError"\nexception is raised. Otherwise, the list of filled slots is used as\nthe argument list for the call.\n\n**CPython implementation detail:** An implementation may provide\nbuilt-in functions whose positional parameters do not have names, even\nif they are \'named\' for the purpose of documentation, and which\ntherefore cannot be supplied by keyword. In CPython, this is the case\nfor functions implemented in C that use "PyArg_ParseTuple()" to parse\ntheir arguments.\n\nIf there are more positional arguments than there are formal parameter\nslots, a "TypeError" exception is raised, unless a formal parameter\nusing the syntax "*identifier" is present; in this case, that formal\nparameter receives a tuple containing the excess positional arguments\n(or an empty tuple if there were no excess positional arguments).\n\nIf any keyword argument does not correspond to a formal parameter\nname, a "TypeError" exception is raised, unless a formal parameter\nusing the syntax "**identifier" is present; in this case, that formal\nparameter receives a dictionary containing the excess keyword\narguments (using the keywords as keys and the argument values as\ncorresponding values), or a (new) empty dictionary if there were no\nexcess keyword arguments.\n\nIf the syntax "*expression" appears in the function call, "expression"\nmust evaluate to an iterable. Elements from this iterable are treated\nas if they were additional positional arguments; if there are\npositional arguments *x1*, ..., *xN*, and "expression" evaluates to a\nsequence *y1*, ..., *yM*, this is equivalent to a call with M+N\npositional arguments *x1*, ..., *xN*, *y1*, ..., *yM*.\n\nA consequence of this is that although the "*expression" syntax may\nappear *after* some keyword arguments, it is processed *before* the\nkeyword arguments (and the "**expression" argument, if any -- see\nbelow). So:\n\n >>> def f(a, b):\n ... print(a, b)\n ...\n >>> f(b=1, *(2,))\n 2 1\n >>> f(a=1, *(2,))\n Traceback (most recent call last):\n File "<stdin>", line 1, in ?\n TypeError: f() got multiple values for keyword argument \'a\'\n >>> f(1, *(2,))\n 1 2\n\nIt is unusual for both keyword arguments and the "*expression" syntax\nto be used in the same call, so in practice this confusion does not\narise.\n\nIf the syntax "**expression" appears in the function call,\n"expression" must evaluate to a mapping, the contents of which are\ntreated as additional keyword arguments. In the case of a keyword\nappearing in both "expression" and as an explicit keyword argument, a\n"TypeError" exception is raised.\n\nFormal parameters using the syntax "*identifier" or "**identifier"\ncannot be used as positional argument slots or as keyword argument\nnames.\n\nA call always returns some value, possibly "None", unless it raises an\nexception. How this value is computed depends on the type of the\ncallable object.\n\nIf it is---\n\na user-defined function:\n The code block for the function is executed, passing it the\n argument list. The first thing the code block will do is bind the\n formal parameters to the arguments; this is described in section\n *Function definitions*. When the code block executes a "return"\n statement, this specifies the return value of the function call.\n\na built-in function or method:\n The result is up to the interpreter; see *Built-in Functions* for\n the descriptions of built-in functions and methods.\n\na class object:\n A new instance of that class is returned.\n\na class instance method:\n The corresponding user-defined function is called, with an argument\n list that is one longer than the argument list of the call: the\n instance becomes the first argument.\n\na class instance:\n The class must define a "__call__()" method; the effect is then the\n same as if that method was called.\n', - 'class': '\nClass definitions\n*****************\n\nA class definition defines a class object (see section *The standard\ntype hierarchy*):\n\n classdef ::= [decorators] "class" classname [inheritance] ":" suite\n inheritance ::= "(" [parameter_list] ")"\n classname ::= identifier\n\nA class definition is an executable statement. The inheritance list\nusually gives a list of base classes (see *Customizing class creation*\nfor more advanced uses), so each item in the list should evaluate to a\nclass object which allows subclassing. Classes without an inheritance\nlist inherit, by default, from the base class "object"; hence,\n\n class Foo:\n pass\n\nis equivalent to\n\n class Foo(object):\n pass\n\nThe class\'s suite is then executed in a new execution frame (see\n*Naming and binding*), using a newly created local namespace and the\noriginal global namespace. (Usually, the suite contains mostly\nfunction definitions.) When the class\'s suite finishes execution, its\nexecution frame is discarded but its local namespace is saved. [4] A\nclass object is then created using the inheritance list for the base\nclasses and the saved local namespace for the attribute dictionary.\nThe class name is bound to this class object in the original local\nnamespace.\n\nClass creation can be customized heavily using *metaclasses*.\n\nClasses can also be decorated: just like when decorating functions,\n\n @f1(arg)\n @f2\n class Foo: pass\n\nis equivalent to\n\n class Foo: pass\n Foo = f1(arg)(f2(Foo))\n\nThe evaluation rules for the decorator expressions are the same as for\nfunction decorators. The result must be a class object, which is then\nbound to the class name.\n\n**Programmer\'s note:** Variables defined in the class definition are\nclass attributes; they are shared by instances. Instance attributes\ncan be set in a method with "self.name = value". Both class and\ninstance attributes are accessible through the notation ""self.name"",\nand an instance attribute hides a class attribute with the same name\nwhen accessed in this way. Class attributes can be used as defaults\nfor instance attributes, but using mutable values there can lead to\nunexpected results. *Descriptors* can be used to create instance\nvariables with different implementation details.\n\nSee also:\n\n **PEP 3115** - Metaclasses in Python 3 **PEP 3129** - Class\n Decorators\n\n-[ Footnotes ]-\n\n[1] The exception is propagated to the invocation stack unless there\n is a "finally" clause which happens to raise another exception.\n That new exception causes the old one to be lost.\n\n[2] Currently, control "flows off the end" except in the case of an\n exception or the execution of a "return", "continue", or "break"\n statement.\n\n[3] A string literal appearing as the first statement in the function\n body is transformed into the function\'s "__doc__" attribute and\n therefore the function\'s *docstring*.\n\n[4] A string literal appearing as the first statement in the class\n body is transformed into the namespace\'s "__doc__" item and\n therefore the class\'s *docstring*.\n', - 'comparisons': '\nComparisons\n***********\n\nUnlike C, all comparison operations in Python have the same priority,\nwhich is lower than that of any arithmetic, shifting or bitwise\noperation. Also unlike C, expressions like "a < b < c" have the\ninterpretation that is conventional in mathematics:\n\n comparison ::= or_expr ( comp_operator or_expr )*\n comp_operator ::= "<" | ">" | "==" | ">=" | "<=" | "!="\n | "is" ["not"] | ["not"] "in"\n\nComparisons yield boolean values: "True" or "False".\n\nComparisons can be chained arbitrarily, e.g., "x < y <= z" is\nequivalent to "x < y and y <= z", except that "y" is evaluated only\nonce (but in both cases "z" is not evaluated at all when "x < y" is\nfound to be false).\n\nFormally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *op1*,\n*op2*, ..., *opN* are comparison operators, then "a op1 b op2 c ... y\nopN z" is equivalent to "a op1 b and b op2 c and ... y opN z", except\nthat each expression is evaluated at most once.\n\nNote that "a op1 b op2 c" doesn\'t imply any kind of comparison between\n*a* and *c*, so that, e.g., "x < y > z" is perfectly legal (though\nperhaps not pretty).\n\nThe operators "<", ">", "==", ">=", "<=", and "!=" compare the values\nof two objects. The objects need not have the same type. If both are\nnumbers, they are converted to a common type. Otherwise, the "==" and\n"!=" operators *always* consider objects of different types to be\nunequal, while the "<", ">", ">=" and "<=" operators raise a\n"TypeError" when comparing objects of different types that do not\nimplement these operators for the given pair of types. You can\ncontrol comparison behavior of objects of non-built-in types by\ndefining rich comparison methods like "__gt__()", described in section\n*Basic customization*.\n\nComparison of objects of the same type depends on the type:\n\n* Numbers are compared arithmetically.\n\n* The values "float(\'NaN\')" and "Decimal(\'NaN\')" are special. The are\n identical to themselves, "x is x" but are not equal to themselves,\n "x != x". Additionally, comparing any value to a not-a-number value\n will return "False". For example, both "3 < float(\'NaN\')" and\n "float(\'NaN\') < 3" will return "False".\n\n* Bytes objects are compared lexicographically using the numeric\n values of their elements.\n\n* Strings are compared lexicographically using the numeric equivalents\n (the result of the built-in function "ord()") of their characters.\n [3] String and bytes object can\'t be compared!\n\n* Tuples and lists are compared lexicographically using comparison of\n corresponding elements. This means that to compare equal, each\n element must compare equal and the two sequences must be of the same\n type and have the same length.\n\n If not equal, the sequences are ordered the same as their first\n differing elements. For example, "[1,2,x] <= [1,2,y]" has the same\n value as "x <= y". If the corresponding element does not exist, the\n shorter sequence is ordered first (for example, "[1,2] < [1,2,3]").\n\n* Mappings (dictionaries) compare equal if and only if they have the\n same "(key, value)" pairs. Order comparisons "(\'<\', \'<=\', \'>=\',\n \'>\')" raise "TypeError".\n\n* Sets and frozensets define comparison operators to mean subset and\n superset tests. Those relations do not define total orderings (the\n two sets "{1,2}" and {2,3} are not equal, nor subsets of one\n another, nor supersets of one another). Accordingly, sets are not\n appropriate arguments for functions which depend on total ordering.\n For example, "min()", "max()", and "sorted()" produce undefined\n results given a list of sets as inputs.\n\n* Most other objects of built-in types compare unequal unless they are\n the same object; the choice whether one object is considered smaller\n or larger than another one is made arbitrarily but consistently\n within one execution of a program.\n\nComparison of objects of the differing types depends on whether either\nof the types provide explicit support for the comparison. Most\nnumeric types can be compared with one another. When cross-type\ncomparison is not supported, the comparison method returns\n"NotImplemented".\n\nThe operators "in" and "not in" test for membership. "x in s"\nevaluates to true if *x* is a member of *s*, and false otherwise. "x\nnot in s" returns the negation of "x in s". All built-in sequences\nand set types support this as well as dictionary, for which "in" tests\nwhether a the dictionary has a given key. For container types such as\nlist, tuple, set, frozenset, dict, or collections.deque, the\nexpression "x in y" is equivalent to "any(x is e or x == e for e in\ny)".\n\nFor the string and bytes types, "x in y" is true if and only if *x* is\na substring of *y*. An equivalent test is "y.find(x) != -1". Empty\nstrings are always considered to be a substring of any other string,\nso """ in "abc"" will return "True".\n\nFor user-defined classes which define the "__contains__()" method, "x\nin y" is true if and only if "y.__contains__(x)" is true.\n\nFor user-defined classes which do not define "__contains__()" but do\ndefine "__iter__()", "x in y" is true if some value "z" with "x == z"\nis produced while iterating over "y". If an exception is raised\nduring the iteration, it is as if "in" raised that exception.\n\nLastly, the old-style iteration protocol is tried: if a class defines\n"__getitem__()", "x in y" is true if and only if there is a non-\nnegative integer index *i* such that "x == y[i]", and all lower\ninteger indices do not raise "IndexError" exception. (If any other\nexception is raised, it is as if "in" raised that exception).\n\nThe operator "not in" is defined to have the inverse true value of\n"in".\n\nThe operators "is" and "is not" test for object identity: "x is y" is\ntrue if and only if *x* and *y* are the same object. "x is not y"\nyields the inverse truth value. [4]\n', - 'compound': '\nCompound statements\n*******************\n\nCompound statements contain (groups of) other statements; they affect\nor control the execution of those other statements in some way. In\ngeneral, compound statements span multiple lines, although in simple\nincarnations a whole compound statement may be contained in one line.\n\nThe "if", "while" and "for" statements implement traditional control\nflow constructs. "try" specifies exception handlers and/or cleanup\ncode for a group of statements, while the "with" statement allows the\nexecution of initialization and finalization code around a block of\ncode. Function and class definitions are also syntactically compound\nstatements.\n\nCompound statements consist of one or more \'clauses.\' A clause\nconsists of a header and a \'suite.\' The clause headers of a\nparticular compound statement are all at the same indentation level.\nEach clause header begins with a uniquely identifying keyword and ends\nwith a colon. A suite is a group of statements controlled by a\nclause. A suite can be one or more semicolon-separated simple\nstatements on the same line as the header, following the header\'s\ncolon, or it can be one or more indented statements on subsequent\nlines. Only the latter form of suite can contain nested compound\nstatements; the following is illegal, mostly because it wouldn\'t be\nclear to which "if" clause a following "else" clause would belong:\n\n if test1: if test2: print(x)\n\nAlso note that the semicolon binds tighter than the colon in this\ncontext, so that in the following example, either all or none of the\n"print()" calls are executed:\n\n if x < y < z: print(x); print(y); print(z)\n\nSummarizing:\n\n compound_stmt ::= if_stmt\n | while_stmt\n | for_stmt\n | try_stmt\n | with_stmt\n | funcdef\n | classdef\n suite ::= stmt_list NEWLINE | NEWLINE INDENT statement+ DEDENT\n statement ::= stmt_list NEWLINE | compound_stmt\n stmt_list ::= simple_stmt (";" simple_stmt)* [";"]\n\nNote that statements always end in a "NEWLINE" possibly followed by a\n"DEDENT". Also note that optional continuation clauses always begin\nwith a keyword that cannot start a statement, thus there are no\nambiguities (the \'dangling "else"\' problem is solved in Python by\nrequiring nested "if" statements to be indented).\n\nThe formatting of the grammar rules in the following sections places\neach clause on a separate line for clarity.\n\n\nThe "if" statement\n==================\n\nThe "if" statement is used for conditional execution:\n\n if_stmt ::= "if" expression ":" suite\n ( "elif" expression ":" suite )*\n ["else" ":" suite]\n\nIt selects exactly one of the suites by evaluating the expressions one\nby one until one is found to be true (see section *Boolean operations*\nfor the definition of true and false); then that suite is executed\n(and no other part of the "if" statement is executed or evaluated).\nIf all expressions are false, the suite of the "else" clause, if\npresent, is executed.\n\n\nThe "while" statement\n=====================\n\nThe "while" statement is used for repeated execution as long as an\nexpression is true:\n\n while_stmt ::= "while" expression ":" suite\n ["else" ":" suite]\n\nThis repeatedly tests the expression and, if it is true, executes the\nfirst suite; if the expression is false (which may be the first time\nit is tested) the suite of the "else" clause, if present, is executed\nand the loop terminates.\n\nA "break" statement executed in the first suite terminates the loop\nwithout executing the "else" clause\'s suite. A "continue" statement\nexecuted in the first suite skips the rest of the suite and goes back\nto testing the expression.\n\n\nThe "for" statement\n===================\n\nThe "for" statement is used to iterate over the elements of a sequence\n(such as a string, tuple or list) or other iterable object:\n\n for_stmt ::= "for" target_list "in" expression_list ":" suite\n ["else" ":" suite]\n\nThe expression list is evaluated once; it should yield an iterable\nobject. An iterator is created for the result of the\n"expression_list". The suite is then executed once for each item\nprovided by the iterator, in the order of ascending indices. Each\nitem in turn is assigned to the target list using the standard rules\nfor assignments (see *Assignment statements*), and then the suite is\nexecuted. When the items are exhausted (which is immediately when the\nsequence is empty or an iterator raises a "StopIteration" exception),\nthe suite in the "else" clause, if present, is executed, and the loop\nterminates.\n\nA "break" statement executed in the first suite terminates the loop\nwithout executing the "else" clause\'s suite. A "continue" statement\nexecuted in the first suite skips the rest of the suite and continues\nwith the next item, or with the "else" clause if there was no next\nitem.\n\nThe suite may assign to the variable(s) in the target list; this does\nnot affect the next item assigned to it.\n\nNames in the target list are not deleted when the loop is finished,\nbut if the sequence is empty, it will not have been assigned to at all\nby the loop. Hint: the built-in function "range()" returns an\niterator of integers suitable to emulate the effect of Pascal\'s "for i\n:= a to b do"; e.g., "list(range(3))" returns the list "[0, 1, 2]".\n\nNote: There is a subtlety when the sequence is being modified by the loop\n (this can only occur for mutable sequences, i.e. lists). An\n internal counter is used to keep track of which item is used next,\n and this is incremented on each iteration. When this counter has\n reached the length of the sequence the loop terminates. This means\n that if the suite deletes the current (or a previous) item from the\n sequence, the next item will be skipped (since it gets the index of\n the current item which has already been treated). Likewise, if the\n suite inserts an item in the sequence before the current item, the\n current item will be treated again the next time through the loop.\n This can lead to nasty bugs that can be avoided by making a\n temporary copy using a slice of the whole sequence, e.g.,\n\n for x in a[:]:\n if x < 0: a.remove(x)\n\n\nThe "try" statement\n===================\n\nThe "try" statement specifies exception handlers and/or cleanup code\nfor a group of statements:\n\n try_stmt ::= try1_stmt | try2_stmt\n try1_stmt ::= "try" ":" suite\n ("except" [expression ["as" target]] ":" suite)+\n ["else" ":" suite]\n ["finally" ":" suite]\n try2_stmt ::= "try" ":" suite\n "finally" ":" suite\n\nThe "except" clause(s) specify one or more exception handlers. When no\nexception occurs in the "try" clause, no exception handler is\nexecuted. When an exception occurs in the "try" suite, a search for an\nexception handler is started. This search inspects the except clauses\nin turn until one is found that matches the exception. An expression-\nless except clause, if present, must be last; it matches any\nexception. For an except clause with an expression, that expression\nis evaluated, and the clause matches the exception if the resulting\nobject is "compatible" with the exception. An object is compatible\nwith an exception if it is the class or a base class of the exception\nobject or a tuple containing an item compatible with the exception.\n\nIf no except clause matches the exception, the search for an exception\nhandler continues in the surrounding code and on the invocation stack.\n[1]\n\nIf the evaluation of an expression in the header of an except clause\nraises an exception, the original search for a handler is canceled and\na search starts for the new exception in the surrounding code and on\nthe call stack (it is treated as if the entire "try" statement raised\nthe exception).\n\nWhen a matching except clause is found, the exception is assigned to\nthe target specified after the "as" keyword in that except clause, if\npresent, and the except clause\'s suite is executed. All except\nclauses must have an executable block. When the end of this block is\nreached, execution continues normally after the entire try statement.\n(This means that if two nested handlers exist for the same exception,\nand the exception occurs in the try clause of the inner handler, the\nouter handler will not handle the exception.)\n\nWhen an exception has been assigned using "as target", it is cleared\nat the end of the except clause. This is as if\n\n except E as N:\n foo\n\nwas translated to\n\n except E as N:\n try:\n foo\n finally:\n del N\n\nThis means the exception must be assigned to a different name to be\nable to refer to it after the except clause. Exceptions are cleared\nbecause with the traceback attached to them, they form a reference\ncycle with the stack frame, keeping all locals in that frame alive\nuntil the next garbage collection occurs.\n\nBefore an except clause\'s suite is executed, details about the\nexception are stored in the "sys" module and can be access via\n"sys.exc_info()". "sys.exc_info()" returns a 3-tuple consisting of the\nexception class, the exception instance and a traceback object (see\nsection *The standard type hierarchy*) identifying the point in the\nprogram where the exception occurred. "sys.exc_info()" values are\nrestored to their previous values (before the call) when returning\nfrom a function that handled an exception.\n\nThe optional "else" clause is executed if and when control flows off\nthe end of the "try" clause. [2] Exceptions in the "else" clause are\nnot handled by the preceding "except" clauses.\n\nIf "finally" is present, it specifies a \'cleanup\' handler. The "try"\nclause is executed, including any "except" and "else" clauses. If an\nexception occurs in any of the clauses and is not handled, the\nexception is temporarily saved. The "finally" clause is executed. If\nthere is a saved exception it is re-raised at the end of the "finally"\nclause. If the "finally" clause raises another exception, the saved\nexception is set as the context of the new exception. If the "finally"\nclause executes a "return" or "break" statement, the saved exception\nis discarded:\n\n >>> def f():\n ... try:\n ... 1/0\n ... finally:\n ... return 42\n ...\n >>> f()\n 42\n\nThe exception information is not available to the program during\nexecution of the "finally" clause.\n\nWhen a "return", "break" or "continue" statement is executed in the\n"try" suite of a "try"..."finally" statement, the "finally" clause is\nalso executed \'on the way out.\' A "continue" statement is illegal in\nthe "finally" clause. (The reason is a problem with the current\nimplementation --- this restriction may be lifted in the future).\n\nThe return value of a function is determined by the last "return"\nstatement executed. Since the "finally" clause always executes, a\n"return" statement executed in the "finally" clause will always be the\nlast one executed:\n\n >>> def foo():\n ... try:\n ... return \'try\'\n ... finally:\n ... return \'finally\'\n ...\n >>> foo()\n \'finally\'\n\nAdditional information on exceptions can be found in section\n*Exceptions*, and information on using the "raise" statement to\ngenerate exceptions may be found in section *The raise statement*.\n\n\nThe "with" statement\n====================\n\nThe "with" statement is used to wrap the execution of a block with\nmethods defined by a context manager (see section *With Statement\nContext Managers*). This allows common "try"..."except"..."finally"\nusage patterns to be encapsulated for convenient reuse.\n\n with_stmt ::= "with" with_item ("," with_item)* ":" suite\n with_item ::= expression ["as" target]\n\nThe execution of the "with" statement with one "item" proceeds as\nfollows:\n\n1. The context expression (the expression given in the "with_item") is\n evaluated to obtain a context manager.\n\n2. The context manager\'s "__exit__()" is loaded for later use.\n\n3. The context manager\'s "__enter__()" method is invoked.\n\n4. If a target was included in the "with" statement, the return value\n from "__enter__()" is assigned to it.\n\n Note: The "with" statement guarantees that if the "__enter__()" method\n returns without an error, then "__exit__()" will always be\n called. Thus, if an error occurs during the assignment to the\n target list, it will be treated the same as an error occurring\n within the suite would be. See step 6 below.\n\n5. The suite is executed.\n\n6. The context manager\'s "__exit__()" method is invoked. If an\n exception caused the suite to be exited, its type, value, and\n traceback are passed as arguments to "__exit__()". Otherwise, three\n "None" arguments are supplied.\n\n If the suite was exited due to an exception, and the return value\n from the "__exit__()" method was false, the exception is reraised.\n If the return value was true, the exception is suppressed, and\n execution continues with the statement following the "with"\n statement.\n\n If the suite was exited for any reason other than an exception, the\n return value from "__exit__()" is ignored, and execution proceeds\n at the normal location for the kind of exit that was taken.\n\nWith more than one item, the context managers are processed as if\nmultiple "with" statements were nested:\n\n with A() as a, B() as b:\n suite\n\nis equivalent to\n\n with A() as a:\n with B() as b:\n suite\n\nChanged in version 3.1: Support for multiple context expressions.\n\nSee also:\n\n **PEP 0343** - The "with" statement\n The specification, background, and examples for the Python\n "with" statement.\n\n\nFunction definitions\n====================\n\nA function definition defines a user-defined function object (see\nsection *The standard type hierarchy*):\n\n funcdef ::= [decorators] "def" funcname "(" [parameter_list] ")" ["->" expression] ":" suite\n decorators ::= decorator+\n decorator ::= "@" dotted_name ["(" [parameter_list [","]] ")"] NEWLINE\n dotted_name ::= identifier ("." identifier)*\n parameter_list ::= (defparameter ",")*\n ( "*" [parameter] ("," defparameter)* ["," "**" parameter]\n | "**" parameter\n | defparameter [","] )\n parameter ::= identifier [":" expression]\n defparameter ::= parameter ["=" expression]\n funcname ::= identifier\n\nA function definition is an executable statement. Its execution binds\nthe function name in the current local namespace to a function object\n(a wrapper around the executable code for the function). This\nfunction object contains a reference to the current global namespace\nas the global namespace to be used when the function is called.\n\nThe function definition does not execute the function body; this gets\nexecuted only when the function is called. [3]\n\nA function definition may be wrapped by one or more *decorator*\nexpressions. Decorator expressions are evaluated when the function is\ndefined, in the scope that contains the function definition. The\nresult must be a callable, which is invoked with the function object\nas the only argument. The returned value is bound to the function name\ninstead of the function object. Multiple decorators are applied in\nnested fashion. For example, the following code\n\n @f1(arg)\n @f2\n def func(): pass\n\nis equivalent to\n\n def func(): pass\n func = f1(arg)(f2(func))\n\nWhen one or more *parameters* have the form *parameter* "="\n*expression*, the function is said to have "default parameter values."\nFor a parameter with a default value, the corresponding *argument* may\nbe omitted from a call, in which case the parameter\'s default value is\nsubstituted. If a parameter has a default value, all following\nparameters up until the ""*"" must also have a default value --- this\nis a syntactic restriction that is not expressed by the grammar.\n\n**Default parameter values are evaluated from left to right when the\nfunction definition is executed.** This means that the expression is\nevaluated once, when the function is defined, and that the same "pre-\ncomputed" value is used for each call. This is especially important\nto understand when a default parameter is a mutable object, such as a\nlist or a dictionary: if the function modifies the object (e.g. by\nappending an item to a list), the default value is in effect modified.\nThis is generally not what was intended. A way around this is to use\n"None" as the default, and explicitly test for it in the body of the\nfunction, e.g.:\n\n def whats_on_the_telly(penguin=None):\n if penguin is None:\n penguin = []\n penguin.append("property of the zoo")\n return penguin\n\nFunction call semantics are described in more detail in section\n*Calls*. A function call always assigns values to all parameters\nmentioned in the parameter list, either from position arguments, from\nkeyword arguments, or from default values. If the form\n""*identifier"" is present, it is initialized to a tuple receiving any\nexcess positional parameters, defaulting to the empty tuple. If the\nform ""**identifier"" is present, it is initialized to a new\ndictionary receiving any excess keyword arguments, defaulting to a new\nempty dictionary. Parameters after ""*"" or ""*identifier"" are\nkeyword-only parameters and may only be passed used keyword arguments.\n\nParameters may have annotations of the form "": expression"" following\nthe parameter name. Any parameter may have an annotation even those\nof the form "*identifier" or "**identifier". Functions may have\n"return" annotation of the form ""-> expression"" after the parameter\nlist. These annotations can be any valid Python expression and are\nevaluated when the function definition is executed. Annotations may\nbe evaluated in a different order than they appear in the source code.\nThe presence of annotations does not change the semantics of a\nfunction. The annotation values are available as values of a\ndictionary keyed by the parameters\' names in the "__annotations__"\nattribute of the function object.\n\nIt is also possible to create anonymous functions (functions not bound\nto a name), for immediate use in expressions. This uses lambda\nexpressions, described in section *Lambdas*. Note that the lambda\nexpression is merely a shorthand for a simplified function definition;\na function defined in a ""def"" statement can be passed around or\nassigned to another name just like a function defined by a lambda\nexpression. The ""def"" form is actually more powerful since it\nallows the execution of multiple statements and annotations.\n\n**Programmer\'s note:** Functions are first-class objects. A ""def""\nstatement executed inside a function definition defines a local\nfunction that can be returned or passed around. Free variables used\nin the nested function can access the local variables of the function\ncontaining the def. See section *Naming and binding* for details.\n\nSee also:\n\n **PEP 3107** - Function Annotations\n The original specification for function annotations.\n\n\nClass definitions\n=================\n\nA class definition defines a class object (see section *The standard\ntype hierarchy*):\n\n classdef ::= [decorators] "class" classname [inheritance] ":" suite\n inheritance ::= "(" [parameter_list] ")"\n classname ::= identifier\n\nA class definition is an executable statement. The inheritance list\nusually gives a list of base classes (see *Customizing class creation*\nfor more advanced uses), so each item in the list should evaluate to a\nclass object which allows subclassing. Classes without an inheritance\nlist inherit, by default, from the base class "object"; hence,\n\n class Foo:\n pass\n\nis equivalent to\n\n class Foo(object):\n pass\n\nThe class\'s suite is then executed in a new execution frame (see\n*Naming and binding*), using a newly created local namespace and the\noriginal global namespace. (Usually, the suite contains mostly\nfunction definitions.) When the class\'s suite finishes execution, its\nexecution frame is discarded but its local namespace is saved. [4] A\nclass object is then created using the inheritance list for the base\nclasses and the saved local namespace for the attribute dictionary.\nThe class name is bound to this class object in the original local\nnamespace.\n\nClass creation can be customized heavily using *metaclasses*.\n\nClasses can also be decorated: just like when decorating functions,\n\n @f1(arg)\n @f2\n class Foo: pass\n\nis equivalent to\n\n class Foo: pass\n Foo = f1(arg)(f2(Foo))\n\nThe evaluation rules for the decorator expressions are the same as for\nfunction decorators. The result must be a class object, which is then\nbound to the class name.\n\n**Programmer\'s note:** Variables defined in the class definition are\nclass attributes; they are shared by instances. Instance attributes\ncan be set in a method with "self.name = value". Both class and\ninstance attributes are accessible through the notation ""self.name"",\nand an instance attribute hides a class attribute with the same name\nwhen accessed in this way. Class attributes can be used as defaults\nfor instance attributes, but using mutable values there can lead to\nunexpected results. *Descriptors* can be used to create instance\nvariables with different implementation details.\n\nSee also:\n\n **PEP 3115** - Metaclasses in Python 3 **PEP 3129** - Class\n Decorators\n\n-[ Footnotes ]-\n\n[1] The exception is propagated to the invocation stack unless there\n is a "finally" clause which happens to raise another exception.\n That new exception causes the old one to be lost.\n\n[2] Currently, control "flows off the end" except in the case of an\n exception or the execution of a "return", "continue", or "break"\n statement.\n\n[3] A string literal appearing as the first statement in the function\n body is transformed into the function\'s "__doc__" attribute and\n therefore the function\'s *docstring*.\n\n[4] A string literal appearing as the first statement in the class\n body is transformed into the namespace\'s "__doc__" item and\n therefore the class\'s *docstring*.\n', - 'context-managers': '\nWith Statement Context Managers\n*******************************\n\nA *context manager* is an object that defines the runtime context to\nbe established when executing a "with" statement. The context manager\nhandles the entry into, and the exit from, the desired runtime context\nfor the execution of the block of code. Context managers are normally\ninvoked using the "with" statement (described in section *The with\nstatement*), but can also be used by directly invoking their methods.\n\nTypical uses of context managers include saving and restoring various\nkinds of global state, locking and unlocking resources, closing opened\nfiles, etc.\n\nFor more information on context managers, see *Context Manager Types*.\n\nobject.__enter__(self)\n\n Enter the runtime context related to this object. The "with"\n statement will bind this method\'s return value to the target(s)\n specified in the "as" clause of the statement, if any.\n\nobject.__exit__(self, exc_type, exc_value, traceback)\n\n Exit the runtime context related to this object. The parameters\n describe the exception that caused the context to be exited. If the\n context was exited without an exception, all three arguments will\n be "None".\n\n If an exception is supplied, and the method wishes to suppress the\n exception (i.e., prevent it from being propagated), it should\n return a true value. Otherwise, the exception will be processed\n normally upon exit from this method.\n\n Note that "__exit__()" methods should not reraise the passed-in\n exception; this is the caller\'s responsibility.\n\nSee also:\n\n **PEP 0343** - The "with" statement\n The specification, background, and examples for the Python\n "with" statement.\n', + 'class': '\nClass definitions\n*****************\n\nA class definition defines a class object (see section *The standard\ntype hierarchy*):\n\n classdef ::= [decorators] "class" classname [inheritance] ":" suite\n inheritance ::= "(" [parameter_list] ")"\n classname ::= identifier\n\nA class definition is an executable statement. The inheritance list\nusually gives a list of base classes (see *Customizing class creation*\nfor more advanced uses), so each item in the list should evaluate to a\nclass object which allows subclassing. Classes without an inheritance\nlist inherit, by default, from the base class "object"; hence,\n\n class Foo:\n pass\n\nis equivalent to\n\n class Foo(object):\n pass\n\nThe class\'s suite is then executed in a new execution frame (see\n*Naming and binding*), using a newly created local namespace and the\noriginal global namespace. (Usually, the suite contains mostly\nfunction definitions.) When the class\'s suite finishes execution, its\nexecution frame is discarded but its local namespace is saved. [4] A\nclass object is then created using the inheritance list for the base\nclasses and the saved local namespace for the attribute dictionary.\nThe class name is bound to this class object in the original local\nnamespace.\n\nClass creation can be customized heavily using *metaclasses*.\n\nClasses can also be decorated: just like when decorating functions,\n\n @f1(arg)\n @f2\n class Foo: pass\n\nis equivalent to\n\n class Foo: pass\n Foo = f1(arg)(f2(Foo))\n\nThe evaluation rules for the decorator expressions are the same as for\nfunction decorators. The result must be a class object, which is then\nbound to the class name.\n\n**Programmer\'s note:** Variables defined in the class definition are\nclass attributes; they are shared by instances. Instance attributes\ncan be set in a method with "self.name = value". Both class and\ninstance attributes are accessible through the notation ""self.name"",\nand an instance attribute hides a class attribute with the same name\nwhen accessed in this way. Class attributes can be used as defaults\nfor instance attributes, but using mutable values there can lead to\nunexpected results. *Descriptors* can be used to create instance\nvariables with different implementation details.\n\nSee also: **PEP 3115** - Metaclasses in Python 3 **PEP 3129** -\n Class Decorators\n\n-[ Footnotes ]-\n\n[1] The exception is propagated to the invocation stack unless\n there is a "finally" clause which happens to raise another\n exception. That new exception causes the old one to be lost.\n\n[2] Currently, control "flows off the end" except in the case of\n an exception or the execution of a "return", "continue", or\n "break" statement.\n\n[3] A string literal appearing as the first statement in the\n function body is transformed into the function\'s "__doc__"\n attribute and therefore the function\'s *docstring*.\n\n[4] A string literal appearing as the first statement in the class\n body is transformed into the namespace\'s "__doc__" item and\n therefore the class\'s *docstring*.\n', + 'comparisons': '\nComparisons\n***********\n\nUnlike C, all comparison operations in Python have the same priority,\nwhich is lower than that of any arithmetic, shifting or bitwise\noperation. Also unlike C, expressions like "a < b < c" have the\ninterpretation that is conventional in mathematics:\n\n comparison ::= or_expr ( comp_operator or_expr )*\n comp_operator ::= "<" | ">" | "==" | ">=" | "<=" | "!="\n | "is" ["not"] | ["not"] "in"\n\nComparisons yield boolean values: "True" or "False".\n\nComparisons can be chained arbitrarily, e.g., "x < y <= z" is\nequivalent to "x < y and y <= z", except that "y" is evaluated only\nonce (but in both cases "z" is not evaluated at all when "x < y" is\nfound to be false).\n\nFormally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *op1*,\n*op2*, ..., *opN* are comparison operators, then "a op1 b op2 c ... y\nopN z" is equivalent to "a op1 b and b op2 c and ... y opN z", except\nthat each expression is evaluated at most once.\n\nNote that "a op1 b op2 c" doesn\'t imply any kind of comparison between\n*a* and *c*, so that, e.g., "x < y > z" is perfectly legal (though\nperhaps not pretty).\n\nThe operators "<", ">", "==", ">=", "<=", and "!=" compare the values\nof two objects. The objects need not have the same type. If both are\nnumbers, they are converted to a common type. Otherwise, the "==" and\n"!=" operators *always* consider objects of different types to be\nunequal, while the "<", ">", ">=" and "<=" operators raise a\n"TypeError" when comparing objects of different types that do not\nimplement these operators for the given pair of types. You can\ncontrol comparison behavior of objects of non-built-in types by\ndefining rich comparison methods like "__gt__()", described in section\n*Basic customization*.\n\nComparison of objects of the same type depends on the type:\n\n* Numbers are compared arithmetically.\n\n* The values "float(\'NaN\')" and "Decimal(\'NaN\')" are special. The\n are identical to themselves, "x is x" but are not equal to\n themselves, "x != x". Additionally, comparing any value to a\n not-a-number value will return "False". For example, both "3 <\n float(\'NaN\')" and "float(\'NaN\') < 3" will return "False".\n\n* Bytes objects are compared lexicographically using the numeric\n values of their elements.\n\n* Strings are compared lexicographically using the numeric\n equivalents (the result of the built-in function "ord()") of their\n characters. [3] String and bytes object can\'t be compared!\n\n* Tuples and lists are compared lexicographically using comparison\n of corresponding elements. This means that to compare equal, each\n element must compare equal and the two sequences must be of the same\n type and have the same length.\n\n If not equal, the sequences are ordered the same as their first\n differing elements. For example, "[1,2,x] <= [1,2,y]" has the same\n value as "x <= y". If the corresponding element does not exist, the\n shorter sequence is ordered first (for example, "[1,2] < [1,2,3]").\n\n* Mappings (dictionaries) compare equal if and only if they have the\n same "(key, value)" pairs. Order comparisons "(\'<\', \'<=\', \'>=\',\n \'>\')" raise "TypeError".\n\n* Sets and frozensets define comparison operators to mean subset and\n superset tests. Those relations do not define total orderings (the\n two sets "{1,2}" and {2,3} are not equal, nor subsets of one\n another, nor supersets of one another). Accordingly, sets are not\n appropriate arguments for functions which depend on total ordering.\n For example, "min()", "max()", and "sorted()" produce undefined\n results given a list of sets as inputs.\n\n* Most other objects of built-in types compare unequal unless they\n are the same object; the choice whether one object is considered\n smaller or larger than another one is made arbitrarily but\n consistently within one execution of a program.\n\nComparison of objects of the differing types depends on whether either\nof the types provide explicit support for the comparison. Most\nnumeric types can be compared with one another. When cross-type\ncomparison is not supported, the comparison method returns\n"NotImplemented".\n\nThe operators "in" and "not in" test for membership. "x in s"\nevaluates to true if *x* is a member of *s*, and false otherwise. "x\nnot in s" returns the negation of "x in s". All built-in sequences\nand set types support this as well as dictionary, for which "in" tests\nwhether a the dictionary has a given key. For container types such as\nlist, tuple, set, frozenset, dict, or collections.deque, the\nexpression "x in y" is equivalent to "any(x is e or x == e for e in\ny)".\n\nFor the string and bytes types, "x in y" is true if and only if *x* is\na substring of *y*. An equivalent test is "y.find(x) != -1". Empty\nstrings are always considered to be a substring of any other string,\nso """ in "abc"" will return "True".\n\nFor user-defined classes which define the "__contains__()" method, "x\nin y" is true if and only if "y.__contains__(x)" is true.\n\nFor user-defined classes which do not define "__contains__()" but do\ndefine "__iter__()", "x in y" is true if some value "z" with "x == z"\nis produced while iterating over "y". If an exception is raised\nduring the iteration, it is as if "in" raised that exception.\n\nLastly, the old-style iteration protocol is tried: if a class defines\n"__getitem__()", "x in y" is true if and only if there is a non-\nnegative integer index *i* such that "x == y[i]", and all lower\ninteger indices do not raise "IndexError" exception. (If any other\nexception is raised, it is as if "in" raised that exception).\n\nThe operator "not in" is defined to have the inverse true value of\n"in".\n\nThe operators "is" and "is not" test for object identity: "x is y" is\ntrue if and only if *x* and *y* are the same object. "x is not y"\nyields the inverse truth value. [4]\n', + 'compound': '\nCompound statements\n*******************\n\nCompound statements contain (groups of) other statements; they affect\nor control the execution of those other statements in some way. In\ngeneral, compound statements span multiple lines, although in simple\nincarnations a whole compound statement may be contained in one line.\n\nThe "if", "while" and "for" statements implement traditional control\nflow constructs. "try" specifies exception handlers and/or cleanup\ncode for a group of statements, while the "with" statement allows the\nexecution of initialization and finalization code around a block of\ncode. Function and class definitions are also syntactically compound\nstatements.\n\nCompound statements consist of one or more \'clauses.\' A clause\nconsists of a header and a \'suite.\' The clause headers of a\nparticular compound statement are all at the same indentation level.\nEach clause header begins with a uniquely identifying keyword and ends\nwith a colon. A suite is a group of statements controlled by a\nclause. A suite can be one or more semicolon-separated simple\nstatements on the same line as the header, following the header\'s\ncolon, or it can be one or more indented statements on subsequent\nlines. Only the latter form of suite can contain nested compound\nstatements; the following is illegal, mostly because it wouldn\'t be\nclear to which "if" clause a following "else" clause would belong:\n\n if test1: if test2: print(x)\n\nAlso note that the semicolon binds tighter than the colon in this\ncontext, so that in the following example, either all or none of the\n"print()" calls are executed:\n\n if x < y < z: print(x); print(y); print(z)\n\nSummarizing:\n\n compound_stmt ::= if_stmt\n | while_stmt\n | for_stmt\n | try_stmt\n | with_stmt\n | funcdef\n | classdef\n suite ::= stmt_list NEWLINE | NEWLINE INDENT statement+ DEDENT\n statement ::= stmt_list NEWLINE | compound_stmt\n stmt_list ::= simple_stmt (";" simple_stmt)* [";"]\n\nNote that statements always end in a "NEWLINE" possibly followed by a\n"DEDENT". Also note that optional continuation clauses always begin\nwith a keyword that cannot start a statement, thus there are no\nambiguities (the \'dangling "else"\' problem is solved in Python by\nrequiring nested "if" statements to be indented).\n\nThe formatting of the grammar rules in the following sections places\neach clause on a separate line for clarity.\n\n\nThe "if" statement\n==================\n\nThe "if" statement is used for conditional execution:\n\n if_stmt ::= "if" expression ":" suite\n ( "elif" expression ":" suite )*\n ["else" ":" suite]\n\nIt selects exactly one of the suites by evaluating the expressions one\nby one until one is found to be true (see section *Boolean operations*\nfor the definition of true and false); then that suite is executed\n(and no other part of the "if" statement is executed or evaluated).\nIf all expressions are false, the suite of the "else" clause, if\npresent, is executed.\n\n\nThe "while" statement\n=====================\n\nThe "while" statement is used for repeated execution as long as an\nexpression is true:\n\n while_stmt ::= "while" expression ":" suite\n ["else" ":" suite]\n\nThis repeatedly tests the expression and, if it is true, executes the\nfirst suite; if the expression is false (which may be the first time\nit is tested) the suite of the "else" clause, if present, is executed\nand the loop terminates.\n\nA "break" statement executed in the first suite terminates the loop\nwithout executing the "else" clause\'s suite. A "continue" statement\nexecuted in the first suite skips the rest of the suite and goes back\nto testing the expression.\n\n\nThe "for" statement\n===================\n\nThe "for" statement is used to iterate over the elements of a sequence\n(such as a string, tuple or list) or other iterable object:\n\n for_stmt ::= "for" target_list "in" expression_list ":" suite\n ["else" ":" suite]\n\nThe expression list is evaluated once; it should yield an iterable\nobject. An iterator is created for the result of the\n"expression_list". The suite is then executed once for each item\nprovided by the iterator, in the order of ascending indices. Each\nitem in turn is assigned to the target list using the standard rules\nfor assignments (see *Assignment statements*), and then the suite is\nexecuted. When the items are exhausted (which is immediately when the\nsequence is empty or an iterator raises a "StopIteration" exception),\nthe suite in the "else" clause, if present, is executed, and the loop\nterminates.\n\nA "break" statement executed in the first suite terminates the loop\nwithout executing the "else" clause\'s suite. A "continue" statement\nexecuted in the first suite skips the rest of the suite and continues\nwith the next item, or with the "else" clause if there was no next\nitem.\n\nThe suite may assign to the variable(s) in the target list; this does\nnot affect the next item assigned to it.\n\nNames in the target list are not deleted when the loop is finished,\nbut if the sequence is empty, it will not have been assigned to at all\nby the loop. Hint: the built-in function "range()" returns an\niterator of integers suitable to emulate the effect of Pascal\'s "for i\n:= a to b do"; e.g., "list(range(3))" returns the list "[0, 1, 2]".\n\nNote: There is a subtlety when the sequence is being modified by the\n loop (this can only occur for mutable sequences, i.e. lists). An\n internal counter is used to keep track of which item is used next,\n and this is incremented on each iteration. When this counter has\n reached the length of the sequence the loop terminates. This means\n that if the suite deletes the current (or a previous) item from the\n sequence, the next item will be skipped (since it gets the index of\n the current item which has already been treated). Likewise, if the\n suite inserts an item in the sequence before the current item, the\n current item will be treated again the next time through the loop.\n This can lead to nasty bugs that can be avoided by making a\n temporary copy using a slice of the whole sequence, e.g.,\n\n for x in a[:]:\n if x < 0: a.remove(x)\n\n\nThe "try" statement\n===================\n\nThe "try" statement specifies exception handlers and/or cleanup code\nfor a group of statements:\n\n try_stmt ::= try1_stmt | try2_stmt\n try1_stmt ::= "try" ":" suite\n ("except" [expression ["as" target]] ":" suite)+\n ["else" ":" suite]\n ["finally" ":" suite]\n try2_stmt ::= "try" ":" suite\n "finally" ":" suite\n\nThe "except" clause(s) specify one or more exception handlers. When no\nexception occurs in the "try" clause, no exception handler is\nexecuted. When an exception occurs in the "try" suite, a search for an\nexception handler is started. This search inspects the except clauses\nin turn until one is found that matches the exception. An expression-\nless except clause, if present, must be last; it matches any\nexception. For an except clause with an expression, that expression\nis evaluated, and the clause matches the exception if the resulting\nobject is "compatible" with the exception. An object is compatible\nwith an exception if it is the class or a base class of the exception\nobject or a tuple containing an item compatible with the exception.\n\nIf no except clause matches the exception, the search for an exception\nhandler continues in the surrounding code and on the invocation stack.\n[1]\n\nIf the evaluation of an expression in the header of an except clause\nraises an exception, the original search for a handler is canceled and\na search starts for the new exception in the surrounding code and on\nthe call stack (it is treated as if the entire "try" statement raised\nthe exception).\n\nWhen a matching except clause is found, the exception is assigned to\nthe target specified after the "as" keyword in that except clause, if\npresent, and the except clause\'s suite is executed. All except\nclauses must have an executable block. When the end of this block is\nreached, execution continues normally after the entire try statement.\n(This means that if two nested handlers exist for the same exception,\nand the exception occurs in the try clause of the inner handler, the\nouter handler will not handle the exception.)\n\nWhen an exception has been assigned using "as target", it is cleared\nat the end of the except clause. This is as if\n\n except E as N:\n foo\n\nwas translated to\n\n except E as N:\n try:\n foo\n finally:\n del N\n\nThis means the exception must be assigned to a different name to be\nable to refer to it after the except clause. Exceptions are cleared\nbecause with the traceback attached to them, they form a reference\ncycle with the stack frame, keeping all locals in that frame alive\nuntil the next garbage collection occurs.\n\nBefore an except clause\'s suite is executed, details about the\nexception are stored in the "sys" module and can be access via\n"sys.exc_info()". "sys.exc_info()" returns a 3-tuple consisting of the\nexception class, the exception instance and a traceback object (see\nsection *The standard type hierarchy*) identifying the point in the\nprogram where the exception occurred. "sys.exc_info()" values are\nrestored to their previous values (before the call) when returning\nfrom a function that handled an exception.\n\nThe optional "else" clause is executed if and when control flows off\nthe end of the "try" clause. [2] Exceptions in the "else" clause are\nnot handled by the preceding "except" clauses.\n\nIf "finally" is present, it specifies a \'cleanup\' handler. The "try"\nclause is executed, including any "except" and "else" clauses. If an\nexception occurs in any of the clauses and is not handled, the\nexception is temporarily saved. The "finally" clause is executed. If\nthere is a saved exception it is re-raised at the end of the "finally"\nclause. If the "finally" clause raises another exception, the saved\nexception is set as the context of the new exception. If the "finally"\nclause executes a "return" or "break" statement, the saved exception\nis discarded:\n\n def f():\n try:\n 1/0\n finally:\n return 42\n\n >>> f()\n 42\n\nThe exception information is not available to the program during\nexecution of the "finally" clause.\n\nWhen a "return", "break" or "continue" statement is executed in the\n"try" suite of a "try"..."finally" statement, the "finally" clause is\nalso executed \'on the way out.\' A "continue" statement is illegal in\nthe "finally" clause. (The reason is a problem with the current\nimplementation --- this restriction may be lifted in the future).\n\nAdditional information on exceptions can be found in section\n*Exceptions*, and information on using the "raise" statement to\ngenerate exceptions may be found in section *The raise statement*.\n\n\nThe "with" statement\n====================\n\nThe "with" statement is used to wrap the execution of a block with\nmethods defined by a context manager (see section *With Statement\nContext Managers*). This allows common "try"..."except"..."finally"\nusage patterns to be encapsulated for convenient reuse.\n\n with_stmt ::= "with" with_item ("," with_item)* ":" suite\n with_item ::= expression ["as" target]\n\nThe execution of the "with" statement with one "item" proceeds as\nfollows:\n\n1. The context expression (the expression given in the "with_item")\n is evaluated to obtain a context manager.\n\n2. The context manager\'s "__exit__()" is loaded for later use.\n\n3. The context manager\'s "__enter__()" method is invoked.\n\n4. If a target was included in the "with" statement, the return\n value from "__enter__()" is assigned to it.\n\n Note: The "with" statement guarantees that if the "__enter__()"\n method returns without an error, then "__exit__()" will always be\n called. Thus, if an error occurs during the assignment to the\n target list, it will be treated the same as an error occurring\n within the suite would be. See step 6 below.\n\n5. The suite is executed.\n\n6. The context manager\'s "__exit__()" method is invoked. If an\n exception caused the suite to be exited, its type, value, and\n traceback are passed as arguments to "__exit__()". Otherwise, three\n "None" arguments are supplied.\n\n If the suite was exited due to an exception, and the return value\n from the "__exit__()" method was false, the exception is reraised.\n If the return value was true, the exception is suppressed, and\n execution continues with the statement following the "with"\n statement.\n\n If the suite was exited for any reason other than an exception, the\n return value from "__exit__()" is ignored, and execution proceeds\n at the normal location for the kind of exit that was taken.\n\nWith more than one item, the context managers are processed as if\nmultiple "with" statements were nested:\n\n with A() as a, B() as b:\n suite\n\nis equivalent to\n\n with A() as a:\n with B() as b:\n suite\n\nChanged in version 3.1: Support for multiple context expressions.\n\nSee also: **PEP 0343** - The "with" statement\n\n The specification, background, and examples for the Python "with"\n statement.\n\n\nFunction definitions\n====================\n\nA function definition defines a user-defined function object (see\nsection *The standard type hierarchy*):\n\n funcdef ::= [decorators] "def" funcname "(" [parameter_list] ")" ["->" expression] ":" suite\n decorators ::= decorator+\n decorator ::= "@" dotted_name ["(" [parameter_list [","]] ")"] NEWLINE\n dotted_name ::= identifier ("." identifier)*\n parameter_list ::= (defparameter ",")*\n ( "*" [parameter] ("," defparameter)* ["," "**" parameter]\n | "**" parameter\n | defparameter [","] )\n parameter ::= identifier [":" expression]\n defparameter ::= parameter ["=" expression]\n funcname ::= identifier\n\nA function definition is an executable statement. Its execution binds\nthe function name in the current local namespace to a function object\n(a wrapper around the executable code for the function). This\nfunction object contains a reference to the current global namespace\nas the global namespace to be used when the function is called.\n\nThe function definition does not execute the function body; this gets\nexecuted only when the function is called. [3]\n\nA function definition may be wrapped by one or more *decorator*\nexpressions. Decorator expressions are evaluated when the function is\ndefined, in the scope that contains the function definition. The\nresult must be a callable, which is invoked with the function object\nas the only argument. The returned value is bound to the function name\ninstead of the function object. Multiple decorators are applied in\nnested fashion. For example, the following code\n\n @f1(arg)\n @f2\n def func(): pass\n\nis equivalent to\n\n def func(): pass\n func = f1(arg)(f2(func))\n\nWhen one or more *parameters* have the form *parameter* "="\n*expression*, the function is said to have "default parameter values."\nFor a parameter with a default value, the corresponding *argument* may\nbe omitted from a call, in which case the parameter\'s default value is\nsubstituted. If a parameter has a default value, all following\nparameters up until the ""*"" must also have a default value --- this\nis a syntactic restriction that is not expressed by the grammar.\n\n**Default parameter values are evaluated from left to right when the\nfunction definition is executed.** This means that the expression is\nevaluated once, when the function is defined, and that the same "pre-\ncomputed" value is used for each call. This is especially important\nto understand when a default parameter is a mutable object, such as a\nlist or a dictionary: if the function modifies the object (e.g. by\nappending an item to a list), the default value is in effect modified.\nThis is generally not what was intended. A way around this is to use\n"None" as the default, and explicitly test for it in the body of the\nfunction, e.g.:\n\n def whats_on_the_telly(penguin=None):\n if penguin is None:\n penguin = []\n penguin.append("property of the zoo")\n return penguin\n\nFunction call semantics are described in more detail in section\n*Calls*. A function call always assigns values to all parameters\nmentioned in the parameter list, either from position arguments, from\nkeyword arguments, or from default values. If the form\n""*identifier"" is present, it is initialized to a tuple receiving any\nexcess positional parameters, defaulting to the empty tuple. If the\nform ""**identifier"" is present, it is initialized to a new\ndictionary receiving any excess keyword arguments, defaulting to a new\nempty dictionary. Parameters after ""*"" or ""*identifier"" are\nkeyword-only parameters and may only be passed used keyword arguments.\n\nParameters may have annotations of the form "": expression"" following\nthe parameter name. Any parameter may have an annotation even those\nof the form "*identifier" or "**identifier". Functions may have\n"return" annotation of the form ""-> expression"" after the parameter\nlist. These annotations can be any valid Python expression and are\nevaluated when the function definition is executed. Annotations may\nbe evaluated in a different order than they appear in the source code.\nThe presence of annotations does not change the semantics of a\nfunction. The annotation values are available as values of a\ndictionary keyed by the parameters\' names in the "__annotations__"\nattribute of the function object.\n\nIt is also possible to create anonymous functions (functions not bound\nto a name), for immediate use in expressions. This uses lambda\nexpressions, described in section *Lambdas*. Note that the lambda\nexpression is merely a shorthand for a simplified function definition;\na function defined in a ""def"" statement can be passed around or\nassigned to another name just like a function defined by a lambda\nexpression. The ""def"" form is actually more powerful since it\nallows the execution of multiple statements and annotations.\n\n**Programmer\'s note:** Functions are first-class objects. A ""def""\nstatement executed inside a function definition defines a local\nfunction that can be returned or passed around. Free variables used\nin the nested function can access the local variables of the function\ncontaining the def. See section *Naming and binding* for details.\n\nSee also: **PEP 3107** - Function Annotations\n\n The original specification for function annotations.\n\n\nClass definitions\n=================\n\nA class definition defines a class object (see section *The standard\ntype hierarchy*):\n\n classdef ::= [decorators] "class" classname [inheritance] ":" suite\n inheritance ::= "(" [parameter_list] ")"\n classname ::= identifier\n\nA class definition is an executable statement. The inheritance list\nusually gives a list of base classes (see *Customizing class creation*\nfor more advanced uses), so each item in the list should evaluate to a\nclass object which allows subclassing. Classes without an inheritance\nlist inherit, by default, from the base class "object"; hence,\n\n class Foo:\n pass\n\nis equivalent to\n\n class Foo(object):\n pass\n\nThe class\'s suite is then executed in a new execution frame (see\n*Naming and binding*), using a newly created local namespace and the\noriginal global namespace. (Usually, the suite contains mostly\nfunction definitions.) When the class\'s suite finishes execution, its\nexecution frame is discarded but its local namespace is saved. [4] A\nclass object is then created using the inheritance list for the base\nclasses and the saved local namespace for the attribute dictionary.\nThe class name is bound to this class object in the original local\nnamespace.\n\nClass creation can be customized heavily using *metaclasses*.\n\nClasses can also be decorated: just like when decorating functions,\n\n @f1(arg)\n @f2\n class Foo: pass\n\nis equivalent to\n\n class Foo: pass\n Foo = f1(arg)(f2(Foo))\n\nThe evaluation rules for the decorator expressions are the same as for\nfunction decorators. The result must be a class object, which is then\nbound to the class name.\n\n**Programmer\'s note:** Variables defined in the class definition are\nclass attributes; they are shared by instances. Instance attributes\ncan be set in a method with "self.name = value". Both class and\ninstance attributes are accessible through the notation ""self.name"",\nand an instance attribute hides a class attribute with the same name\nwhen accessed in this way. Class attributes can be used as defaults\nfor instance attributes, but using mutable values there can lead to\nunexpected results. *Descriptors* can be used to create instance\nvariables with different implementation details.\n\nSee also: **PEP 3115** - Metaclasses in Python 3 **PEP 3129** -\n Class Decorators\n\n-[ Footnotes ]-\n\n[1] The exception is propagated to the invocation stack unless\n there is a "finally" clause which happens to raise another\n exception. That new exception causes the old one to be lost.\n\n[2] Currently, control "flows off the end" except in the case of\n an exception or the execution of a "return", "continue", or\n "break" statement.\n\n[3] A string literal appearing as the first statement in the\n function body is transformed into the function\'s "__doc__"\n attribute and therefore the function\'s *docstring*.\n\n[4] A string literal appearing as the first statement in the class\n body is transformed into the namespace\'s "__doc__" item and\n therefore the class\'s *docstring*.\n', + 'context-managers': '\nWith Statement Context Managers\n*******************************\n\nA *context manager* is an object that defines the runtime context to\nbe established when executing a "with" statement. The context manager\nhandles the entry into, and the exit from, the desired runtime context\nfor the execution of the block of code. Context managers are normally\ninvoked using the "with" statement (described in section *The with\nstatement*), but can also be used by directly invoking their methods.\n\nTypical uses of context managers include saving and restoring various\nkinds of global state, locking and unlocking resources, closing opened\nfiles, etc.\n\nFor more information on context managers, see *Context Manager Types*.\n\nobject.__enter__(self)\n\n Enter the runtime context related to this object. The "with"\n statement will bind this method\'s return value to the target(s)\n specified in the "as" clause of the statement, if any.\n\nobject.__exit__(self, exc_type, exc_value, traceback)\n\n Exit the runtime context related to this object. The parameters\n describe the exception that caused the context to be exited. If the\n context was exited without an exception, all three arguments will\n be "None".\n\n If an exception is supplied, and the method wishes to suppress the\n exception (i.e., prevent it from being propagated), it should\n return a true value. Otherwise, the exception will be processed\n normally upon exit from this method.\n\n Note that "__exit__()" methods should not reraise the passed-in\n exception; this is the caller\'s responsibility.\n\nSee also: **PEP 0343** - The "with" statement\n\n The specification, background, and examples for the Python "with"\n statement.\n', 'continue': '\nThe "continue" statement\n************************\n\n continue_stmt ::= "continue"\n\n"continue" may only occur syntactically nested in a "for" or "while"\nloop, but not nested in a function or class definition or "finally"\nclause within that loop. It continues with the next cycle of the\nnearest enclosing loop.\n\nWhen "continue" passes control out of a "try" statement with a\n"finally" clause, that "finally" clause is executed before really\nstarting the next loop cycle.\n', - 'conversions': '\nArithmetic conversions\n**********************\n\nWhen a description of an arithmetic operator below uses the phrase\n"the numeric arguments are converted to a common type," this means\nthat the operator implementation for built-in types works that way:\n\n* If either argument is a complex number, the other is converted to\n complex;\n\n* otherwise, if either argument is a floating point number, the other\n is converted to floating point;\n\n* otherwise, both must be integers and no conversion is necessary.\n\nSome additional rules apply for certain operators (e.g., a string left\nargument to the \'%\' operator). Extensions must define their own\nconversion behavior.\n', - 'customization': '\nBasic customization\n*******************\n\nobject.__new__(cls[, ...])\n\n Called to create a new instance of class *cls*. "__new__()" is a\n static method (special-cased so you need not declare it as such)\n that takes the class of which an instance was requested as its\n first argument. The remaining arguments are those passed to the\n object constructor expression (the call to the class). The return\n value of "__new__()" should be the new object instance (usually an\n instance of *cls*).\n\n Typical implementations create a new instance of the class by\n invoking the superclass\'s "__new__()" method using\n "super(currentclass, cls).__new__(cls[, ...])" with appropriate\n arguments and then modifying the newly-created instance as\n necessary before returning it.\n\n If "__new__()" returns an instance of *cls*, then the new\n instance\'s "__init__()" method will be invoked like\n "__init__(self[, ...])", where *self* is the new instance and the\n remaining arguments are the same as were passed to "__new__()".\n\n If "__new__()" does not return an instance of *cls*, then the new\n instance\'s "__init__()" method will not be invoked.\n\n "__new__()" is intended mainly to allow subclasses of immutable\n types (like int, str, or tuple) to customize instance creation. It\n is also commonly overridden in custom metaclasses in order to\n customize class creation.\n\nobject.__init__(self[, ...])\n\n Called when the instance is created. The arguments are those\n passed to the class constructor expression. If a base class has an\n "__init__()" method, the derived class\'s "__init__()" method, if\n any, must explicitly call it to ensure proper initialization of the\n base class part of the instance; for example:\n "BaseClass.__init__(self, [args...])". As a special constraint on\n constructors, no value may be returned; doing so will cause a\n "TypeError" to be raised at runtime.\n\nobject.__del__(self)\n\n Called when the instance is about to be destroyed. This is also\n called a destructor. If a base class has a "__del__()" method, the\n derived class\'s "__del__()" method, if any, must explicitly call it\n to ensure proper deletion of the base class part of the instance.\n Note that it is possible (though not recommended!) for the\n "__del__()" method to postpone destruction of the instance by\n creating a new reference to it. It may then be called at a later\n time when this new reference is deleted. It is not guaranteed that\n "__del__()" methods are called for objects that still exist when\n the interpreter exits.\n\n Note: "del x" doesn\'t directly call "x.__del__()" --- the former\n decrements the reference count for "x" by one, and the latter is\n only called when "x"\'s reference count reaches zero. Some common\n situations that may prevent the reference count of an object from\n going to zero include: circular references between objects (e.g.,\n a doubly-linked list or a tree data structure with parent and\n child pointers); a reference to the object on the stack frame of\n a function that caught an exception (the traceback stored in\n "sys.exc_info()[2]" keeps the stack frame alive); or a reference\n to the object on the stack frame that raised an unhandled\n exception in interactive mode (the traceback stored in\n "sys.last_traceback" keeps the stack frame alive). The first\n situation can only be remedied by explicitly breaking the cycles;\n the latter two situations can be resolved by storing "None" in\n "sys.last_traceback". Circular references which are garbage are\n detected and cleaned up when the cyclic garbage collector is\n enabled (it\'s on by default). Refer to the documentation for the\n "gc" module for more information about this topic.\n\n Warning: Due to the precarious circumstances under which "__del__()"\n methods are invoked, exceptions that occur during their execution\n are ignored, and a warning is printed to "sys.stderr" instead.\n Also, when "__del__()" is invoked in response to a module being\n deleted (e.g., when execution of the program is done), other\n globals referenced by the "__del__()" method may already have\n been deleted or in the process of being torn down (e.g. the\n import machinery shutting down). For this reason, "__del__()"\n methods should do the absolute minimum needed to maintain\n external invariants. Starting with version 1.5, Python\n guarantees that globals whose name begins with a single\n underscore are deleted from their module before other globals are\n deleted; if no other references to such globals exist, this may\n help in assuring that imported modules are still available at the\n time when the "__del__()" method is called.\n\nobject.__repr__(self)\n\n Called by the "repr()" built-in function to compute the "official"\n string representation of an object. If at all possible, this\n should look like a valid Python expression that could be used to\n recreate an object with the same value (given an appropriate\n environment). If this is not possible, a string of the form\n "<...some useful description...>" should be returned. The return\n value must be a string object. If a class defines "__repr__()" but\n not "__str__()", then "__repr__()" is also used when an "informal"\n string representation of instances of that class is required.\n\n This is typically used for debugging, so it is important that the\n representation is information-rich and unambiguous.\n\nobject.__str__(self)\n\n Called by "str(object)" and the built-in functions "format()" and\n "print()" to compute the "informal" or nicely printable string\n representation of an object. The return value must be a *string*\n object.\n\n This method differs from "object.__repr__()" in that there is no\n expectation that "__str__()" return a valid Python expression: a\n more convenient or concise representation can be used.\n\n The default implementation defined by the built-in type "object"\n calls "object.__repr__()".\n\nobject.__bytes__(self)\n\n Called by "bytes()" to compute a byte-string representation of an\n object. This should return a "bytes" object.\n\nobject.__format__(self, format_spec)\n\n Called by the "format()" built-in function (and by extension, the\n "str.format()" method of class "str") to produce a "formatted"\n string representation of an object. The "format_spec" argument is a\n string that contains a description of the formatting options\n desired. The interpretation of the "format_spec" argument is up to\n the type implementing "__format__()", however most classes will\n either delegate formatting to one of the built-in types, or use a\n similar formatting option syntax.\n\n See *Format Specification Mini-Language* for a description of the\n standard formatting syntax.\n\n The return value must be a string object.\n\n Changed in version 3.4: The __format__ method of "object" itself\n raises a "TypeError" if passed any non-empty string.\n\nobject.__lt__(self, other)\nobject.__le__(self, other)\nobject.__eq__(self, other)\nobject.__ne__(self, other)\nobject.__gt__(self, other)\nobject.__ge__(self, other)\n\n These are the so-called "rich comparison" methods. The\n correspondence between operator symbols and method names is as\n follows: "x<y" calls "x.__lt__(y)", "x<=y" calls "x.__le__(y)",\n "x==y" calls "x.__eq__(y)", "x!=y" calls "x.__ne__(y)", "x>y" calls\n "x.__gt__(y)", and "x>=y" calls "x.__ge__(y)".\n\n A rich comparison method may return the singleton "NotImplemented"\n if it does not implement the operation for a given pair of\n arguments. By convention, "False" and "True" are returned for a\n successful comparison. However, these methods can return any value,\n so if the comparison operator is used in a Boolean context (e.g.,\n in the condition of an "if" statement), Python will call "bool()"\n on the value to determine if the result is true or false.\n\n There are no implied relationships among the comparison operators.\n The truth of "x==y" does not imply that "x!=y" is false.\n Accordingly, when defining "__eq__()", one should also define\n "__ne__()" so that the operators will behave as expected. See the\n paragraph on "__hash__()" for some important notes on creating\n *hashable* objects which support custom comparison operations and\n are usable as dictionary keys.\n\n There are no swapped-argument versions of these methods (to be used\n when the left argument does not support the operation but the right\n argument does); rather, "__lt__()" and "__gt__()" are each other\'s\n reflection, "__le__()" and "__ge__()" are each other\'s reflection,\n and "__eq__()" and "__ne__()" are their own reflection.\n\n Arguments to rich comparison methods are never coerced.\n\n To automatically generate ordering operations from a single root\n operation, see "functools.total_ordering()".\n\nobject.__hash__(self)\n\n Called by built-in function "hash()" and for operations on members\n of hashed collections including "set", "frozenset", and "dict".\n "__hash__()" should return an integer. The only required property\n is that objects which compare equal have the same hash value; it is\n advised to somehow mix together (e.g. using exclusive or) the hash\n values for the components of the object that also play a part in\n comparison of objects.\n\n Note: "hash()" truncates the value returned from an object\'s custom\n "__hash__()" method to the size of a "Py_ssize_t". This is\n typically 8 bytes on 64-bit builds and 4 bytes on 32-bit builds.\n If an object\'s "__hash__()" must interoperate on builds of\n different bit sizes, be sure to check the width on all supported\n builds. An easy way to do this is with "python -c "import sys;\n print(sys.hash_info.width)""\n\n If a class does not define an "__eq__()" method it should not\n define a "__hash__()" operation either; if it defines "__eq__()"\n but not "__hash__()", its instances will not be usable as items in\n hashable collections. If a class defines mutable objects and\n implements an "__eq__()" method, it should not implement\n "__hash__()", since the implementation of hashable collections\n requires that a key\'s hash value is immutable (if the object\'s hash\n value changes, it will be in the wrong hash bucket).\n\n User-defined classes have "__eq__()" and "__hash__()" methods by\n default; with them, all objects compare unequal (except with\n themselves) and "x.__hash__()" returns an appropriate value such\n that "x == y" implies both that "x is y" and "hash(x) == hash(y)".\n\n A class that overrides "__eq__()" and does not define "__hash__()"\n will have its "__hash__()" implicitly set to "None". When the\n "__hash__()" method of a class is "None", instances of the class\n will raise an appropriate "TypeError" when a program attempts to\n retrieve their hash value, and will also be correctly identified as\n unhashable when checking "isinstance(obj, collections.Hashable").\n\n If a class that overrides "__eq__()" needs to retain the\n implementation of "__hash__()" from a parent class, the interpreter\n must be told this explicitly by setting "__hash__ =\n <ParentClass>.__hash__".\n\n If a class that does not override "__eq__()" wishes to suppress\n hash support, it should include "__hash__ = None" in the class\n definition. A class which defines its own "__hash__()" that\n explicitly raises a "TypeError" would be incorrectly identified as\n hashable by an "isinstance(obj, collections.Hashable)" call.\n\n Note: By default, the "__hash__()" values of str, bytes and datetime\n objects are "salted" with an unpredictable random value.\n Although they remain constant within an individual Python\n process, they are not predictable between repeated invocations of\n Python.This is intended to provide protection against a denial-\n of-service caused by carefully-chosen inputs that exploit the\n worst case performance of a dict insertion, O(n^2) complexity.\n See http://www.ocert.org/advisories/ocert-2011-003.html for\n details.Changing hash values affects the iteration order of\n dicts, sets and other mappings. Python has never made guarantees\n about this ordering (and it typically varies between 32-bit and\n 64-bit builds).See also "PYTHONHASHSEED".\n\n Changed in version 3.3: Hash randomization is enabled by default.\n\nobject.__bool__(self)\n\n Called to implement truth value testing and the built-in operation\n "bool()"; should return "False" or "True". When this method is not\n defined, "__len__()" is called, if it is defined, and the object is\n considered true if its result is nonzero. If a class defines\n neither "__len__()" nor "__bool__()", all its instances are\n considered true.\n', - 'debugger': '\n"pdb" --- The Python Debugger\n*****************************\n\nThe module "pdb" defines an interactive source code debugger for\nPython programs. It supports setting (conditional) breakpoints and\nsingle stepping at the source line level, inspection of stack frames,\nsource code listing, and evaluation of arbitrary Python code in the\ncontext of any stack frame. It also supports post-mortem debugging\nand can be called under program control.\n\nThe debugger is extensible -- it is actually defined as the class\n"Pdb". This is currently undocumented but easily understood by reading\nthe source. The extension interface uses the modules "bdb" and "cmd".\n\nThe debugger\'s prompt is "(Pdb)". Typical usage to run a program under\ncontrol of the debugger is:\n\n >>> import pdb\n >>> import mymodule\n >>> pdb.run(\'mymodule.test()\')\n > <string>(0)?()\n (Pdb) continue\n > <string>(1)?()\n (Pdb) continue\n NameError: \'spam\'\n > <string>(1)?()\n (Pdb)\n\nChanged in version 3.3: Tab-completion via the "readline" module is\navailable for commands and command arguments, e.g. the current global\nand local names are offered as arguments of the "p" command.\n\n"pdb.py" can also be invoked as a script to debug other scripts. For\nexample:\n\n python3 -m pdb myscript.py\n\nWhen invoked as a script, pdb will automatically enter post-mortem\ndebugging if the program being debugged exits abnormally. After post-\nmortem debugging (or after normal exit of the program), pdb will\nrestart the program. Automatic restarting preserves pdb\'s state (such\nas breakpoints) and in most cases is more useful than quitting the\ndebugger upon program\'s exit.\n\nNew in version 3.2: "pdb.py" now accepts a "-c" option that executes\ncommands as if given in a ".pdbrc" file, see *Debugger Commands*.\n\nThe typical usage to break into the debugger from a running program is\nto insert\n\n import pdb; pdb.set_trace()\n\nat the location you want to break into the debugger. You can then\nstep through the code following this statement, and continue running\nwithout the debugger using the "continue" command.\n\nThe typical usage to inspect a crashed program is:\n\n >>> import pdb\n >>> import mymodule\n >>> mymodule.test()\n Traceback (most recent call last):\n File "<stdin>", line 1, in ?\n File "./mymodule.py", line 4, in test\n test2()\n File "./mymodule.py", line 3, in test2\n print(spam)\n NameError: spam\n >>> pdb.pm()\n > ./mymodule.py(3)test2()\n -> print(spam)\n (Pdb)\n\nThe module defines the following functions; each enters the debugger\nin a slightly different way:\n\npdb.run(statement, globals=None, locals=None)\n\n Execute the *statement* (given as a string or a code object) under\n debugger control. The debugger prompt appears before any code is\n executed; you can set breakpoints and type "continue", or you can\n step through the statement using "step" or "next" (all these\n commands are explained below). The optional *globals* and *locals*\n arguments specify the environment in which the code is executed; by\n default the dictionary of the module "__main__" is used. (See the\n explanation of the built-in "exec()" or "eval()" functions.)\n\npdb.runeval(expression, globals=None, locals=None)\n\n Evaluate the *expression* (given as a string or a code object)\n under debugger control. When "runeval()" returns, it returns the\n value of the expression. Otherwise this function is similar to\n "run()".\n\npdb.runcall(function, *args, **kwds)\n\n Call the *function* (a function or method object, not a string)\n with the given arguments. When "runcall()" returns, it returns\n whatever the function call returned. The debugger prompt appears\n as soon as the function is entered.\n\npdb.set_trace()\n\n Enter the debugger at the calling stack frame. This is useful to\n hard-code a breakpoint at a given point in a program, even if the\n code is not otherwise being debugged (e.g. when an assertion\n fails).\n\npdb.post_mortem(traceback=None)\n\n Enter post-mortem debugging of the given *traceback* object. If no\n *traceback* is given, it uses the one of the exception that is\n currently being handled (an exception must be being handled if the\n default is to be used).\n\npdb.pm()\n\n Enter post-mortem debugging of the traceback found in\n "sys.last_traceback".\n\nThe "run*" functions and "set_trace()" are aliases for instantiating\nthe "Pdb" class and calling the method of the same name. If you want\nto access further features, you have to do this yourself:\n\nclass class pdb.Pdb(completekey=\'tab\', stdin=None, stdout=None, skip=None, nosigint=False)\n\n "Pdb" is the debugger class.\n\n The *completekey*, *stdin* and *stdout* arguments are passed to the\n underlying "cmd.Cmd" class; see the description there.\n\n The *skip* argument, if given, must be an iterable of glob-style\n module name patterns. The debugger will not step into frames that\n originate in a module that matches one of these patterns. [1]\n\n By default, Pdb sets a handler for the SIGINT signal (which is sent\n when the user presses Ctrl-C on the console) when you give a\n "continue" command. This allows you to break into the debugger\n again by pressing Ctrl-C. If you want Pdb not to touch the SIGINT\n handler, set *nosigint* tot true.\n\n Example call to enable tracing with *skip*:\n\n import pdb; pdb.Pdb(skip=[\'django.*\']).set_trace()\n\n New in version 3.1: The *skip* argument.\n\n New in version 3.2: The *nosigint* argument. Previously, a SIGINT\n handler was never set by Pdb.\n\n run(statement, globals=None, locals=None)\n runeval(expression, globals=None, locals=None)\n runcall(function, *args, **kwds)\n set_trace()\n\n See the documentation for the functions explained above.\n\n\nDebugger Commands\n=================\n\nThe commands recognized by the debugger are listed below. Most\ncommands can be abbreviated to one or two letters as indicated; e.g.\n"h(elp)" means that either "h" or "help" can be used to enter the help\ncommand (but not "he" or "hel", nor "H" or "Help" or "HELP").\nArguments to commands must be separated by whitespace (spaces or\ntabs). Optional arguments are enclosed in square brackets ("[]") in\nthe command syntax; the square brackets must not be typed.\nAlternatives in the command syntax are separated by a vertical bar\n("|").\n\nEntering a blank line repeats the last command entered. Exception: if\nthe last command was a "list" command, the next 11 lines are listed.\n\nCommands that the debugger doesn\'t recognize are assumed to be Python\nstatements and are executed in the context of the program being\ndebugged. Python statements can also be prefixed with an exclamation\npoint ("!"). This is a powerful way to inspect the program being\ndebugged; it is even possible to change a variable or call a function.\nWhen an exception occurs in such a statement, the exception name is\nprinted but the debugger\'s state is not changed.\n\nThe debugger supports *aliases*. Aliases can have parameters which\nallows one a certain level of adaptability to the context under\nexamination.\n\nMultiple commands may be entered on a single line, separated by ";;".\n(A single ";" is not used as it is the separator for multiple commands\nin a line that is passed to the Python parser.) No intelligence is\napplied to separating the commands; the input is split at the first\n";;" pair, even if it is in the middle of a quoted string.\n\nIf a file ".pdbrc" exists in the user\'s home directory or in the\ncurrent directory, it is read in and executed as if it had been typed\nat the debugger prompt. This is particularly useful for aliases. If\nboth files exist, the one in the home directory is read first and\naliases defined there can be overridden by the local file.\n\nChanged in version 3.2: ".pdbrc" can now contain commands that\ncontinue debugging, such as "continue" or "next". Previously, these\ncommands had no effect.\n\nh(elp) [command]\n\n Without argument, print the list of available commands. With a\n *command* as argument, print help about that command. "help pdb"\n displays the full documentation (the docstring of the "pdb"\n module). Since the *command* argument must be an identifier, "help\n exec" must be entered to get help on the "!" command.\n\nw(here)\n\n Print a stack trace, with the most recent frame at the bottom. An\n arrow indicates the current frame, which determines the context of\n most commands.\n\nd(own) [count]\n\n Move the current frame *count* (default one) levels down in the\n stack trace (to a newer frame).\n\nu(p) [count]\n\n Move the current frame *count* (default one) levels up in the stack\n trace (to an older frame).\n\nb(reak) [([filename:]lineno | function) [, condition]]\n\n With a *lineno* argument, set a break there in the current file.\n With a *function* argument, set a break at the first executable\n statement within that function. The line number may be prefixed\n with a filename and a colon, to specify a breakpoint in another\n file (probably one that hasn\'t been loaded yet). The file is\n searched on "sys.path". Note that each breakpoint is assigned a\n number to which all the other breakpoint commands refer.\n\n If a second argument is present, it is an expression which must\n evaluate to true before the breakpoint is honored.\n\n Without argument, list all breaks, including for each breakpoint,\n the number of times that breakpoint has been hit, the current\n ignore count, and the associated condition if any.\n\ntbreak [([filename:]lineno | function) [, condition]]\n\n Temporary breakpoint, which is removed automatically when it is\n first hit. The arguments are the same as for "break".\n\ncl(ear) [filename:lineno | bpnumber [bpnumber ...]]\n\n With a *filename:lineno* argument, clear all the breakpoints at\n this line. With a space separated list of breakpoint numbers, clear\n those breakpoints. Without argument, clear all breaks (but first\n ask confirmation).\n\ndisable [bpnumber [bpnumber ...]]\n\n Disable the breakpoints given as a space separated list of\n breakpoint numbers. Disabling a breakpoint means it cannot cause\n the program to stop execution, but unlike clearing a breakpoint, it\n remains in the list of breakpoints and can be (re-)enabled.\n\nenable [bpnumber [bpnumber ...]]\n\n Enable the breakpoints specified.\n\nignore bpnumber [count]\n\n Set the ignore count for the given breakpoint number. If count is\n omitted, the ignore count is set to 0. A breakpoint becomes active\n when the ignore count is zero. When non-zero, the count is\n decremented each time the breakpoint is reached and the breakpoint\n is not disabled and any associated condition evaluates to true.\n\ncondition bpnumber [condition]\n\n Set a new *condition* for the breakpoint, an expression which must\n evaluate to true before the breakpoint is honored. If *condition*\n is absent, any existing condition is removed; i.e., the breakpoint\n is made unconditional.\n\ncommands [bpnumber]\n\n Specify a list of commands for breakpoint number *bpnumber*. The\n commands themselves appear on the following lines. Type a line\n containing just "end" to terminate the commands. An example:\n\n (Pdb) commands 1\n (com) p some_variable\n (com) end\n (Pdb)\n\n To remove all commands from a breakpoint, type commands and follow\n it immediately with "end"; that is, give no commands.\n\n With no *bpnumber* argument, commands refers to the last breakpoint\n set.\n\n You can use breakpoint commands to start your program up again.\n Simply use the continue command, or step, or any other command that\n resumes execution.\n\n Specifying any command resuming execution (currently continue,\n step, next, return, jump, quit and their abbreviations) terminates\n the command list (as if that command was immediately followed by\n end). This is because any time you resume execution (even with a\n simple next or step), you may encounter another breakpoint--which\n could have its own command list, leading to ambiguities about which\n list to execute.\n\n If you use the \'silent\' command in the command list, the usual\n message about stopping at a breakpoint is not printed. This may be\n desirable for breakpoints that are to print a specific message and\n then continue. If none of the other commands print anything, you\n see no sign that the breakpoint was reached.\n\ns(tep)\n\n Execute the current line, stop at the first possible occasion\n (either in a function that is called or on the next line in the\n current function).\n\nn(ext)\n\n Continue execution until the next line in the current function is\n reached or it returns. (The difference between "next" and "step"\n is that "step" stops inside a called function, while "next"\n executes called functions at (nearly) full speed, only stopping at\n the next line in the current function.)\n\nunt(il) [lineno]\n\n Without argument, continue execution until the line with a number\n greater than the current one is reached.\n\n With a line number, continue execution until a line with a number\n greater or equal to that is reached. In both cases, also stop when\n the current frame returns.\n\n Changed in version 3.2: Allow giving an explicit line number.\n\nr(eturn)\n\n Continue execution until the current function returns.\n\nc(ont(inue))\n\n Continue execution, only stop when a breakpoint is encountered.\n\nj(ump) lineno\n\n Set the next line that will be executed. Only available in the\n bottom-most frame. This lets you jump back and execute code again,\n or jump forward to skip code that you don\'t want to run.\n\n It should be noted that not all jumps are allowed -- for instance\n it is not possible to jump into the middle of a "for" loop or out\n of a "finally" clause.\n\nl(ist) [first[, last]]\n\n List source code for the current file. Without arguments, list 11\n lines around the current line or continue the previous listing.\n With "." as argument, list 11 lines around the current line. With\n one argument, list 11 lines around at that line. With two\n arguments, list the given range; if the second argument is less\n than the first, it is interpreted as a count.\n\n The current line in the current frame is indicated by "->". If an\n exception is being debugged, the line where the exception was\n originally raised or propagated is indicated by ">>", if it differs\n from the current line.\n\n New in version 3.2: The ">>" marker.\n\nll | longlist\n\n List all source code for the current function or frame.\n Interesting lines are marked as for "list".\n\n New in version 3.2.\n\na(rgs)\n\n Print the argument list of the current function.\n\np expression\n\n Evaluate the *expression* in the current context and print its\n value.\n\n Note: "print()" can also be used, but is not a debugger command ---\n this executes the Python "print()" function.\n\npp expression\n\n Like the "p" command, except the value of the expression is pretty-\n printed using the "pprint" module.\n\nwhatis expression\n\n Print the type of the *expression*.\n\nsource expression\n\n Try to get source code for the given object and display it.\n\n New in version 3.2.\n\ndisplay [expression]\n\n Display the value of the expression if it changed, each time\n execution stops in the current frame.\n\n Without expression, list all display expressions for the current\n frame.\n\n New in version 3.2.\n\nundisplay [expression]\n\n Do not display the expression any more in the current frame.\n Without expression, clear all display expressions for the current\n frame.\n\n New in version 3.2.\n\ninteract\n\n Start an interative interpreter (using the "code" module) whose\n global namespace contains all the (global and local) names found in\n the current scope.\n\n New in version 3.2.\n\nalias [name [command]]\n\n Create an alias called *name* that executes *command*. The command\n must *not* be enclosed in quotes. Replaceable parameters can be\n indicated by "%1", "%2", and so on, while "%*" is replaced by all\n the parameters. If no command is given, the current alias for\n *name* is shown. If no arguments are given, all aliases are listed.\n\n Aliases may be nested and can contain anything that can be legally\n typed at the pdb prompt. Note that internal pdb commands *can* be\n overridden by aliases. Such a command is then hidden until the\n alias is removed. Aliasing is recursively applied to the first\n word of the command line; all other words in the line are left\n alone.\n\n As an example, here are two useful aliases (especially when placed\n in the ".pdbrc" file):\n\n # Print instance variables (usage "pi classInst")\n alias pi for k in %1.__dict__.keys(): print("%1.",k,"=",%1.__dict__[k])\n # Print instance variables in self\n alias ps pi self\n\nunalias name\n\n Delete the specified alias.\n\n! statement\n\n Execute the (one-line) *statement* in the context of the current\n stack frame. The exclamation point can be omitted unless the first\n word of the statement resembles a debugger command. To set a\n global variable, you can prefix the assignment command with a\n "global" statement on the same line, e.g.:\n\n (Pdb) global list_options; list_options = [\'-l\']\n (Pdb)\n\nrun [args ...]\nrestart [args ...]\n\n Restart the debugged Python program. If an argument is supplied,\n it is split with "shlex" and the result is used as the new\n "sys.argv". History, breakpoints, actions and debugger options are\n preserved. "restart" is an alias for "run".\n\nq(uit)\n\n Quit from the debugger. The program being executed is aborted.\n\n-[ Footnotes ]-\n\n[1] Whether a frame is considered to originate in a certain module is\n determined by the "__name__" in the frame globals.\n', + 'conversions': '\nArithmetic conversions\n**********************\n\nWhen a description of an arithmetic operator below uses the phrase\n"the numeric arguments are converted to a common type," this means\nthat the operator implementation for built-in types works that way:\n\n* If either argument is a complex number, the other is converted to\n complex;\n\n* otherwise, if either argument is a floating point number, the\n other is converted to floating point;\n\n* otherwise, both must be integers and no conversion is necessary.\n\nSome additional rules apply for certain operators (e.g., a string left\nargument to the \'%\' operator). Extensions must define their own\nconversion behavior.\n', + 'customization': '\nBasic customization\n*******************\n\nobject.__new__(cls[, ...])\n\n Called to create a new instance of class *cls*. "__new__()" is a\n static method (special-cased so you need not declare it as such)\n that takes the class of which an instance was requested as its\n first argument. The remaining arguments are those passed to the\n object constructor expression (the call to the class). The return\n value of "__new__()" should be the new object instance (usually an\n instance of *cls*).\n\n Typical implementations create a new instance of the class by\n invoking the superclass\'s "__new__()" method using\n "super(currentclass, cls).__new__(cls[, ...])" with appropriate\n arguments and then modifying the newly-created instance as\n necessary before returning it.\n\n If "__new__()" returns an instance of *cls*, then the new\n instance\'s "__init__()" method will be invoked like\n "__init__(self[, ...])", where *self* is the new instance and the\n remaining arguments are the same as were passed to "__new__()".\n\n If "__new__()" does not return an instance of *cls*, then the new\n instance\'s "__init__()" method will not be invoked.\n\n "__new__()" is intended mainly to allow subclasses of immutable\n types (like int, str, or tuple) to customize instance creation. It\n is also commonly overridden in custom metaclasses in order to\n customize class creation.\n\nobject.__init__(self[, ...])\n\n Called when the instance is created. The arguments are those\n passed to the class constructor expression. If a base class has an\n "__init__()" method, the derived class\'s "__init__()" method, if\n any, must explicitly call it to ensure proper initialization of the\n base class part of the instance; for example:\n "BaseClass.__init__(self, [args...])". As a special constraint on\n constructors, no value may be returned; doing so will cause a\n "TypeError" to be raised at runtime.\n\nobject.__del__(self)\n\n Called when the instance is about to be destroyed. This is also\n called a destructor. If a base class has a "__del__()" method, the\n derived class\'s "__del__()" method, if any, must explicitly call it\n to ensure proper deletion of the base class part of the instance.\n Note that it is possible (though not recommended!) for the\n "__del__()" method to postpone destruction of the instance by\n creating a new reference to it. It may then be called at a later\n time when this new reference is deleted. It is not guaranteed that\n "__del__()" methods are called for objects that still exist when\n the interpreter exits.\n\n Note: "del x" doesn\'t directly call "x.__del__()" --- the former\n decrements the reference count for "x" by one, and the latter is\n only called when "x"\'s reference count reaches zero. Some common\n situations that may prevent the reference count of an object from\n going to zero include: circular references between objects (e.g.,\n a doubly-linked list or a tree data structure with parent and\n child pointers); a reference to the object on the stack frame of\n a function that caught an exception (the traceback stored in\n "sys.exc_info()[2]" keeps the stack frame alive); or a reference\n to the object on the stack frame that raised an unhandled\n exception in interactive mode (the traceback stored in\n "sys.last_traceback" keeps the stack frame alive). The first\n situation can only be remedied by explicitly breaking the cycles;\n the latter two situations can be resolved by storing "None" in\n "sys.last_traceback". Circular references which are garbage are\n detected and cleaned up when the cyclic garbage collector is\n enabled (it\'s on by default). Refer to the documentation for the\n "gc" module for more information about this topic.\n\n Warning: Due to the precarious circumstances under which\n "__del__()" methods are invoked, exceptions that occur during\n their execution are ignored, and a warning is printed to\n "sys.stderr" instead. Also, when "__del__()" is invoked in\n response to a module being deleted (e.g., when execution of the\n program is done), other globals referenced by the "__del__()"\n method may already have been deleted or in the process of being\n torn down (e.g. the import machinery shutting down). For this\n reason, "__del__()" methods should do the absolute minimum needed\n to maintain external invariants. Starting with version 1.5,\n Python guarantees that globals whose name begins with a single\n underscore are deleted from their module before other globals are\n deleted; if no other references to such globals exist, this may\n help in assuring that imported modules are still available at the\n time when the "__del__()" method is called.\n\nobject.__repr__(self)\n\n Called by the "repr()" built-in function to compute the "official"\n string representation of an object. If at all possible, this\n should look like a valid Python expression that could be used to\n recreate an object with the same value (given an appropriate\n environment). If this is not possible, a string of the form\n "<...some useful description...>" should be returned. The return\n value must be a string object. If a class defines "__repr__()" but\n not "__str__()", then "__repr__()" is also used when an "informal"\n string representation of instances of that class is required.\n\n This is typically used for debugging, so it is important that the\n representation is information-rich and unambiguous.\n\nobject.__str__(self)\n\n Called by "str(object)" and the built-in functions "format()" and\n "print()" to compute the "informal" or nicely printable string\n representation of an object. The return value must be a *string*\n object.\n\n This method differs from "object.__repr__()" in that there is no\n expectation that "__str__()" return a valid Python expression: a\n more convenient or concise representation can be used.\n\n The default implementation defined by the built-in type "object"\n calls "object.__repr__()".\n\nobject.__bytes__(self)\n\n Called by "bytes()" to compute a byte-string representation of an\n object. This should return a "bytes" object.\n\nobject.__format__(self, format_spec)\n\n Called by the "format()" built-in function (and by extension, the\n "str.format()" method of class "str") to produce a "formatted"\n string representation of an object. The "format_spec" argument is a\n string that contains a description of the formatting options\n desired. The interpretation of the "format_spec" argument is up to\n the type implementing "__format__()", however most classes will\n either delegate formatting to one of the built-in types, or use a\n similar formatting option syntax.\n\n See *Format Specification Mini-Language* for a description of the\n standard formatting syntax.\n\n The return value must be a string object.\n\nobject.__lt__(self, other)\nobject.__le__(self, other)\nobject.__eq__(self, other)\nobject.__ne__(self, other)\nobject.__gt__(self, other)\nobject.__ge__(self, other)\n\n These are the so-called "rich comparison" methods. The\n correspondence between operator symbols and method names is as\n follows: "x<y" calls "x.__lt__(y)", "x<=y" calls "x.__le__(y)",\n "x==y" calls "x.__eq__(y)", "x!=y" calls "x.__ne__(y)", "x>y" calls\n "x.__gt__(y)", and "x>=y" calls "x.__ge__(y)".\n\n A rich comparison method may return the singleton "NotImplemented"\n if it does not implement the operation for a given pair of\n arguments. By convention, "False" and "True" are returned for a\n successful comparison. However, these methods can return any value,\n so if the comparison operator is used in a Boolean context (e.g.,\n in the condition of an "if" statement), Python will call "bool()"\n on the value to determine if the result is true or false.\n\n There are no implied relationships among the comparison operators.\n The truth of "x==y" does not imply that "x!=y" is false.\n Accordingly, when defining "__eq__()", one should also define\n "__ne__()" so that the operators will behave as expected. See the\n paragraph on "__hash__()" for some important notes on creating\n *hashable* objects which support custom comparison operations and\n are usable as dictionary keys.\n\n There are no swapped-argument versions of these methods (to be used\n when the left argument does not support the operation but the right\n argument does); rather, "__lt__()" and "__gt__()" are each other\'s\n reflection, "__le__()" and "__ge__()" are each other\'s reflection,\n and "__eq__()" and "__ne__()" are their own reflection.\n\n Arguments to rich comparison methods are never coerced.\n\n To automatically generate ordering operations from a single root\n operation, see "functools.total_ordering()".\n\nobject.__hash__(self)\n\n Called by built-in function "hash()" and for operations on members\n of hashed collections including "set", "frozenset", and "dict".\n "__hash__()" should return an integer. The only required property\n is that objects which compare equal have the same hash value; it is\n advised to somehow mix together (e.g. using exclusive or) the hash\n values for the components of the object that also play a part in\n comparison of objects.\n\n Note: "hash()" truncates the value returned from an object\'s\n custom "__hash__()" method to the size of a "Py_ssize_t". This\n is typically 8 bytes on 64-bit builds and 4 bytes on 32-bit\n builds. If an object\'s "__hash__()" must interoperate on builds\n of different bit sizes, be sure to check the width on all\n supported builds. An easy way to do this is with "python -c\n "import sys; print(sys.hash_info.width)""\n\n If a class does not define an "__eq__()" method it should not\n define a "__hash__()" operation either; if it defines "__eq__()"\n but not "__hash__()", its instances will not be usable as items in\n hashable collections. If a class defines mutable objects and\n implements an "__eq__()" method, it should not implement\n "__hash__()", since the implementation of hashable collections\n requires that a key\'s hash value is immutable (if the object\'s hash\n value changes, it will be in the wrong hash bucket).\n\n User-defined classes have "__eq__()" and "__hash__()" methods by\n default; with them, all objects compare unequal (except with\n themselves) and "x.__hash__()" returns an appropriate value such\n that "x == y" implies both that "x is y" and "hash(x) == hash(y)".\n\n A class that overrides "__eq__()" and does not define "__hash__()"\n will have its "__hash__()" implicitly set to "None". When the\n "__hash__()" method of a class is "None", instances of the class\n will raise an appropriate "TypeError" when a program attempts to\n retrieve their hash value, and will also be correctly identified as\n unhashable when checking "isinstance(obj, collections.Hashable").\n\n If a class that overrides "__eq__()" needs to retain the\n implementation of "__hash__()" from a parent class, the interpreter\n must be told this explicitly by setting "__hash__ =\n <ParentClass>.__hash__".\n\n If a class that does not override "__eq__()" wishes to suppress\n hash support, it should include "__hash__ = None" in the class\n definition. A class which defines its own "__hash__()" that\n explicitly raises a "TypeError" would be incorrectly identified as\n hashable by an "isinstance(obj, collections.Hashable)" call.\n\n Note: By default, the "__hash__()" values of str, bytes and\n datetime objects are "salted" with an unpredictable random value.\n Although they remain constant within an individual Python\n process, they are not predictable between repeated invocations of\n Python.This is intended to provide protection against a denial-\n of-service caused by carefully-chosen inputs that exploit the\n worst case performance of a dict insertion, O(n^2) complexity.\n See http://www.ocert.org/advisories/ocert-2011-003.html for\n details.Changing hash values affects the iteration order of\n dicts, sets and other mappings. Python has never made guarantees\n about this ordering (and it typically varies between 32-bit and\n 64-bit builds).See also "PYTHONHASHSEED".\n\n Changed in version 3.3: Hash randomization is enabled by default.\n\nobject.__bool__(self)\n\n Called to implement truth value testing and the built-in operation\n "bool()"; should return "False" or "True". When this method is not\n defined, "__len__()" is called, if it is defined, and the object is\n considered true if its result is nonzero. If a class defines\n neither "__len__()" nor "__bool__()", all its instances are\n considered true.\n', + 'debugger': '\n"pdb" --- The Python Debugger\n*****************************\n\nThe module "pdb" defines an interactive source code debugger for\nPython programs. It supports setting (conditional) breakpoints and\nsingle stepping at the source line level, inspection of stack frames,\nsource code listing, and evaluation of arbitrary Python code in the\ncontext of any stack frame. It also supports post-mortem debugging\nand can be called under program control.\n\nThe debugger is extensible -- it is actually defined as the class\n"Pdb". This is currently undocumented but easily understood by reading\nthe source. The extension interface uses the modules "bdb" and "cmd".\n\nThe debugger\'s prompt is "(Pdb)". Typical usage to run a program under\ncontrol of the debugger is:\n\n >>> import pdb\n >>> import mymodule\n >>> pdb.run(\'mymodule.test()\')\n > <string>(0)?()\n (Pdb) continue\n > <string>(1)?()\n (Pdb) continue\n NameError: \'spam\'\n > <string>(1)?()\n (Pdb)\n\nChanged in version 3.3: Tab-completion via the "readline" module is\navailable for commands and command arguments, e.g. the current global\nand local names are offered as arguments of the "p" command.\n\n"pdb.py" can also be invoked as a script to debug other scripts. For\nexample:\n\n python3 -m pdb myscript.py\n\nWhen invoked as a script, pdb will automatically enter post-mortem\ndebugging if the program being debugged exits abnormally. After post-\nmortem debugging (or after normal exit of the program), pdb will\nrestart the program. Automatic restarting preserves pdb\'s state (such\nas breakpoints) and in most cases is more useful than quitting the\ndebugger upon program\'s exit.\n\nNew in version 3.2: "pdb.py" now accepts a "-c" option that executes\ncommands as if given in a ".pdbrc" file, see *Debugger Commands*.\n\nThe typical usage to break into the debugger from a running program is\nto insert\n\n import pdb; pdb.set_trace()\n\nat the location you want to break into the debugger. You can then\nstep through the code following this statement, and continue running\nwithout the debugger using the "continue" command.\n\nThe typical usage to inspect a crashed program is:\n\n >>> import pdb\n >>> import mymodule\n >>> mymodule.test()\n Traceback (most recent call last):\n File "<stdin>", line 1, in ?\n File "./mymodule.py", line 4, in test\n test2()\n File "./mymodule.py", line 3, in test2\n print(spam)\n NameError: spam\n >>> pdb.pm()\n > ./mymodule.py(3)test2()\n -> print(spam)\n (Pdb)\n\nThe module defines the following functions; each enters the debugger\nin a slightly different way:\n\npdb.run(statement, globals=None, locals=None)\n\n Execute the *statement* (given as a string or a code object) under\n debugger control. The debugger prompt appears before any code is\n executed; you can set breakpoints and type "continue", or you can\n step through the statement using "step" or "next" (all these\n commands are explained below). The optional *globals* and *locals*\n arguments specify the environment in which the code is executed; by\n default the dictionary of the module "__main__" is used. (See the\n explanation of the built-in "exec()" or "eval()" functions.)\n\npdb.runeval(expression, globals=None, locals=None)\n\n Evaluate the *expression* (given as a string or a code object)\n under debugger control. When "runeval()" returns, it returns the\n value of the expression. Otherwise this function is similar to\n "run()".\n\npdb.runcall(function, *args, **kwds)\n\n Call the *function* (a function or method object, not a string)\n with the given arguments. When "runcall()" returns, it returns\n whatever the function call returned. The debugger prompt appears\n as soon as the function is entered.\n\npdb.set_trace()\n\n Enter the debugger at the calling stack frame. This is useful to\n hard-code a breakpoint at a given point in a program, even if the\n code is not otherwise being debugged (e.g. when an assertion\n fails).\n\npdb.post_mortem(traceback=None)\n\n Enter post-mortem debugging of the given *traceback* object. If no\n *traceback* is given, it uses the one of the exception that is\n currently being handled (an exception must be being handled if the\n default is to be used).\n\npdb.pm()\n\n Enter post-mortem debugging of the traceback found in\n "sys.last_traceback".\n\nThe "run*" functions and "set_trace()" are aliases for instantiating\nthe "Pdb" class and calling the method of the same name. If you want\nto access further features, you have to do this yourself:\n\nclass class pdb.Pdb(completekey=\'tab\', stdin=None, stdout=None, skip=None, nosigint=False)\n\n "Pdb" is the debugger class.\n\n The *completekey*, *stdin* and *stdout* arguments are passed to the\n underlying "cmd.Cmd" class; see the description there.\n\n The *skip* argument, if given, must be an iterable of glob-style\n module name patterns. The debugger will not step into frames that\n originate in a module that matches one of these patterns. [1]\n\n By default, Pdb sets a handler for the SIGINT signal (which is sent\n when the user presses Ctrl-C on the console) when you give a\n "continue" command. This allows you to break into the debugger\n again by pressing Ctrl-C. If you want Pdb not to touch the SIGINT\n handler, set *nosigint* tot true.\n\n Example call to enable tracing with *skip*:\n\n import pdb; pdb.Pdb(skip=[\'django.*\']).set_trace()\n\n New in version 3.1: The *skip* argument.\n\n New in version 3.2: The *nosigint* argument. Previously, a SIGINT\n handler was never set by Pdb.\n\n run(statement, globals=None, locals=None)\n runeval(expression, globals=None, locals=None)\n runcall(function, *args, **kwds)\n set_trace()\n\n See the documentation for the functions explained above.\n\n\nDebugger Commands\n=================\n\nThe commands recognized by the debugger are listed below. Most\ncommands can be abbreviated to one or two letters as indicated; e.g.\n"h(elp)" means that either "h" or "help" can be used to enter the help\ncommand (but not "he" or "hel", nor "H" or "Help" or "HELP").\nArguments to commands must be separated by whitespace (spaces or\ntabs). Optional arguments are enclosed in square brackets ("[]") in\nthe command syntax; the square brackets must not be typed.\nAlternatives in the command syntax are separated by a vertical bar\n("|").\n\nEntering a blank line repeats the last command entered. Exception: if\nthe last command was a "list" command, the next 11 lines are listed.\n\nCommands that the debugger doesn\'t recognize are assumed to be Python\nstatements and are executed in the context of the program being\ndebugged. Python statements can also be prefixed with an exclamation\npoint ("!"). This is a powerful way to inspect the program being\ndebugged; it is even possible to change a variable or call a function.\nWhen an exception occurs in such a statement, the exception name is\nprinted but the debugger\'s state is not changed.\n\nThe debugger supports *aliases*. Aliases can have parameters which\nallows one a certain level of adaptability to the context under\nexamination.\n\nMultiple commands may be entered on a single line, separated by ";;".\n(A single ";" is not used as it is the separator for multiple commands\nin a line that is passed to the Python parser.) No intelligence is\napplied to separating the commands; the input is split at the first\n";;" pair, even if it is in the middle of a quoted string.\n\nIf a file ".pdbrc" exists in the user\'s home directory or in the\ncurrent directory, it is read in and executed as if it had been typed\nat the debugger prompt. This is particularly useful for aliases. If\nboth files exist, the one in the home directory is read first and\naliases defined there can be overridden by the local file.\n\nChanged in version 3.2: ".pdbrc" can now contain commands that\ncontinue debugging, such as "continue" or "next". Previously, these\ncommands had no effect.\n\nh(elp) [command]\n\n Without argument, print the list of available commands. With a\n *command* as argument, print help about that command. "help pdb"\n displays the full documentation (the docstring of the "pdb"\n module). Since the *command* argument must be an identifier, "help\n exec" must be entered to get help on the "!" command.\n\nw(here)\n\n Print a stack trace, with the most recent frame at the bottom. An\n arrow indicates the current frame, which determines the context of\n most commands.\n\nd(own) [count]\n\n Move the current frame *count* (default one) levels down in the\n stack trace (to a newer frame).\n\nu(p) [count]\n\n Move the current frame *count* (default one) levels up in the stack\n trace (to an older frame).\n\nb(reak) [([filename:]lineno | function) [, condition]]\n\n With a *lineno* argument, set a break there in the current file.\n With a *function* argument, set a break at the first executable\n statement within that function. The line number may be prefixed\n with a filename and a colon, to specify a breakpoint in another\n file (probably one that hasn\'t been loaded yet). The file is\n searched on "sys.path". Note that each breakpoint is assigned a\n number to which all the other breakpoint commands refer.\n\n If a second argument is present, it is an expression which must\n evaluate to true before the breakpoint is honored.\n\n Without argument, list all breaks, including for each breakpoint,\n the number of times that breakpoint has been hit, the current\n ignore count, and the associated condition if any.\n\ntbreak [([filename:]lineno | function) [, condition]]\n\n Temporary breakpoint, which is removed automatically when it is\n first hit. The arguments are the same as for "break".\n\ncl(ear) [filename:lineno | bpnumber [bpnumber ...]]\n\n With a *filename:lineno* argument, clear all the breakpoints at\n this line. With a space separated list of breakpoint numbers, clear\n those breakpoints. Without argument, clear all breaks (but first\n ask confirmation).\n\ndisable [bpnumber [bpnumber ...]]\n\n Disable the breakpoints given as a space separated list of\n breakpoint numbers. Disabling a breakpoint means it cannot cause\n the program to stop execution, but unlike clearing a breakpoint, it\n remains in the list of breakpoints and can be (re-)enabled.\n\nenable [bpnumber [bpnumber ...]]\n\n Enable the breakpoints specified.\n\nignore bpnumber [count]\n\n Set the ignore count for the given breakpoint number. If count is\n omitted, the ignore count is set to 0. A breakpoint becomes active\n when the ignore count is zero. When non-zero, the count is\n decremented each time the breakpoint is reached and the breakpoint\n is not disabled and any associated condition evaluates to true.\n\ncondition bpnumber [condition]\n\n Set a new *condition* for the breakpoint, an expression which must\n evaluate to true before the breakpoint is honored. If *condition*\n is absent, any existing condition is removed; i.e., the breakpoint\n is made unconditional.\n\ncommands [bpnumber]\n\n Specify a list of commands for breakpoint number *bpnumber*. The\n commands themselves appear on the following lines. Type a line\n containing just "end" to terminate the commands. An example:\n\n (Pdb) commands 1\n (com) p some_variable\n (com) end\n (Pdb)\n\n To remove all commands from a breakpoint, type commands and follow\n it immediately with "end"; that is, give no commands.\n\n With no *bpnumber* argument, commands refers to the last breakpoint\n set.\n\n You can use breakpoint commands to start your program up again.\n Simply use the continue command, or step, or any other command that\n resumes execution.\n\n Specifying any command resuming execution (currently continue,\n step, next, return, jump, quit and their abbreviations) terminates\n the command list (as if that command was immediately followed by\n end). This is because any time you resume execution (even with a\n simple next or step), you may encounter another breakpoint--which\n could have its own command list, leading to ambiguities about which\n list to execute.\n\n If you use the \'silent\' command in the command list, the usual\n message about stopping at a breakpoint is not printed. This may be\n desirable for breakpoints that are to print a specific message and\n then continue. If none of the other commands print anything, you\n see no sign that the breakpoint was reached.\n\ns(tep)\n\n Execute the current line, stop at the first possible occasion\n (either in a function that is called or on the next line in the\n current function).\n\nn(ext)\n\n Continue execution until the next line in the current function is\n reached or it returns. (The difference between "next" and "step"\n is that "step" stops inside a called function, while "next"\n executes called functions at (nearly) full speed, only stopping at\n the next line in the current function.)\n\nunt(il) [lineno]\n\n Without argument, continue execution until the line with a number\n greater than the current one is reached.\n\n With a line number, continue execution until a line with a number\n greater or equal to that is reached. In both cases, also stop when\n the current frame returns.\n\n Changed in version 3.2: Allow giving an explicit line number.\n\nr(eturn)\n\n Continue execution until the current function returns.\n\nc(ont(inue))\n\n Continue execution, only stop when a breakpoint is encountered.\n\nj(ump) lineno\n\n Set the next line that will be executed. Only available in the\n bottom-most frame. This lets you jump back and execute code again,\n or jump forward to skip code that you don\'t want to run.\n\n It should be noted that not all jumps are allowed -- for instance\n it is not possible to jump into the middle of a "for" loop or out\n of a "finally" clause.\n\nl(ist) [first[, last]]\n\n List source code for the current file. Without arguments, list 11\n lines around the current line or continue the previous listing.\n With "." as argument, list 11 lines around the current line. With\n one argument, list 11 lines around at that line. With two\n arguments, list the given range; if the second argument is less\n than the first, it is interpreted as a count.\n\n The current line in the current frame is indicated by "->". If an\n exception is being debugged, the line where the exception was\n originally raised or propagated is indicated by ">>", if it differs\n from the current line.\n\n New in version 3.2: The ">>" marker.\n\nll | longlist\n\n List all source code for the current function or frame.\n Interesting lines are marked as for "list".\n\n New in version 3.2.\n\na(rgs)\n\n Print the argument list of the current function.\n\np expression\n\n Evaluate the *expression* in the current context and print its\n value.\n\n Note: "print()" can also be used, but is not a debugger command\n --- this executes the Python "print()" function.\n\npp expression\n\n Like the "p" command, except the value of the expression is pretty-\n printed using the "pprint" module.\n\nwhatis expression\n\n Print the type of the *expression*.\n\nsource expression\n\n Try to get source code for the given object and display it.\n\n New in version 3.2.\n\ndisplay [expression]\n\n Display the value of the expression if it changed, each time\n execution stops in the current frame.\n\n Without expression, list all display expressions for the current\n frame.\n\n New in version 3.2.\n\nundisplay [expression]\n\n Do not display the expression any more in the current frame.\n Without expression, clear all display expressions for the current\n frame.\n\n New in version 3.2.\n\ninteract\n\n Start an interative interpreter (using the "code" module) whose\n global namespace contains all the (global and local) names found in\n the current scope.\n\n New in version 3.2.\n\nalias [name [command]]\n\n Create an alias called *name* that executes *command*. The command\n must *not* be enclosed in quotes. Replaceable parameters can be\n indicated by "%1", "%2", and so on, while "%*" is replaced by all\n the parameters. If no command is given, the current alias for\n *name* is shown. If no arguments are given, all aliases are listed.\n\n Aliases may be nested and can contain anything that can be legally\n typed at the pdb prompt. Note that internal pdb commands *can* be\n overridden by aliases. Such a command is then hidden until the\n alias is removed. Aliasing is recursively applied to the first\n word of the command line; all other words in the line are left\n alone.\n\n As an example, here are two useful aliases (especially when placed\n in the ".pdbrc" file):\n\n # Print instance variables (usage "pi classInst")\n alias pi for k in %1.__dict__.keys(): print("%1.",k,"=",%1.__dict__[k])\n # Print instance variables in self\n alias ps pi self\n\nunalias name\n\n Delete the specified alias.\n\n! statement\n\n Execute the (one-line) *statement* in the context of the current\n stack frame. The exclamation point can be omitted unless the first\n word of the statement resembles a debugger command. To set a\n global variable, you can prefix the assignment command with a\n "global" statement on the same line, e.g.:\n\n (Pdb) global list_options; list_options = [\'-l\']\n (Pdb)\n\nrun [args ...]\nrestart [args ...]\n\n Restart the debugged Python program. If an argument is supplied,\n it is split with "shlex" and the result is used as the new\n "sys.argv". History, breakpoints, actions and debugger options are\n preserved. "restart" is an alias for "run".\n\nq(uit)\n\n Quit from the debugger. The program being executed is aborted.\n\n-[ Footnotes ]-\n\n[1] Whether a frame is considered to originate in a certain module\n is determined by the "__name__" in the frame globals.\n', 'del': '\nThe "del" statement\n*******************\n\n del_stmt ::= "del" target_list\n\nDeletion is recursively defined very similar to the way assignment is\ndefined. Rather than spelling it out in full details, here are some\nhints.\n\nDeletion of a target list recursively deletes each target, from left\nto right.\n\nDeletion of a name removes the binding of that name from the local or\nglobal namespace, depending on whether the name occurs in a "global"\nstatement in the same code block. If the name is unbound, a\n"NameError" exception will be raised.\n\nDeletion of attribute references, subscriptions and slicings is passed\nto the primary object involved; deletion of a slicing is in general\nequivalent to assignment of an empty slice of the right type (but even\nthis is determined by the sliced object).\n\nChanged in version 3.2: Previously it was illegal to delete a name\nfrom the local namespace if it occurs as a free variable in a nested\nblock.\n', 'dict': '\nDictionary displays\n*******************\n\nA dictionary display is a possibly empty series of key/datum pairs\nenclosed in curly braces:\n\n dict_display ::= "{" [key_datum_list | dict_comprehension] "}"\n key_datum_list ::= key_datum ("," key_datum)* [","]\n key_datum ::= expression ":" expression\n dict_comprehension ::= expression ":" expression comp_for\n\nA dictionary display yields a new dictionary object.\n\nIf a comma-separated sequence of key/datum pairs is given, they are\nevaluated from left to right to define the entries of the dictionary:\neach key object is used as a key into the dictionary to store the\ncorresponding datum. This means that you can specify the same key\nmultiple times in the key/datum list, and the final dictionary\'s value\nfor that key will be the last one given.\n\nA dict comprehension, in contrast to list and set comprehensions,\nneeds two expressions separated with a colon followed by the usual\n"for" and "if" clauses. When the comprehension is run, the resulting\nkey and value elements are inserted in the new dictionary in the order\nthey are produced.\n\nRestrictions on the types of the key values are listed earlier in\nsection *The standard type hierarchy*. (To summarize, the key type\nshould be *hashable*, which excludes all mutable objects.) Clashes\nbetween duplicate keys are not detected; the last datum (textually\nrightmost in the display) stored for a given key value prevails.\n', 'dynamic-features': '\nInteraction with dynamic features\n*********************************\n\nThere are several cases where Python statements are illegal when used\nin conjunction with nested scopes that contain free variables.\n\nIf a variable is referenced in an enclosing scope, it is illegal to\ndelete the name. An error will be reported at compile time.\n\nIf the wild card form of import --- "import *" --- is used in a\nfunction and the function contains or is a nested block with free\nvariables, the compiler will raise a "SyntaxError".\n\nThe "eval()" and "exec()" functions do not have access to the full\nenvironment for resolving names. Names may be resolved in the local\nand global namespaces of the caller. Free variables are not resolved\nin the nearest enclosing namespace, but in the global namespace. [1]\nThe "exec()" and "eval()" functions have optional arguments to\noverride the global and local namespace. If only one namespace is\nspecified, it is used for both.\n', 'else': '\nThe "if" statement\n******************\n\nThe "if" statement is used for conditional execution:\n\n if_stmt ::= "if" expression ":" suite\n ( "elif" expression ":" suite )*\n ["else" ":" suite]\n\nIt selects exactly one of the suites by evaluating the expressions one\nby one until one is found to be true (see section *Boolean operations*\nfor the definition of true and false); then that suite is executed\n(and no other part of the "if" statement is executed or evaluated).\nIf all expressions are false, the suite of the "else" clause, if\npresent, is executed.\n', - 'exceptions': '\nExceptions\n**********\n\nExceptions are a means of breaking out of the normal flow of control\nof a code block in order to handle errors or other exceptional\nconditions. An exception is *raised* at the point where the error is\ndetected; it may be *handled* by the surrounding code block or by any\ncode block that directly or indirectly invoked the code block where\nthe error occurred.\n\nThe Python interpreter raises an exception when it detects a run-time\nerror (such as division by zero). A Python program can also\nexplicitly raise an exception with the "raise" statement. Exception\nhandlers are specified with the "try" ... "except" statement. The\n"finally" clause of such a statement can be used to specify cleanup\ncode which does not handle the exception, but is executed whether an\nexception occurred or not in the preceding code.\n\nPython uses the "termination" model of error handling: an exception\nhandler can find out what happened and continue execution at an outer\nlevel, but it cannot repair the cause of the error and retry the\nfailing operation (except by re-entering the offending piece of code\nfrom the top).\n\nWhen an exception is not handled at all, the interpreter terminates\nexecution of the program, or returns to its interactive main loop. In\neither case, it prints a stack backtrace, except when the exception is\n"SystemExit".\n\nExceptions are identified by class instances. The "except" clause is\nselected depending on the class of the instance: it must reference the\nclass of the instance or a base class thereof. The instance can be\nreceived by the handler and can carry additional information about the\nexceptional condition.\n\nNote: Exception messages are not part of the Python API. Their contents\n may change from one version of Python to the next without warning\n and should not be relied on by code which will run under multiple\n versions of the interpreter.\n\nSee also the description of the "try" statement in section *The try\nstatement* and "raise" statement in section *The raise statement*.\n\n-[ Footnotes ]-\n\n[1] This limitation occurs because the code that is executed by these\n operations is not available at the time the module is compiled.\n', - 'execmodel': '\nExecution model\n***************\n\n\nNaming and binding\n==================\n\n*Names* refer to objects. Names are introduced by name binding\noperations. Each occurrence of a name in the program text refers to\nthe *binding* of that name established in the innermost function block\ncontaining the use.\n\nA *block* is a piece of Python program text that is executed as a\nunit. The following are blocks: a module, a function body, and a class\ndefinition. Each command typed interactively is a block. A script\nfile (a file given as standard input to the interpreter or specified\non the interpreter command line the first argument) is a code block.\nA script command (a command specified on the interpreter command line\nwith the \'**-c**\' option) is a code block. The string argument passed\nto the built-in functions "eval()" and "exec()" is a code block.\n\nA code block is executed in an *execution frame*. A frame contains\nsome administrative information (used for debugging) and determines\nwhere and how execution continues after the code block\'s execution has\ncompleted.\n\nA *scope* defines the visibility of a name within a block. If a local\nvariable is defined in a block, its scope includes that block. If the\ndefinition occurs in a function block, the scope extends to any blocks\ncontained within the defining one, unless a contained block introduces\na different binding for the name. The scope of names defined in a\nclass block is limited to the class block; it does not extend to the\ncode blocks of methods -- this includes comprehensions and generator\nexpressions since they are implemented using a function scope. This\nmeans that the following will fail:\n\n class A:\n a = 42\n b = list(a + i for i in range(10))\n\nWhen a name is used in a code block, it is resolved using the nearest\nenclosing scope. The set of all such scopes visible to a code block\nis called the block\'s *environment*.\n\nIf a name is bound in a block, it is a local variable of that block,\nunless declared as "nonlocal". If a name is bound at the module\nlevel, it is a global variable. (The variables of the module code\nblock are local and global.) If a variable is used in a code block\nbut not defined there, it is a *free variable*.\n\nWhen a name is not found at all, a "NameError" exception is raised.\nIf the name refers to a local variable that has not been bound, a\n"UnboundLocalError" exception is raised. "UnboundLocalError" is a\nsubclass of "NameError".\n\nThe following constructs bind names: formal parameters to functions,\n"import" statements, class and function definitions (these bind the\nclass or function name in the defining block), and targets that are\nidentifiers if occurring in an assignment, "for" loop header, or after\n"as" in a "with" statement or "except" clause. The "import" statement\nof the form "from ... import *" binds all names defined in the\nimported module, except those beginning with an underscore. This form\nmay only be used at the module level.\n\nA target occurring in a "del" statement is also considered bound for\nthis purpose (though the actual semantics are to unbind the name).\n\nEach assignment or import statement occurs within a block defined by a\nclass or function definition or at the module level (the top-level\ncode block).\n\nIf a name binding operation occurs anywhere within a code block, all\nuses of the name within the block are treated as references to the\ncurrent block. This can lead to errors when a name is used within a\nblock before it is bound. This rule is subtle. Python lacks\ndeclarations and allows name binding operations to occur anywhere\nwithin a code block. The local variables of a code block can be\ndetermined by scanning the entire text of the block for name binding\noperations.\n\nIf the "global" statement occurs within a block, all uses of the name\nspecified in the statement refer to the binding of that name in the\ntop-level namespace. Names are resolved in the top-level namespace by\nsearching the global namespace, i.e. the namespace of the module\ncontaining the code block, and the builtins namespace, the namespace\nof the module "builtins". The global namespace is searched first. If\nthe name is not found there, the builtins namespace is searched. The\nglobal statement must precede all uses of the name.\n\nThe builtins namespace associated with the execution of a code block\nis actually found by looking up the name "__builtins__" in its global\nnamespace; this should be a dictionary or a module (in the latter case\nthe module\'s dictionary is used). By default, when in the "__main__"\nmodule, "__builtins__" is the built-in module "builtins"; when in any\nother module, "__builtins__" is an alias for the dictionary of the\n"builtins" module itself. "__builtins__" can be set to a user-created\ndictionary to create a weak form of restricted execution.\n\n**CPython implementation detail:** Users should not touch\n"__builtins__"; it is strictly an implementation detail. Users\nwanting to override values in the builtins namespace should "import"\nthe "builtins" module and modify its attributes appropriately.\n\nThe namespace for a module is automatically created the first time a\nmodule is imported. The main module for a script is always called\n"__main__".\n\nThe "global" statement has the same scope as a name binding operation\nin the same block. If the nearest enclosing scope for a free variable\ncontains a global statement, the free variable is treated as a global.\n\nA class definition is an executable statement that may use and define\nnames. These references follow the normal rules for name resolution.\nThe namespace of the class definition becomes the attribute dictionary\nof the class. Names defined at the class scope are not visible in\nmethods.\n\n\nInteraction with dynamic features\n---------------------------------\n\nThere are several cases where Python statements are illegal when used\nin conjunction with nested scopes that contain free variables.\n\nIf a variable is referenced in an enclosing scope, it is illegal to\ndelete the name. An error will be reported at compile time.\n\nIf the wild card form of import --- "import *" --- is used in a\nfunction and the function contains or is a nested block with free\nvariables, the compiler will raise a "SyntaxError".\n\nThe "eval()" and "exec()" functions do not have access to the full\nenvironment for resolving names. Names may be resolved in the local\nand global namespaces of the caller. Free variables are not resolved\nin the nearest enclosing namespace, but in the global namespace. [1]\nThe "exec()" and "eval()" functions have optional arguments to\noverride the global and local namespace. If only one namespace is\nspecified, it is used for both.\n\n\nExceptions\n==========\n\nExceptions are a means of breaking out of the normal flow of control\nof a code block in order to handle errors or other exceptional\nconditions. An exception is *raised* at the point where the error is\ndetected; it may be *handled* by the surrounding code block or by any\ncode block that directly or indirectly invoked the code block where\nthe error occurred.\n\nThe Python interpreter raises an exception when it detects a run-time\nerror (such as division by zero). A Python program can also\nexplicitly raise an exception with the "raise" statement. Exception\nhandlers are specified with the "try" ... "except" statement. The\n"finally" clause of such a statement can be used to specify cleanup\ncode which does not handle the exception, but is executed whether an\nexception occurred or not in the preceding code.\n\nPython uses the "termination" model of error handling: an exception\nhandler can find out what happened and continue execution at an outer\nlevel, but it cannot repair the cause of the error and retry the\nfailing operation (except by re-entering the offending piece of code\nfrom the top).\n\nWhen an exception is not handled at all, the interpreter terminates\nexecution of the program, or returns to its interactive main loop. In\neither case, it prints a stack backtrace, except when the exception is\n"SystemExit".\n\nExceptions are identified by class instances. The "except" clause is\nselected depending on the class of the instance: it must reference the\nclass of the instance or a base class thereof. The instance can be\nreceived by the handler and can carry additional information about the\nexceptional condition.\n\nNote: Exception messages are not part of the Python API. Their contents\n may change from one version of Python to the next without warning\n and should not be relied on by code which will run under multiple\n versions of the interpreter.\n\nSee also the description of the "try" statement in section *The try\nstatement* and "raise" statement in section *The raise statement*.\n\n-[ Footnotes ]-\n\n[1] This limitation occurs because the code that is executed by these\n operations is not available at the time the module is compiled.\n', + 'exceptions': '\nExceptions\n**********\n\nExceptions are a means of breaking out of the normal flow of control\nof a code block in order to handle errors or other exceptional\nconditions. An exception is *raised* at the point where the error is\ndetected; it may be *handled* by the surrounding code block or by any\ncode block that directly or indirectly invoked the code block where\nthe error occurred.\n\nThe Python interpreter raises an exception when it detects a run-time\nerror (such as division by zero). A Python program can also\nexplicitly raise an exception with the "raise" statement. Exception\nhandlers are specified with the "try" ... "except" statement. The\n"finally" clause of such a statement can be used to specify cleanup\ncode which does not handle the exception, but is executed whether an\nexception occurred or not in the preceding code.\n\nPython uses the "termination" model of error handling: an exception\nhandler can find out what happened and continue execution at an outer\nlevel, but it cannot repair the cause of the error and retry the\nfailing operation (except by re-entering the offending piece of code\nfrom the top).\n\nWhen an exception is not handled at all, the interpreter terminates\nexecution of the program, or returns to its interactive main loop. In\neither case, it prints a stack backtrace, except when the exception is\n"SystemExit".\n\nExceptions are identified by class instances. The "except" clause is\nselected depending on the class of the instance: it must reference the\nclass of the instance or a base class thereof. The instance can be\nreceived by the handler and can carry additional information about the\nexceptional condition.\n\nNote: Exception messages are not part of the Python API. Their\n contents may change from one version of Python to the next without\n warning and should not be relied on by code which will run under\n multiple versions of the interpreter.\n\nSee also the description of the "try" statement in section *The try\nstatement* and "raise" statement in section *The raise statement*.\n\n-[ Footnotes ]-\n\n[1] This limitation occurs because the code that is executed by\n these operations is not available at the time the module is\n compiled.\n', + 'execmodel': '\nExecution model\n***************\n\n\nNaming and binding\n==================\n\n*Names* refer to objects. Names are introduced by name binding\noperations. Each occurrence of a name in the program text refers to\nthe *binding* of that name established in the innermost function block\ncontaining the use.\n\nA *block* is a piece of Python program text that is executed as a\nunit. The following are blocks: a module, a function body, and a class\ndefinition. Each command typed interactively is a block. A script\nfile (a file given as standard input to the interpreter or specified\non the interpreter command line the first argument) is a code block.\nA script command (a command specified on the interpreter command line\nwith the \'**-c**\' option) is a code block. The string argument passed\nto the built-in functions "eval()" and "exec()" is a code block.\n\nA code block is executed in an *execution frame*. A frame contains\nsome administrative information (used for debugging) and determines\nwhere and how execution continues after the code block\'s execution has\ncompleted.\n\nA *scope* defines the visibility of a name within a block. If a local\nvariable is defined in a block, its scope includes that block. If the\ndefinition occurs in a function block, the scope extends to any blocks\ncontained within the defining one, unless a contained block introduces\na different binding for the name. The scope of names defined in a\nclass block is limited to the class block; it does not extend to the\ncode blocks of methods -- this includes comprehensions and generator\nexpressions since they are implemented using a function scope. This\nmeans that the following will fail:\n\n class A:\n a = 42\n b = list(a + i for i in range(10))\n\nWhen a name is used in a code block, it is resolved using the nearest\nenclosing scope. The set of all such scopes visible to a code block\nis called the block\'s *environment*.\n\nIf a name is bound in a block, it is a local variable of that block,\nunless declared as "nonlocal". If a name is bound at the module\nlevel, it is a global variable. (The variables of the module code\nblock are local and global.) If a variable is used in a code block\nbut not defined there, it is a *free variable*.\n\nWhen a name is not found at all, a "NameError" exception is raised.\nIf the name refers to a local variable that has not been bound, a\n"UnboundLocalError" exception is raised. "UnboundLocalError" is a\nsubclass of "NameError".\n\nThe following constructs bind names: formal parameters to functions,\n"import" statements, class and function definitions (these bind the\nclass or function name in the defining block), and targets that are\nidentifiers if occurring in an assignment, "for" loop header, or after\n"as" in a "with" statement or "except" clause. The "import" statement\nof the form "from ... import *" binds all names defined in the\nimported module, except those beginning with an underscore. This form\nmay only be used at the module level.\n\nA target occurring in a "del" statement is also considered bound for\nthis purpose (though the actual semantics are to unbind the name).\n\nEach assignment or import statement occurs within a block defined by a\nclass or function definition or at the module level (the top-level\ncode block).\n\nIf a name binding operation occurs anywhere within a code block, all\nuses of the name within the block are treated as references to the\ncurrent block. This can lead to errors when a name is used within a\nblock before it is bound. This rule is subtle. Python lacks\ndeclarations and allows name binding operations to occur anywhere\nwithin a code block. The local variables of a code block can be\ndetermined by scanning the entire text of the block for name binding\noperations.\n\nIf the "global" statement occurs within a block, all uses of the name\nspecified in the statement refer to the binding of that name in the\ntop-level namespace. Names are resolved in the top-level namespace by\nsearching the global namespace, i.e. the namespace of the module\ncontaining the code block, and the builtins namespace, the namespace\nof the module "builtins". The global namespace is searched first. If\nthe name is not found there, the builtins namespace is searched. The\nglobal statement must precede all uses of the name.\n\nThe builtins namespace associated with the execution of a code block\nis actually found by looking up the name "__builtins__" in its global\nnamespace; this should be a dictionary or a module (in the latter case\nthe module\'s dictionary is used). By default, when in the "__main__"\nmodule, "__builtins__" is the built-in module "builtins"; when in any\nother module, "__builtins__" is an alias for the dictionary of the\n"builtins" module itself. "__builtins__" can be set to a user-created\ndictionary to create a weak form of restricted execution.\n\n**CPython implementation detail:** Users should not touch\n"__builtins__"; it is strictly an implementation detail. Users\nwanting to override values in the builtins namespace should "import"\nthe "builtins" module and modify its attributes appropriately.\n\nThe namespace for a module is automatically created the first time a\nmodule is imported. The main module for a script is always called\n"__main__".\n\nThe "global" statement has the same scope as a name binding operation\nin the same block. If the nearest enclosing scope for a free variable\ncontains a global statement, the free variable is treated as a global.\n\nA class definition is an executable statement that may use and define\nnames. These references follow the normal rules for name resolution.\nThe namespace of the class definition becomes the attribute dictionary\nof the class. Names defined at the class scope are not visible in\nmethods.\n\n\nInteraction with dynamic features\n---------------------------------\n\nThere are several cases where Python statements are illegal when used\nin conjunction with nested scopes that contain free variables.\n\nIf a variable is referenced in an enclosing scope, it is illegal to\ndelete the name. An error will be reported at compile time.\n\nIf the wild card form of import --- "import *" --- is used in a\nfunction and the function contains or is a nested block with free\nvariables, the compiler will raise a "SyntaxError".\n\nThe "eval()" and "exec()" functions do not have access to the full\nenvironment for resolving names. Names may be resolved in the local\nand global namespaces of the caller. Free variables are not resolved\nin the nearest enclosing namespace, but in the global namespace. [1]\nThe "exec()" and "eval()" functions have optional arguments to\noverride the global and local namespace. If only one namespace is\nspecified, it is used for both.\n\n\nExceptions\n==========\n\nExceptions are a means of breaking out of the normal flow of control\nof a code block in order to handle errors or other exceptional\nconditions. An exception is *raised* at the point where the error is\ndetected; it may be *handled* by the surrounding code block or by any\ncode block that directly or indirectly invoked the code block where\nthe error occurred.\n\nThe Python interpreter raises an exception when it detects a run-time\nerror (such as division by zero). A Python program can also\nexplicitly raise an exception with the "raise" statement. Exception\nhandlers are specified with the "try" ... "except" statement. The\n"finally" clause of such a statement can be used to specify cleanup\ncode which does not handle the exception, but is executed whether an\nexception occurred or not in the preceding code.\n\nPython uses the "termination" model of error handling: an exception\nhandler can find out what happened and continue execution at an outer\nlevel, but it cannot repair the cause of the error and retry the\nfailing operation (except by re-entering the offending piece of code\nfrom the top).\n\nWhen an exception is not handled at all, the interpreter terminates\nexecution of the program, or returns to its interactive main loop. In\neither case, it prints a stack backtrace, except when the exception is\n"SystemExit".\n\nExceptions are identified by class instances. The "except" clause is\nselected depending on the class of the instance: it must reference the\nclass of the instance or a base class thereof. The instance can be\nreceived by the handler and can carry additional information about the\nexceptional condition.\n\nNote: Exception messages are not part of the Python API. Their\n contents may change from one version of Python to the next without\n warning and should not be relied on by code which will run under\n multiple versions of the interpreter.\n\nSee also the description of the "try" statement in section *The try\nstatement* and "raise" statement in section *The raise statement*.\n\n-[ Footnotes ]-\n\n[1] This limitation occurs because the code that is executed by\n these operations is not available at the time the module is\n compiled.\n', 'exprlists': '\nExpression lists\n****************\n\n expression_list ::= expression ( "," expression )* [","]\n\nAn expression list containing at least one comma yields a tuple. The\nlength of the tuple is the number of expressions in the list. The\nexpressions are evaluated from left to right.\n\nThe trailing comma is required only to create a single tuple (a.k.a. a\n*singleton*); it is optional in all other cases. A single expression\nwithout a trailing comma doesn\'t create a tuple, but rather yields the\nvalue of that expression. (To create an empty tuple, use an empty pair\nof parentheses: "()".)\n', 'floating': '\nFloating point literals\n***********************\n\nFloating point literals are described by the following lexical\ndefinitions:\n\n floatnumber ::= pointfloat | exponentfloat\n pointfloat ::= [intpart] fraction | intpart "."\n exponentfloat ::= (intpart | pointfloat) exponent\n intpart ::= digit+\n fraction ::= "." digit+\n exponent ::= ("e" | "E") ["+" | "-"] digit+\n\nNote that the integer and exponent parts are always interpreted using\nradix 10. For example, "077e010" is legal, and denotes the same number\nas "77e10". The allowed range of floating point literals is\nimplementation-dependent. Some examples of floating point literals:\n\n 3.14 10. .001 1e100 3.14e-10 0e0\n\nNote that numeric literals do not include a sign; a phrase like "-1"\nis actually an expression composed of the unary operator "-" and the\nliteral "1".\n', - 'for': '\nThe "for" statement\n*******************\n\nThe "for" statement is used to iterate over the elements of a sequence\n(such as a string, tuple or list) or other iterable object:\n\n for_stmt ::= "for" target_list "in" expression_list ":" suite\n ["else" ":" suite]\n\nThe expression list is evaluated once; it should yield an iterable\nobject. An iterator is created for the result of the\n"expression_list". The suite is then executed once for each item\nprovided by the iterator, in the order of ascending indices. Each\nitem in turn is assigned to the target list using the standard rules\nfor assignments (see *Assignment statements*), and then the suite is\nexecuted. When the items are exhausted (which is immediately when the\nsequence is empty or an iterator raises a "StopIteration" exception),\nthe suite in the "else" clause, if present, is executed, and the loop\nterminates.\n\nA "break" statement executed in the first suite terminates the loop\nwithout executing the "else" clause\'s suite. A "continue" statement\nexecuted in the first suite skips the rest of the suite and continues\nwith the next item, or with the "else" clause if there was no next\nitem.\n\nThe suite may assign to the variable(s) in the target list; this does\nnot affect the next item assigned to it.\n\nNames in the target list are not deleted when the loop is finished,\nbut if the sequence is empty, it will not have been assigned to at all\nby the loop. Hint: the built-in function "range()" returns an\niterator of integers suitable to emulate the effect of Pascal\'s "for i\n:= a to b do"; e.g., "list(range(3))" returns the list "[0, 1, 2]".\n\nNote: There is a subtlety when the sequence is being modified by the loop\n (this can only occur for mutable sequences, i.e. lists). An\n internal counter is used to keep track of which item is used next,\n and this is incremented on each iteration. When this counter has\n reached the length of the sequence the loop terminates. This means\n that if the suite deletes the current (or a previous) item from the\n sequence, the next item will be skipped (since it gets the index of\n the current item which has already been treated). Likewise, if the\n suite inserts an item in the sequence before the current item, the\n current item will be treated again the next time through the loop.\n This can lead to nasty bugs that can be avoided by making a\n temporary copy using a slice of the whole sequence, e.g.,\n\n for x in a[:]:\n if x < 0: a.remove(x)\n', + 'for': '\nThe "for" statement\n*******************\n\nThe "for" statement is used to iterate over the elements of a sequence\n(such as a string, tuple or list) or other iterable object:\n\n for_stmt ::= "for" target_list "in" expression_list ":" suite\n ["else" ":" suite]\n\nThe expression list is evaluated once; it should yield an iterable\nobject. An iterator is created for the result of the\n"expression_list". The suite is then executed once for each item\nprovided by the iterator, in the order of ascending indices. Each\nitem in turn is assigned to the target list using the standard rules\nfor assignments (see *Assignment statements*), and then the suite is\nexecuted. When the items are exhausted (which is immediately when the\nsequence is empty or an iterator raises a "StopIteration" exception),\nthe suite in the "else" clause, if present, is executed, and the loop\nterminates.\n\nA "break" statement executed in the first suite terminates the loop\nwithout executing the "else" clause\'s suite. A "continue" statement\nexecuted in the first suite skips the rest of the suite and continues\nwith the next item, or with the "else" clause if there was no next\nitem.\n\nThe suite may assign to the variable(s) in the target list; this does\nnot affect the next item assigned to it.\n\nNames in the target list are not deleted when the loop is finished,\nbut if the sequence is empty, it will not have been assigned to at all\nby the loop. Hint: the built-in function "range()" returns an\niterator of integers suitable to emulate the effect of Pascal\'s "for i\n:= a to b do"; e.g., "list(range(3))" returns the list "[0, 1, 2]".\n\nNote: There is a subtlety when the sequence is being modified by the\n loop (this can only occur for mutable sequences, i.e. lists). An\n internal counter is used to keep track of which item is used next,\n and this is incremented on each iteration. When this counter has\n reached the length of the sequence the loop terminates. This means\n that if the suite deletes the current (or a previous) item from the\n sequence, the next item will be skipped (since it gets the index of\n the current item which has already been treated). Likewise, if the\n suite inserts an item in the sequence before the current item, the\n current item will be treated again the next time through the loop.\n This can lead to nasty bugs that can be avoided by making a\n temporary copy using a slice of the whole sequence, e.g.,\n\n for x in a[:]:\n if x < 0: a.remove(x)\n', 'formatstrings': '\nFormat String Syntax\n********************\n\nThe "str.format()" method and the "Formatter" class share the same\nsyntax for format strings (although in the case of "Formatter",\nsubclasses can define their own format string syntax).\n\nFormat strings contain "replacement fields" surrounded by curly braces\n"{}". Anything that is not contained in braces is considered literal\ntext, which is copied unchanged to the output. If you need to include\na brace character in the literal text, it can be escaped by doubling:\n"{{" and "}}".\n\nThe grammar for a replacement field is as follows:\n\n replacement_field ::= "{" [field_name] ["!" conversion] [":" format_spec] "}"\n field_name ::= arg_name ("." attribute_name | "[" element_index "]")*\n arg_name ::= [identifier | integer]\n attribute_name ::= identifier\n element_index ::= integer | index_string\n index_string ::= <any source character except "]"> +\n conversion ::= "r" | "s" | "a"\n format_spec ::= <described in the next section>\n\nIn less formal terms, the replacement field can start with a\n*field_name* that specifies the object whose value is to be formatted\nand inserted into the output instead of the replacement field. The\n*field_name* is optionally followed by a *conversion* field, which is\npreceded by an exclamation point "\'!\'", and a *format_spec*, which is\npreceded by a colon "\':\'". These specify a non-default format for the\nreplacement value.\n\nSee also the *Format Specification Mini-Language* section.\n\nThe *field_name* itself begins with an *arg_name* that is either a\nnumber or a keyword. If it\'s a number, it refers to a positional\nargument, and if it\'s a keyword, it refers to a named keyword\nargument. If the numerical arg_names in a format string are 0, 1, 2,\n... in sequence, they can all be omitted (not just some) and the\nnumbers 0, 1, 2, ... will be automatically inserted in that order.\nBecause *arg_name* is not quote-delimited, it is not possible to\nspecify arbitrary dictionary keys (e.g., the strings "\'10\'" or\n"\':-]\'") within a format string. The *arg_name* can be followed by any\nnumber of index or attribute expressions. An expression of the form\n"\'.name\'" selects the named attribute using "getattr()", while an\nexpression of the form "\'[index]\'" does an index lookup using\n"__getitem__()".\n\nChanged in version 3.1: The positional argument specifiers can be\nomitted, so "\'{} {}\'" is equivalent to "\'{0} {1}\'".\n\nSome simple format string examples:\n\n "First, thou shalt count to {0}" # References first positional argument\n "Bring me a {}" # Implicitly references the first positional argument\n "From {} to {}" # Same as "From {0} to {1}"\n "My quest is {name}" # References keyword argument \'name\'\n "Weight in tons {0.weight}" # \'weight\' attribute of first positional arg\n "Units destroyed: {players[0]}" # First element of keyword argument \'players\'.\n\nThe *conversion* field causes a type coercion before formatting.\nNormally, the job of formatting a value is done by the "__format__()"\nmethod of the value itself. However, in some cases it is desirable to\nforce a type to be formatted as a string, overriding its own\ndefinition of formatting. By converting the value to a string before\ncalling "__format__()", the normal formatting logic is bypassed.\n\nThree conversion flags are currently supported: "\'!s\'" which calls\n"str()" on the value, "\'!r\'" which calls "repr()" and "\'!a\'" which\ncalls "ascii()".\n\nSome examples:\n\n "Harold\'s a clever {0!s}" # Calls str() on the argument first\n "Bring out the holy {name!r}" # Calls repr() on the argument first\n "More {!a}" # Calls ascii() on the argument first\n\nThe *format_spec* field contains a specification of how the value\nshould be presented, including such details as field width, alignment,\npadding, decimal precision and so on. Each value type can define its\nown "formatting mini-language" or interpretation of the *format_spec*.\n\nMost built-in types support a common formatting mini-language, which\nis described in the next section.\n\nA *format_spec* field can also include nested replacement fields\nwithin it. These nested replacement fields can contain only a field\nname; conversion flags and format specifications are not allowed. The\nreplacement fields within the format_spec are substituted before the\n*format_spec* string is interpreted. This allows the formatting of a\nvalue to be dynamically specified.\n\nSee the *Format examples* section for some examples.\n\n\nFormat Specification Mini-Language\n==================================\n\n"Format specifications" are used within replacement fields contained\nwithin a format string to define how individual values are presented\n(see *Format String Syntax*). They can also be passed directly to the\nbuilt-in "format()" function. Each formattable type may define how\nthe format specification is to be interpreted.\n\nMost built-in types implement the following options for format\nspecifications, although some of the formatting options are only\nsupported by the numeric types.\n\nA general convention is that an empty format string ("""") produces\nthe same result as if you had called "str()" on the value. A non-empty\nformat string typically modifies the result.\n\nThe general form of a *standard format specifier* is:\n\n format_spec ::= [[fill]align][sign][#][0][width][,][.precision][type]\n fill ::= <any character>\n align ::= "<" | ">" | "=" | "^"\n sign ::= "+" | "-" | " "\n width ::= integer\n precision ::= integer\n type ::= "b" | "c" | "d" | "e" | "E" | "f" | "F" | "g" | "G" | "n" | "o" | "s" | "x" | "X" | "%"\n\nIf a valid *align* value is specified, it can be preceded by a *fill*\ncharacter that can be any character and defaults to a space if\nomitted. Note that it is not possible to use "{" and "}" as *fill*\nchar while using the "str.format()" method; this limitation however\ndoesn\'t affect the "format()" function.\n\nThe meaning of the various alignment options is as follows:\n\n +-----------+------------------------------------------------------------+\n | Option | Meaning |\n +===========+============================================================+\n | "\'<\'" | Forces the field to be left-aligned within the available |\n +-----------+------------------------------------------------------------+\n | "\'>\'" | Forces the field to be right-aligned within the available |\n +-----------+------------------------------------------------------------+\n | "\'=\'" | Forces the padding to be placed after the sign (if any) |\n +-----------+------------------------------------------------------------+\n | "\'^\'" | Forces the field to be centered within the available |\n +-----------+------------------------------------------------------------+\n\nNote that unless a minimum field width is defined, the field width\nwill always be the same size as the data to fill it, so that the\nalignment option has no meaning in this case.\n\nThe *sign* option is only valid for number types, and can be one of\nthe following:\n\n +-----------+------------------------------------------------------------+\n | Option | Meaning |\n +===========+============================================================+\n | "\'+\'" | indicates that a sign should be used for both positive as |\n +-----------+------------------------------------------------------------+\n | "\'-\'" | indicates that a sign should be used only for negative |\n +-----------+------------------------------------------------------------+\n | space | indicates that a leading space should be used on positive |\n +-----------+------------------------------------------------------------+\n\nThe "\'#\'" option causes the "alternate form" to be used for the\nconversion. The alternate form is defined differently for different\ntypes. This option is only valid for integer, float, complex and\nDecimal types. For integers, when binary, octal, or hexadecimal output\nis used, this option adds the prefix respective "\'0b\'", "\'0o\'", or\n"\'0x\'" to the output value. For floats, complex and Decimal the\nalternate form causes the result of the conversion to always contain a\ndecimal-point character, even if no digits follow it. Normally, a\ndecimal-point character appears in the result of these conversions\nonly if a digit follows it. In addition, for "\'g\'" and "\'G\'"\nconversions, trailing zeros are not removed from the result.\n\nThe "\',\'" option signals the use of a comma for a thousands separator.\nFor a locale aware separator, use the "\'n\'" integer presentation type\ninstead.\n\nChanged in version 3.1: Added the "\',\'" option (see also **PEP 378**).\n\n*width* is a decimal integer defining the minimum field width. If not\nspecified, then the field width will be determined by the content.\n\nPreceding the *width* field by a zero ("\'0\'") character enables sign-\naware zero-padding for numeric types. This is equivalent to a *fill*\ncharacter of "\'0\'" with an *alignment* type of "\'=\'".\n\nThe *precision* is a decimal number indicating how many digits should\nbe displayed after the decimal point for a floating point value\nformatted with "\'f\'" and "\'F\'", or before and after the decimal point\nfor a floating point value formatted with "\'g\'" or "\'G\'". For non-\nnumber types the field indicates the maximum field size - in other\nwords, how many characters will be used from the field content. The\n*precision* is not allowed for integer values.\n\nFinally, the *type* determines how the data should be presented.\n\nThe available string presentation types are:\n\n +-----------+------------------------------------------------------------+\n | Type | Meaning |\n +===========+============================================================+\n | "\'s\'" | String format. This is the default type for strings and |\n +-----------+------------------------------------------------------------+\n | None | The same as "\'s\'". |\n +-----------+------------------------------------------------------------+\n\nThe available integer presentation types are:\n\n +-----------+------------------------------------------------------------+\n | Type | Meaning |\n +===========+============================================================+\n | "\'b\'" | Binary format. Outputs the number in base 2. |\n +-----------+------------------------------------------------------------+\n | "\'c\'" | Character. Converts the integer to the corresponding |\n +-----------+------------------------------------------------------------+\n | "\'d\'" | Decimal Integer. Outputs the number in base 10. |\n +-----------+------------------------------------------------------------+\n | "\'o\'" | Octal format. Outputs the number in base 8. |\n +-----------+------------------------------------------------------------+\n | "\'x\'" | Hex format. Outputs the number in base 16, using lower- |\n +-----------+------------------------------------------------------------+\n | "\'X\'" | Hex format. Outputs the number in base 16, using upper- |\n +-----------+------------------------------------------------------------+\n | "\'n\'" | Number. This is the same as "\'d\'", except that it uses the |\n +-----------+------------------------------------------------------------+\n | None | The same as "\'d\'". |\n +-----------+------------------------------------------------------------+\n\nIn addition to the above presentation types, integers can be formatted\nwith the floating point presentation types listed below (except "\'n\'"\nand None). When doing so, "float()" is used to convert the integer to\na floating point number before formatting.\n\nThe available presentation types for floating point and decimal values\nare:\n\n +-----------+------------------------------------------------------------+\n | Type | Meaning |\n +===========+============================================================+\n | "\'e\'" | Exponent notation. Prints the number in scientific |\n +-----------+------------------------------------------------------------+\n | "\'E\'" | Exponent notation. Same as "\'e\'" except it uses an upper |\n +-----------+------------------------------------------------------------+\n | "\'f\'" | Fixed point. Displays the number as a fixed-point number. |\n +-----------+------------------------------------------------------------+\n | "\'F\'" | Fixed point. Same as "\'f\'", but converts "nan" to "NAN" |\n +-----------+------------------------------------------------------------+\n | "\'g\'" | General format. For a given precision "p >= 1", this |\n +-----------+------------------------------------------------------------+\n | "\'G\'" | General format. Same as "\'g\'" except switches to "\'E\'" if |\n +-----------+------------------------------------------------------------+\n | "\'n\'" | Number. This is the same as "\'g\'", except that it uses the |\n +-----------+------------------------------------------------------------+\n | "\'%\'" | Percentage. Multiplies the number by 100 and displays in |\n +-----------+------------------------------------------------------------+\n | None | Similar to "\'g\'", except with at least one digit past the |\n +-----------+------------------------------------------------------------+\n\n\nFormat examples\n===============\n\nThis section contains examples of the new format syntax and comparison\nwith the old "%"-formatting.\n\nIn most of the cases the syntax is similar to the old "%"-formatting,\nwith the addition of the "{}" and with ":" used instead of "%". For\nexample, "\'%03.2f\'" can be translated to "\'{:03.2f}\'".\n\nThe new format syntax also supports new and different options, shown\nin the follow examples.\n\nAccessing arguments by position:\n\n >>> \'{0}, {1}, {2}\'.format(\'a\', \'b\', \'c\')\n \'a, b, c\'\n >>> \'{}, {}, {}\'.format(\'a\', \'b\', \'c\') # 3.1+ only\n \'a, b, c\'\n >>> \'{2}, {1}, {0}\'.format(\'a\', \'b\', \'c\')\n \'c, b, a\'\n >>> \'{2}, {1}, {0}\'.format(*\'abc\') # unpacking argument sequence\n \'c, b, a\'\n >>> \'{0}{1}{0}\'.format(\'abra\', \'cad\') # arguments\' indices can be repeated\n \'abracadabra\'\n\nAccessing arguments by name:\n\n >>> \'Coordinates: {latitude}, {longitude}\'.format(latitude=\'37.24N\', longitude=\'-115.81W\')\n \'Coordinates: 37.24N, -115.81W\'\n >>> coord = {\'latitude\': \'37.24N\', \'longitude\': \'-115.81W\'}\n >>> \'Coordinates: {latitude}, {longitude}\'.format(**coord)\n \'Coordinates: 37.24N, -115.81W\'\n\nAccessing arguments\' attributes:\n\n >>> c = 3-5j\n >>> (\'The complex number {0} is formed from the real part {0.real} \'\n ... \'and the imaginary part {0.imag}.\').format(c)\n \'The complex number (3-5j) is formed from the real part 3.0 and the imaginary part -5.0.\'\n >>> class Point:\n ... def __init__(self, x, y):\n ... self.x, self.y = x, y\n ... def __str__(self):\n ... return \'Point({self.x}, {self.y})\'.format(self=self)\n ...\n >>> str(Point(4, 2))\n \'Point(4, 2)\'\n\nAccessing arguments\' items:\n\n >>> coord = (3, 5)\n >>> \'X: {0[0]}; Y: {0[1]}\'.format(coord)\n \'X: 3; Y: 5\'\n\nReplacing "%s" and "%r":\n\n >>> "repr() shows quotes: {!r}; str() doesn\'t: {!s}".format(\'test1\', \'test2\')\n "repr() shows quotes: \'test1\'; str() doesn\'t: test2"\n\nAligning the text and specifying a width:\n\n >>> \'{:<30}\'.format(\'left aligned\')\n \'left aligned \'\n >>> \'{:>30}\'.format(\'right aligned\')\n \' right aligned\'\n >>> \'{:^30}\'.format(\'centered\')\n \' centered \'\n >>> \'{:*^30}\'.format(\'centered\') # use \'*\' as a fill char\n \'***********centered***********\'\n\nReplacing "%+f", "%-f", and "% f" and specifying a sign:\n\n >>> \'{:+f}; {:+f}\'.format(3.14, -3.14) # show it always\n \'+3.140000; -3.140000\'\n >>> \'{: f}; {: f}\'.format(3.14, -3.14) # show a space for positive numbers\n \' 3.140000; -3.140000\'\n >>> \'{:-f}; {:-f}\'.format(3.14, -3.14) # show only the minus -- same as \'{:f}; {:f}\'\n \'3.140000; -3.140000\'\n\nReplacing "%x" and "%o" and converting the value to different bases:\n\n >>> # format also supports binary numbers\n >>> "int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}".format(42)\n \'int: 42; hex: 2a; oct: 52; bin: 101010\'\n >>> # with 0x, 0o, or 0b as prefix:\n >>> "int: {0:d}; hex: {0:#x}; oct: {0:#o}; bin: {0:#b}".format(42)\n \'int: 42; hex: 0x2a; oct: 0o52; bin: 0b101010\'\n\nUsing the comma as a thousands separator:\n\n >>> \'{:,}\'.format(1234567890)\n \'1,234,567,890\'\n\nExpressing a percentage:\n\n >>> points = 19\n >>> total = 22\n >>> \'Correct answers: {:.2%}\'.format(points/total)\n \'Correct answers: 86.36%\'\n\nUsing type-specific formatting:\n\n >>> import datetime\n >>> d = datetime.datetime(2010, 7, 4, 12, 15, 58)\n >>> \'{:%Y-%m-%d %H:%M:%S}\'.format(d)\n \'2010-07-04 12:15:58\'\n\nNesting arguments and more complex examples:\n\n >>> for align, text in zip(\'<^>\', [\'left\', \'center\', \'right\']):\n ... \'{0:{fill}{align}16}\'.format(text, fill=align, align=align)\n ...\n \'left<<<<<<<<<<<<\'\n \'^^^^^center^^^^^\'\n \'>>>>>>>>>>>right\'\n >>>\n >>> octets = [192, 168, 0, 1]\n >>> \'{:02X}{:02X}{:02X}{:02X}\'.format(*octets)\n \'C0A80001\'\n >>> int(_, 16)\n 3232235521\n >>>\n >>> width = 5\n >>> for num in range(5,12): #doctest: +NORMALIZE_WHITESPACE\n ... for base in \'dXob\':\n ... print(\'{0:{width}{base}}\'.format(num, base=base, width=width), end=\' \')\n ... print()\n ...\n 5 5 5 101\n 6 6 6 110\n 7 7 7 111\n 8 8 10 1000\n 9 9 11 1001\n 10 A 12 1010\n 11 B 13 1011\n', - 'function': '\nFunction definitions\n********************\n\nA function definition defines a user-defined function object (see\nsection *The standard type hierarchy*):\n\n funcdef ::= [decorators] "def" funcname "(" [parameter_list] ")" ["->" expression] ":" suite\n decorators ::= decorator+\n decorator ::= "@" dotted_name ["(" [parameter_list [","]] ")"] NEWLINE\n dotted_name ::= identifier ("." identifier)*\n parameter_list ::= (defparameter ",")*\n ( "*" [parameter] ("," defparameter)* ["," "**" parameter]\n | "**" parameter\n | defparameter [","] )\n parameter ::= identifier [":" expression]\n defparameter ::= parameter ["=" expression]\n funcname ::= identifier\n\nA function definition is an executable statement. Its execution binds\nthe function name in the current local namespace to a function object\n(a wrapper around the executable code for the function). This\nfunction object contains a reference to the current global namespace\nas the global namespace to be used when the function is called.\n\nThe function definition does not execute the function body; this gets\nexecuted only when the function is called. [3]\n\nA function definition may be wrapped by one or more *decorator*\nexpressions. Decorator expressions are evaluated when the function is\ndefined, in the scope that contains the function definition. The\nresult must be a callable, which is invoked with the function object\nas the only argument. The returned value is bound to the function name\ninstead of the function object. Multiple decorators are applied in\nnested fashion. For example, the following code\n\n @f1(arg)\n @f2\n def func(): pass\n\nis equivalent to\n\n def func(): pass\n func = f1(arg)(f2(func))\n\nWhen one or more *parameters* have the form *parameter* "="\n*expression*, the function is said to have "default parameter values."\nFor a parameter with a default value, the corresponding *argument* may\nbe omitted from a call, in which case the parameter\'s default value is\nsubstituted. If a parameter has a default value, all following\nparameters up until the ""*"" must also have a default value --- this\nis a syntactic restriction that is not expressed by the grammar.\n\n**Default parameter values are evaluated from left to right when the\nfunction definition is executed.** This means that the expression is\nevaluated once, when the function is defined, and that the same "pre-\ncomputed" value is used for each call. This is especially important\nto understand when a default parameter is a mutable object, such as a\nlist or a dictionary: if the function modifies the object (e.g. by\nappending an item to a list), the default value is in effect modified.\nThis is generally not what was intended. A way around this is to use\n"None" as the default, and explicitly test for it in the body of the\nfunction, e.g.:\n\n def whats_on_the_telly(penguin=None):\n if penguin is None:\n penguin = []\n penguin.append("property of the zoo")\n return penguin\n\nFunction call semantics are described in more detail in section\n*Calls*. A function call always assigns values to all parameters\nmentioned in the parameter list, either from position arguments, from\nkeyword arguments, or from default values. If the form\n""*identifier"" is present, it is initialized to a tuple receiving any\nexcess positional parameters, defaulting to the empty tuple. If the\nform ""**identifier"" is present, it is initialized to a new\ndictionary receiving any excess keyword arguments, defaulting to a new\nempty dictionary. Parameters after ""*"" or ""*identifier"" are\nkeyword-only parameters and may only be passed used keyword arguments.\n\nParameters may have annotations of the form "": expression"" following\nthe parameter name. Any parameter may have an annotation even those\nof the form "*identifier" or "**identifier". Functions may have\n"return" annotation of the form ""-> expression"" after the parameter\nlist. These annotations can be any valid Python expression and are\nevaluated when the function definition is executed. Annotations may\nbe evaluated in a different order than they appear in the source code.\nThe presence of annotations does not change the semantics of a\nfunction. The annotation values are available as values of a\ndictionary keyed by the parameters\' names in the "__annotations__"\nattribute of the function object.\n\nIt is also possible to create anonymous functions (functions not bound\nto a name), for immediate use in expressions. This uses lambda\nexpressions, described in section *Lambdas*. Note that the lambda\nexpression is merely a shorthand for a simplified function definition;\na function defined in a ""def"" statement can be passed around or\nassigned to another name just like a function defined by a lambda\nexpression. The ""def"" form is actually more powerful since it\nallows the execution of multiple statements and annotations.\n\n**Programmer\'s note:** Functions are first-class objects. A ""def""\nstatement executed inside a function definition defines a local\nfunction that can be returned or passed around. Free variables used\nin the nested function can access the local variables of the function\ncontaining the def. See section *Naming and binding* for details.\n\nSee also:\n\n **PEP 3107** - Function Annotations\n The original specification for function annotations.\n', + 'function': '\nFunction definitions\n********************\n\nA function definition defines a user-defined function object (see\nsection *The standard type hierarchy*):\n\n funcdef ::= [decorators] "def" funcname "(" [parameter_list] ")" ["->" expression] ":" suite\n decorators ::= decorator+\n decorator ::= "@" dotted_name ["(" [parameter_list [","]] ")"] NEWLINE\n dotted_name ::= identifier ("." identifier)*\n parameter_list ::= (defparameter ",")*\n ( "*" [parameter] ("," defparameter)* ["," "**" parameter]\n | "**" parameter\n | defparameter [","] )\n parameter ::= identifier [":" expression]\n defparameter ::= parameter ["=" expression]\n funcname ::= identifier\n\nA function definition is an executable statement. Its execution binds\nthe function name in the current local namespace to a function object\n(a wrapper around the executable code for the function). This\nfunction object contains a reference to the current global namespace\nas the global namespace to be used when the function is called.\n\nThe function definition does not execute the function body; this gets\nexecuted only when the function is called. [3]\n\nA function definition may be wrapped by one or more *decorator*\nexpressions. Decorator expressions are evaluated when the function is\ndefined, in the scope that contains the function definition. The\nresult must be a callable, which is invoked with the function object\nas the only argument. The returned value is bound to the function name\ninstead of the function object. Multiple decorators are applied in\nnested fashion. For example, the following code\n\n @f1(arg)\n @f2\n def func(): pass\n\nis equivalent to\n\n def func(): pass\n func = f1(arg)(f2(func))\n\nWhen one or more *parameters* have the form *parameter* "="\n*expression*, the function is said to have "default parameter values."\nFor a parameter with a default value, the corresponding *argument* may\nbe omitted from a call, in which case the parameter\'s default value is\nsubstituted. If a parameter has a default value, all following\nparameters up until the ""*"" must also have a default value --- this\nis a syntactic restriction that is not expressed by the grammar.\n\n**Default parameter values are evaluated from left to right when the\nfunction definition is executed.** This means that the expression is\nevaluated once, when the function is defined, and that the same "pre-\ncomputed" value is used for each call. This is especially important\nto understand when a default parameter is a mutable object, such as a\nlist or a dictionary: if the function modifies the object (e.g. by\nappending an item to a list), the default value is in effect modified.\nThis is generally not what was intended. A way around this is to use\n"None" as the default, and explicitly test for it in the body of the\nfunction, e.g.:\n\n def whats_on_the_telly(penguin=None):\n if penguin is None:\n penguin = []\n penguin.append("property of the zoo")\n return penguin\n\nFunction call semantics are described in more detail in section\n*Calls*. A function call always assigns values to all parameters\nmentioned in the parameter list, either from position arguments, from\nkeyword arguments, or from default values. If the form\n""*identifier"" is present, it is initialized to a tuple receiving any\nexcess positional parameters, defaulting to the empty tuple. If the\nform ""**identifier"" is present, it is initialized to a new\ndictionary receiving any excess keyword arguments, defaulting to a new\nempty dictionary. Parameters after ""*"" or ""*identifier"" are\nkeyword-only parameters and may only be passed used keyword arguments.\n\nParameters may have annotations of the form "": expression"" following\nthe parameter name. Any parameter may have an annotation even those\nof the form "*identifier" or "**identifier". Functions may have\n"return" annotation of the form ""-> expression"" after the parameter\nlist. These annotations can be any valid Python expression and are\nevaluated when the function definition is executed. Annotations may\nbe evaluated in a different order than they appear in the source code.\nThe presence of annotations does not change the semantics of a\nfunction. The annotation values are available as values of a\ndictionary keyed by the parameters\' names in the "__annotations__"\nattribute of the function object.\n\nIt is also possible to create anonymous functions (functions not bound\nto a name), for immediate use in expressions. This uses lambda\nexpressions, described in section *Lambdas*. Note that the lambda\nexpression is merely a shorthand for a simplified function definition;\na function defined in a ""def"" statement can be passed around or\nassigned to another name just like a function defined by a lambda\nexpression. The ""def"" form is actually more powerful since it\nallows the execution of multiple statements and annotations.\n\n**Programmer\'s note:** Functions are first-class objects. A ""def""\nstatement executed inside a function definition defines a local\nfunction that can be returned or passed around. Free variables used\nin the nested function can access the local variables of the function\ncontaining the def. See section *Naming and binding* for details.\n\nSee also: **PEP 3107** - Function Annotations\n\n The original specification for function annotations.\n', 'global': '\nThe "global" statement\n**********************\n\n global_stmt ::= "global" identifier ("," identifier)*\n\nThe "global" statement is a declaration which holds for the entire\ncurrent code block. It means that the listed identifiers are to be\ninterpreted as globals. It would be impossible to assign to a global\nvariable without "global", although free variables may refer to\nglobals without being declared global.\n\nNames listed in a "global" statement must not be used in the same code\nblock textually preceding that "global" statement.\n\nNames listed in a "global" statement must not be defined as formal\nparameters or in a "for" loop control target, "class" definition,\nfunction definition, or "import" statement.\n\n**CPython implementation detail:** The current implementation does not\nenforce the latter two restrictions, but programs should not abuse\nthis freedom, as future implementations may enforce them or silently\nchange the meaning of the program.\n\n**Programmer\'s note:** the "global" is a directive to the parser. It\napplies only to code parsed at the same time as the "global"\nstatement. In particular, a "global" statement contained in a string\nor code object supplied to the built-in "exec()" function does not\naffect the code block *containing* the function call, and code\ncontained in such a string is unaffected by "global" statements in the\ncode containing the function call. The same applies to the "eval()"\nand "compile()" functions.\n', 'id-classes': '\nReserved classes of identifiers\n*******************************\n\nCertain classes of identifiers (besides keywords) have special\nmeanings. These classes are identified by the patterns of leading and\ntrailing underscore characters:\n\n"_*"\n Not imported by "from module import *". The special identifier "_"\n is used in the interactive interpreter to store the result of the\n last evaluation; it is stored in the "builtins" module. When not\n in interactive mode, "_" has no special meaning and is not defined.\n See section *The import statement*.\n\n Note: The name "_" is often used in conjunction with\n internationalization; refer to the documentation for the\n "gettext" module for more information on this convention.\n\n"__*__"\n System-defined names. These names are defined by the interpreter\n and its implementation (including the standard library). Current\n system names are discussed in the *Special method names* section\n and elsewhere. More will likely be defined in future versions of\n Python. *Any* use of "__*__" names, in any context, that does not\n follow explicitly documented use, is subject to breakage without\n warning.\n\n"__*"\n Class-private names. Names in this category, when used within the\n context of a class definition, are re-written to use a mangled form\n to help avoid name clashes between "private" attributes of base and\n derived classes. See section *Identifiers (Names)*.\n', 'identifiers': '\nIdentifiers and keywords\n************************\n\nIdentifiers (also referred to as *names*) are described by the\nfollowing lexical definitions.\n\nThe syntax of identifiers in Python is based on the Unicode standard\nannex UAX-31, with elaboration and changes as defined below; see also\n**PEP 3131** for further details.\n\nWithin the ASCII range (U+0001..U+007F), the valid characters for\nidentifiers are the same as in Python 2.x: the uppercase and lowercase\nletters "A" through "Z", the underscore "_" and, except for the first\ncharacter, the digits "0" through "9".\n\nPython 3.0 introduces additional characters from outside the ASCII\nrange (see **PEP 3131**). For these characters, the classification\nuses the version of the Unicode Character Database as included in the\n"unicodedata" module.\n\nIdentifiers are unlimited in length. Case is significant.\n\n identifier ::= xid_start xid_continue*\n id_start ::= <all characters in general categories Lu, Ll, Lt, Lm, Lo, Nl, the underscore, and characters with the Other_ID_Start property>\n id_continue ::= <all characters in id_start, plus characters in the categories Mn, Mc, Nd, Pc and others with the Other_ID_Continue property>\n xid_start ::= <all characters in id_start whose NFKC normalization is in "id_start xid_continue*">\n xid_continue ::= <all characters in id_continue whose NFKC normalization is in "id_continue*">\n\nThe Unicode category codes mentioned above stand for:\n\n* *Lu* - uppercase letters\n\n* *Ll* - lowercase letters\n\n* *Lt* - titlecase letters\n\n* *Lm* - modifier letters\n\n* *Lo* - other letters\n\n* *Nl* - letter numbers\n\n* *Mn* - nonspacing marks\n\n* *Mc* - spacing combining marks\n\n* *Nd* - decimal numbers\n\n* *Pc* - connector punctuations\n\n* *Other_ID_Start* - explicit list of characters in PropList.txt to\n support backwards compatibility\n\n* *Other_ID_Continue* - likewise\n\nAll identifiers are converted into the normal form NFKC while parsing;\ncomparison of identifiers is based on NFKC.\n\nA non-normative HTML file listing all valid identifier characters for\nUnicode 4.1 can be found at http://www.dcl.hpi.uni-\npotsdam.de/home/loewis/table-3131.html.\n\n\nKeywords\n========\n\nThe following identifiers are used as reserved words, or *keywords* of\nthe language, and cannot be used as ordinary identifiers. They must\nbe spelled exactly as written here:\n\n False class finally is return\n None continue for lambda try\n True def from nonlocal while\n and del global not with\n as elif if or yield\n assert else import pass\n break except in raise\n\n\nReserved classes of identifiers\n===============================\n\nCertain classes of identifiers (besides keywords) have special\nmeanings. These classes are identified by the patterns of leading and\ntrailing underscore characters:\n\n"_*"\n Not imported by "from module import *". The special identifier "_"\n is used in the interactive interpreter to store the result of the\n last evaluation; it is stored in the "builtins" module. When not\n in interactive mode, "_" has no special meaning and is not defined.\n See section *The import statement*.\n\n Note: The name "_" is often used in conjunction with\n internationalization; refer to the documentation for the\n "gettext" module for more information on this convention.\n\n"__*__"\n System-defined names. These names are defined by the interpreter\n and its implementation (including the standard library). Current\n system names are discussed in the *Special method names* section\n and elsewhere. More will likely be defined in future versions of\n Python. *Any* use of "__*__" names, in any context, that does not\n follow explicitly documented use, is subject to breakage without\n warning.\n\n"__*"\n Class-private names. Names in this category, when used within the\n context of a class definition, are re-written to use a mangled form\n to help avoid name clashes between "private" attributes of base and\n derived classes. See section *Identifiers (Names)*.\n', 'if': '\nThe "if" statement\n******************\n\nThe "if" statement is used for conditional execution:\n\n if_stmt ::= "if" expression ":" suite\n ( "elif" expression ":" suite )*\n ["else" ":" suite]\n\nIt selects exactly one of the suites by evaluating the expressions one\nby one until one is found to be true (see section *Boolean operations*\nfor the definition of true and false); then that suite is executed\n(and no other part of the "if" statement is executed or evaluated).\nIf all expressions are false, the suite of the "else" clause, if\npresent, is executed.\n', 'imaginary': '\nImaginary literals\n******************\n\nImaginary literals are described by the following lexical definitions:\n\n imagnumber ::= (floatnumber | intpart) ("j" | "J")\n\nAn imaginary literal yields a complex number with a real part of 0.0.\nComplex numbers are represented as a pair of floating point numbers\nand have the same restrictions on their range. To create a complex\nnumber with a nonzero real part, add a floating point number to it,\ne.g., "(3+4j)". Some examples of imaginary literals:\n\n 3.14j 10.j 10j .001j 1e100j 3.14e-10j\n', - 'import': '\nThe "import" statement\n**********************\n\n import_stmt ::= "import" module ["as" name] ( "," module ["as" name] )*\n | "from" relative_module "import" identifier ["as" name]\n ( "," identifier ["as" name] )*\n | "from" relative_module "import" "(" identifier ["as" name]\n ( "," identifier ["as" name] )* [","] ")"\n | "from" module "import" "*"\n module ::= (identifier ".")* identifier\n relative_module ::= "."* module | "."+\n name ::= identifier\n\nThe basic import statement (no "from" clause) is executed in two\nsteps:\n\n1. find a module, loading and initializing it if necessary\n\n2. define a name or names in the local namespace for the scope where\n the "import" statement occurs.\n\nWhen the statement contains multiple clauses (separated by commas) the\ntwo steps are carried out separately for each clause, just as though\nthe clauses had been separated out into individiual import statements.\n\nThe details of the first step, finding and loading modules is\ndescribed in greater detail in the section on the *import system*,\nwhich also describes the various types of packages and modules that\ncan be imported, as well as all the hooks that can be used to\ncustomize the import system. Note that failures in this step may\nindicate either that the module could not be located, *or* that an\nerror occurred while initializing the module, which includes execution\nof the module\'s code.\n\nIf the requested module is retrieved successfully, it will be made\navailable in the local namespace in one of three ways:\n\n* If the module name is followed by "as", then the name following "as"\n is bound directly to the imported module.\n\n* If no other name is specified, and the module being imported is a\n top level module, the module\'s name is bound in the local namespace\n as a reference to the imported module\n\n* If the module being imported is *not* a top level module, then the\n name of the top level package that contains the module is bound in\n the local namespace as a reference to the top level package. The\n imported module must be accessed using its full qualified name\n rather than directly\n\nThe "from" form uses a slightly more complex process:\n\n1. find the module specified in the "from" clause loading and\n initializing it if necessary;\n\n2. for each of the identifiers specified in the "import" clauses:\n\n 1. check if the imported module has an attribute by that name\n\n 2. if not, attempt to import a submodule with that name and then\n check the imported module again for that attribute\n\n 3. if the attribute is not found, "ImportError" is raised.\n\n 4. otherwise, a reference to that value is bound in the local\n namespace, using the name in the "as" clause if it is present,\n otherwise using the attribute name\n\nExamples:\n\n import foo # foo imported and bound locally\n import foo.bar.baz # foo.bar.baz imported, foo bound locally\n import foo.bar.baz as fbb # foo.bar.baz imported and bound as fbb\n from foo.bar import baz # foo.bar.baz imported and bound as baz\n from foo import attr # foo imported and foo.attr bound as attr\n\nIf the list of identifiers is replaced by a star ("\'*\'"), all public\nnames defined in the module are bound in the local namespace for the\nscope where the "import" statement occurs.\n\nThe *public names* defined by a module are determined by checking the\nmodule\'s namespace for a variable named "__all__"; if defined, it must\nbe a sequence of strings which are names defined or imported by that\nmodule. The names given in "__all__" are all considered public and\nare required to exist. If "__all__" is not defined, the set of public\nnames includes all names found in the module\'s namespace which do not\nbegin with an underscore character ("\'_\'"). "__all__" should contain\nthe entire public API. It is intended to avoid accidentally exporting\nitems that are not part of the API (such as library modules which were\nimported and used within the module).\n\nThe "from" form with "*" may only occur in a module scope. The wild\ncard form of import --- "import *" --- is only allowed at the module\nlevel. Attempting to use it in class or function definitions will\nraise a "SyntaxError".\n\nWhen specifying what module to import you do not have to specify the\nabsolute name of the module. When a module or package is contained\nwithin another package it is possible to make a relative import within\nthe same top package without having to mention the package name. By\nusing leading dots in the specified module or package after "from" you\ncan specify how high to traverse up the current package hierarchy\nwithout specifying exact names. One leading dot means the current\npackage where the module making the import exists. Two dots means up\none package level. Three dots is up two levels, etc. So if you execute\n"from . import mod" from a module in the "pkg" package then you will\nend up importing "pkg.mod". If you execute "from ..subpkg2 import mod"\nfrom within "pkg.subpkg1" you will import "pkg.subpkg2.mod". The\nspecification for relative imports is contained within **PEP 328**.\n\n"importlib.import_module()" is provided to support applications that\ndetermine which modules need to be loaded dynamically.\n\n\nFuture statements\n=================\n\nA *future statement* is a directive to the compiler that a particular\nmodule should be compiled using syntax or semantics that will be\navailable in a specified future release of Python. The future\nstatement is intended to ease migration to future versions of Python\nthat introduce incompatible changes to the language. It allows use of\nthe new features on a per-module basis before the release in which the\nfeature becomes standard.\n\n future_statement ::= "from" "__future__" "import" feature ["as" name]\n ("," feature ["as" name])*\n | "from" "__future__" "import" "(" feature ["as" name]\n ("," feature ["as" name])* [","] ")"\n feature ::= identifier\n name ::= identifier\n\nA future statement must appear near the top of the module. The only\nlines that can appear before a future statement are:\n\n* the module docstring (if any),\n\n* comments,\n\n* blank lines, and\n\n* other future statements.\n\nThe features recognized by Python 3.0 are "absolute_import",\n"division", "generators", "unicode_literals", "print_function",\n"nested_scopes" and "with_statement". They are all redundant because\nthey are always enabled, and only kept for backwards compatibility.\n\nA future statement is recognized and treated specially at compile\ntime: Changes to the semantics of core constructs are often\nimplemented by generating different code. It may even be the case\nthat a new feature introduces new incompatible syntax (such as a new\nreserved word), in which case the compiler may need to parse the\nmodule differently. Such decisions cannot be pushed off until\nruntime.\n\nFor any given release, the compiler knows which feature names have\nbeen defined, and raises a compile-time error if a future statement\ncontains a feature not known to it.\n\nThe direct runtime semantics are the same as for any import statement:\nthere is a standard module "__future__", described later, and it will\nbe imported in the usual way at the time the future statement is\nexecuted.\n\nThe interesting runtime semantics depend on the specific feature\nenabled by the future statement.\n\nNote that there is nothing special about the statement:\n\n import __future__ [as name]\n\nThat is not a future statement; it\'s an ordinary import statement with\nno special semantics or syntax restrictions.\n\nCode compiled by calls to the built-in functions "exec()" and\n"compile()" that occur in a module "M" containing a future statement\nwill, by default, use the new syntax or semantics associated with the\nfuture statement. This can be controlled by optional arguments to\n"compile()" --- see the documentation of that function for details.\n\nA future statement typed at an interactive interpreter prompt will\ntake effect for the rest of the interpreter session. If an\ninterpreter is started with the *-i* option, is passed a script name\nto execute, and the script includes a future statement, it will be in\neffect in the interactive session started after the script is\nexecuted.\n\nSee also:\n\n **PEP 236** - Back to the __future__\n The original proposal for the __future__ mechanism.\n', - 'in': '\nComparisons\n***********\n\nUnlike C, all comparison operations in Python have the same priority,\nwhich is lower than that of any arithmetic, shifting or bitwise\noperation. Also unlike C, expressions like "a < b < c" have the\ninterpretation that is conventional in mathematics:\n\n comparison ::= or_expr ( comp_operator or_expr )*\n comp_operator ::= "<" | ">" | "==" | ">=" | "<=" | "!="\n | "is" ["not"] | ["not"] "in"\n\nComparisons yield boolean values: "True" or "False".\n\nComparisons can be chained arbitrarily, e.g., "x < y <= z" is\nequivalent to "x < y and y <= z", except that "y" is evaluated only\nonce (but in both cases "z" is not evaluated at all when "x < y" is\nfound to be false).\n\nFormally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *op1*,\n*op2*, ..., *opN* are comparison operators, then "a op1 b op2 c ... y\nopN z" is equivalent to "a op1 b and b op2 c and ... y opN z", except\nthat each expression is evaluated at most once.\n\nNote that "a op1 b op2 c" doesn\'t imply any kind of comparison between\n*a* and *c*, so that, e.g., "x < y > z" is perfectly legal (though\nperhaps not pretty).\n\nThe operators "<", ">", "==", ">=", "<=", and "!=" compare the values\nof two objects. The objects need not have the same type. If both are\nnumbers, they are converted to a common type. Otherwise, the "==" and\n"!=" operators *always* consider objects of different types to be\nunequal, while the "<", ">", ">=" and "<=" operators raise a\n"TypeError" when comparing objects of different types that do not\nimplement these operators for the given pair of types. You can\ncontrol comparison behavior of objects of non-built-in types by\ndefining rich comparison methods like "__gt__()", described in section\n*Basic customization*.\n\nComparison of objects of the same type depends on the type:\n\n* Numbers are compared arithmetically.\n\n* The values "float(\'NaN\')" and "Decimal(\'NaN\')" are special. The are\n identical to themselves, "x is x" but are not equal to themselves,\n "x != x". Additionally, comparing any value to a not-a-number value\n will return "False". For example, both "3 < float(\'NaN\')" and\n "float(\'NaN\') < 3" will return "False".\n\n* Bytes objects are compared lexicographically using the numeric\n values of their elements.\n\n* Strings are compared lexicographically using the numeric equivalents\n (the result of the built-in function "ord()") of their characters.\n [3] String and bytes object can\'t be compared!\n\n* Tuples and lists are compared lexicographically using comparison of\n corresponding elements. This means that to compare equal, each\n element must compare equal and the two sequences must be of the same\n type and have the same length.\n\n If not equal, the sequences are ordered the same as their first\n differing elements. For example, "[1,2,x] <= [1,2,y]" has the same\n value as "x <= y". If the corresponding element does not exist, the\n shorter sequence is ordered first (for example, "[1,2] < [1,2,3]").\n\n* Mappings (dictionaries) compare equal if and only if they have the\n same "(key, value)" pairs. Order comparisons "(\'<\', \'<=\', \'>=\',\n \'>\')" raise "TypeError".\n\n* Sets and frozensets define comparison operators to mean subset and\n superset tests. Those relations do not define total orderings (the\n two sets "{1,2}" and {2,3} are not equal, nor subsets of one\n another, nor supersets of one another). Accordingly, sets are not\n appropriate arguments for functions which depend on total ordering.\n For example, "min()", "max()", and "sorted()" produce undefined\n results given a list of sets as inputs.\n\n* Most other objects of built-in types compare unequal unless they are\n the same object; the choice whether one object is considered smaller\n or larger than another one is made arbitrarily but consistently\n within one execution of a program.\n\nComparison of objects of the differing types depends on whether either\nof the types provide explicit support for the comparison. Most\nnumeric types can be compared with one another. When cross-type\ncomparison is not supported, the comparison method returns\n"NotImplemented".\n\nThe operators "in" and "not in" test for membership. "x in s"\nevaluates to true if *x* is a member of *s*, and false otherwise. "x\nnot in s" returns the negation of "x in s". All built-in sequences\nand set types support this as well as dictionary, for which "in" tests\nwhether a the dictionary has a given key. For container types such as\nlist, tuple, set, frozenset, dict, or collections.deque, the\nexpression "x in y" is equivalent to "any(x is e or x == e for e in\ny)".\n\nFor the string and bytes types, "x in y" is true if and only if *x* is\na substring of *y*. An equivalent test is "y.find(x) != -1". Empty\nstrings are always considered to be a substring of any other string,\nso """ in "abc"" will return "True".\n\nFor user-defined classes which define the "__contains__()" method, "x\nin y" is true if and only if "y.__contains__(x)" is true.\n\nFor user-defined classes which do not define "__contains__()" but do\ndefine "__iter__()", "x in y" is true if some value "z" with "x == z"\nis produced while iterating over "y". If an exception is raised\nduring the iteration, it is as if "in" raised that exception.\n\nLastly, the old-style iteration protocol is tried: if a class defines\n"__getitem__()", "x in y" is true if and only if there is a non-\nnegative integer index *i* such that "x == y[i]", and all lower\ninteger indices do not raise "IndexError" exception. (If any other\nexception is raised, it is as if "in" raised that exception).\n\nThe operator "not in" is defined to have the inverse true value of\n"in".\n\nThe operators "is" and "is not" test for object identity: "x is y" is\ntrue if and only if *x* and *y* are the same object. "x is not y"\nyields the inverse truth value. [4]\n', + 'import': '\nThe "import" statement\n**********************\n\n import_stmt ::= "import" module ["as" name] ( "," module ["as" name] )*\n | "from" relative_module "import" identifier ["as" name]\n ( "," identifier ["as" name] )*\n | "from" relative_module "import" "(" identifier ["as" name]\n ( "," identifier ["as" name] )* [","] ")"\n | "from" module "import" "*"\n module ::= (identifier ".")* identifier\n relative_module ::= "."* module | "."+\n name ::= identifier\n\nThe basic import statement (no "from" clause) is executed in two\nsteps:\n\n1. find a module, loading and initializing it if necessary\n\n2. define a name or names in the local namespace for the scope\n where the "import" statement occurs.\n\nWhen the statement contains multiple clauses (separated by commas) the\ntwo steps are carried out separately for each clause, just as though\nthe clauses had been separated out into individiual import statements.\n\nThe details of the first step, finding and loading modules is\ndescribed in greater detail in the section on the *import system*,\nwhich also describes the various types of packages and modules that\ncan be imported, as well as all the hooks that can be used to\ncustomize the import system. Note that failures in this step may\nindicate either that the module could not be located, *or* that an\nerror occurred while initializing the module, which includes execution\nof the module\'s code.\n\nIf the requested module is retrieved successfully, it will be made\navailable in the local namespace in one of three ways:\n\n* If the module name is followed by "as", then the name following\n "as" is bound directly to the imported module.\n\n* If no other name is specified, and the module being imported is a\n top level module, the module\'s name is bound in the local namespace\n as a reference to the imported module\n\n* If the module being imported is *not* a top level module, then the\n name of the top level package that contains the module is bound in\n the local namespace as a reference to the top level package. The\n imported module must be accessed using its full qualified name\n rather than directly\n\nThe "from" form uses a slightly more complex process:\n\n1. find the module specified in the "from" clause loading and\n initializing it if necessary;\n\n2. for each of the identifiers specified in the "import" clauses:\n\n 1. check if the imported module has an attribute by that name\n\n 2. if not, attempt to import a submodule with that name and then\n check the imported module again for that attribute\n\n 3. if the attribute is not found, "ImportError" is raised.\n\n 4. otherwise, a reference to that value is bound in the local\n namespace, using the name in the "as" clause if it is present,\n otherwise using the attribute name\n\nExamples:\n\n import foo # foo imported and bound locally\n import foo.bar.baz # foo.bar.baz imported, foo bound locally\n import foo.bar.baz as fbb # foo.bar.baz imported and bound as fbb\n from foo.bar import baz # foo.bar.baz imported and bound as baz\n from foo import attr # foo imported and foo.attr bound as attr\n\nIf the list of identifiers is replaced by a star ("\'*\'"), all public\nnames defined in the module are bound in the local namespace for the\nscope where the "import" statement occurs.\n\nThe *public names* defined by a module are determined by checking the\nmodule\'s namespace for a variable named "__all__"; if defined, it must\nbe a sequence of strings which are names defined or imported by that\nmodule. The names given in "__all__" are all considered public and\nare required to exist. If "__all__" is not defined, the set of public\nnames includes all names found in the module\'s namespace which do not\nbegin with an underscore character ("\'_\'"). "__all__" should contain\nthe entire public API. It is intended to avoid accidentally exporting\nitems that are not part of the API (such as library modules which were\nimported and used within the module).\n\nThe "from" form with "*" may only occur in a module scope. The wild\ncard form of import --- "import *" --- is only allowed at the module\nlevel. Attempting to use it in class or function definitions will\nraise a "SyntaxError".\n\nWhen specifying what module to import you do not have to specify the\nabsolute name of the module. When a module or package is contained\nwithin another package it is possible to make a relative import within\nthe same top package without having to mention the package name. By\nusing leading dots in the specified module or package after "from" you\ncan specify how high to traverse up the current package hierarchy\nwithout specifying exact names. One leading dot means the current\npackage where the module making the import exists. Two dots means up\none package level. Three dots is up two levels, etc. So if you execute\n"from . import mod" from a module in the "pkg" package then you will\nend up importing "pkg.mod". If you execute "from ..subpkg2 import mod"\nfrom within "pkg.subpkg1" you will import "pkg.subpkg2.mod". The\nspecification for relative imports is contained within **PEP 328**.\n\n"importlib.import_module()" is provided to support applications that\ndetermine which modules need to be loaded dynamically.\n\n\nFuture statements\n=================\n\nA *future statement* is a directive to the compiler that a particular\nmodule should be compiled using syntax or semantics that will be\navailable in a specified future release of Python. The future\nstatement is intended to ease migration to future versions of Python\nthat introduce incompatible changes to the language. It allows use of\nthe new features on a per-module basis before the release in which the\nfeature becomes standard.\n\n future_statement ::= "from" "__future__" "import" feature ["as" name]\n ("," feature ["as" name])*\n | "from" "__future__" "import" "(" feature ["as" name]\n ("," feature ["as" name])* [","] ")"\n feature ::= identifier\n name ::= identifier\n\nA future statement must appear near the top of the module. The only\nlines that can appear before a future statement are:\n\n* the module docstring (if any),\n\n* comments,\n\n* blank lines, and\n\n* other future statements.\n\nThe features recognized by Python 3.0 are "absolute_import",\n"division", "generators", "unicode_literals", "print_function",\n"nested_scopes" and "with_statement". They are all redundant because\nthey are always enabled, and only kept for backwards compatibility.\n\nA future statement is recognized and treated specially at compile\ntime: Changes to the semantics of core constructs are often\nimplemented by generating different code. It may even be the case\nthat a new feature introduces new incompatible syntax (such as a new\nreserved word), in which case the compiler may need to parse the\nmodule differently. Such decisions cannot be pushed off until\nruntime.\n\nFor any given release, the compiler knows which feature names have\nbeen defined, and raises a compile-time error if a future statement\ncontains a feature not known to it.\n\nThe direct runtime semantics are the same as for any import statement:\nthere is a standard module "__future__", described later, and it will\nbe imported in the usual way at the time the future statement is\nexecuted.\n\nThe interesting runtime semantics depend on the specific feature\nenabled by the future statement.\n\nNote that there is nothing special about the statement:\n\n import __future__ [as name]\n\nThat is not a future statement; it\'s an ordinary import statement with\nno special semantics or syntax restrictions.\n\nCode compiled by calls to the built-in functions "exec()" and\n"compile()" that occur in a module "M" containing a future statement\nwill, by default, use the new syntax or semantics associated with the\nfuture statement. This can be controlled by optional arguments to\n"compile()" --- see the documentation of that function for details.\n\nA future statement typed at an interactive interpreter prompt will\ntake effect for the rest of the interpreter session. If an\ninterpreter is started with the *-i* option, is passed a script name\nto execute, and the script includes a future statement, it will be in\neffect in the interactive session started after the script is\nexecuted.\n\nSee also: **PEP 236** - Back to the __future__\n\n The original proposal for the __future__ mechanism.\n', + 'in': '\nComparisons\n***********\n\nUnlike C, all comparison operations in Python have the same priority,\nwhich is lower than that of any arithmetic, shifting or bitwise\noperation. Also unlike C, expressions like "a < b < c" have the\ninterpretation that is conventional in mathematics:\n\n comparison ::= or_expr ( comp_operator or_expr )*\n comp_operator ::= "<" | ">" | "==" | ">=" | "<=" | "!="\n | "is" ["not"] | ["not"] "in"\n\nComparisons yield boolean values: "True" or "False".\n\nComparisons can be chained arbitrarily, e.g., "x < y <= z" is\nequivalent to "x < y and y <= z", except that "y" is evaluated only\nonce (but in both cases "z" is not evaluated at all when "x < y" is\nfound to be false).\n\nFormally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *op1*,\n*op2*, ..., *opN* are comparison operators, then "a op1 b op2 c ... y\nopN z" is equivalent to "a op1 b and b op2 c and ... y opN z", except\nthat each expression is evaluated at most once.\n\nNote that "a op1 b op2 c" doesn\'t imply any kind of comparison between\n*a* and *c*, so that, e.g., "x < y > z" is perfectly legal (though\nperhaps not pretty).\n\nThe operators "<", ">", "==", ">=", "<=", and "!=" compare the values\nof two objects. The objects need not have the same type. If both are\nnumbers, they are converted to a common type. Otherwise, the "==" and\n"!=" operators *always* consider objects of different types to be\nunequal, while the "<", ">", ">=" and "<=" operators raise a\n"TypeError" when comparing objects of different types that do not\nimplement these operators for the given pair of types. You can\ncontrol comparison behavior of objects of non-built-in types by\ndefining rich comparison methods like "__gt__()", described in section\n*Basic customization*.\n\nComparison of objects of the same type depends on the type:\n\n* Numbers are compared arithmetically.\n\n* The values "float(\'NaN\')" and "Decimal(\'NaN\')" are special. The\n are identical to themselves, "x is x" but are not equal to\n themselves, "x != x". Additionally, comparing any value to a\n not-a-number value will return "False". For example, both "3 <\n float(\'NaN\')" and "float(\'NaN\') < 3" will return "False".\n\n* Bytes objects are compared lexicographically using the numeric\n values of their elements.\n\n* Strings are compared lexicographically using the numeric\n equivalents (the result of the built-in function "ord()") of their\n characters. [3] String and bytes object can\'t be compared!\n\n* Tuples and lists are compared lexicographically using comparison\n of corresponding elements. This means that to compare equal, each\n element must compare equal and the two sequences must be of the same\n type and have the same length.\n\n If not equal, the sequences are ordered the same as their first\n differing elements. For example, "[1,2,x] <= [1,2,y]" has the same\n value as "x <= y". If the corresponding element does not exist, the\n shorter sequence is ordered first (for example, "[1,2] < [1,2,3]").\n\n* Mappings (dictionaries) compare equal if and only if they have the\n same "(key, value)" pairs. Order comparisons "(\'<\', \'<=\', \'>=\',\n \'>\')" raise "TypeError".\n\n* Sets and frozensets define comparison operators to mean subset and\n superset tests. Those relations do not define total orderings (the\n two sets "{1,2}" and {2,3} are not equal, nor subsets of one\n another, nor supersets of one another). Accordingly, sets are not\n appropriate arguments for functions which depend on total ordering.\n For example, "min()", "max()", and "sorted()" produce undefined\n results given a list of sets as inputs.\n\n* Most other objects of built-in types compare unequal unless they\n are the same object; the choice whether one object is considered\n smaller or larger than another one is made arbitrarily but\n consistently within one execution of a program.\n\nComparison of objects of the differing types depends on whether either\nof the types provide explicit support for the comparison. Most\nnumeric types can be compared with one another. When cross-type\ncomparison is not supported, the comparison method returns\n"NotImplemented".\n\nThe operators "in" and "not in" test for membership. "x in s"\nevaluates to true if *x* is a member of *s*, and false otherwise. "x\nnot in s" returns the negation of "x in s". All built-in sequences\nand set types support this as well as dictionary, for which "in" tests\nwhether a the dictionary has a given key. For container types such as\nlist, tuple, set, frozenset, dict, or collections.deque, the\nexpression "x in y" is equivalent to "any(x is e or x == e for e in\ny)".\n\nFor the string and bytes types, "x in y" is true if and only if *x* is\na substring of *y*. An equivalent test is "y.find(x) != -1". Empty\nstrings are always considered to be a substring of any other string,\nso """ in "abc"" will return "True".\n\nFor user-defined classes which define the "__contains__()" method, "x\nin y" is true if and only if "y.__contains__(x)" is true.\n\nFor user-defined classes which do not define "__contains__()" but do\ndefine "__iter__()", "x in y" is true if some value "z" with "x == z"\nis produced while iterating over "y". If an exception is raised\nduring the iteration, it is as if "in" raised that exception.\n\nLastly, the old-style iteration protocol is tried: if a class defines\n"__getitem__()", "x in y" is true if and only if there is a non-\nnegative integer index *i* such that "x == y[i]", and all lower\ninteger indices do not raise "IndexError" exception. (If any other\nexception is raised, it is as if "in" raised that exception).\n\nThe operator "not in" is defined to have the inverse true value of\n"in".\n\nThe operators "is" and "is not" test for object identity: "x is y" is\ntrue if and only if *x* and *y* are the same object. "x is not y"\nyields the inverse truth value. [4]\n', 'integers': '\nInteger literals\n****************\n\nInteger literals are described by the following lexical definitions:\n\n integer ::= decimalinteger | octinteger | hexinteger | bininteger\n decimalinteger ::= nonzerodigit digit* | "0"+\n nonzerodigit ::= "1"..."9"\n digit ::= "0"..."9"\n octinteger ::= "0" ("o" | "O") octdigit+\n hexinteger ::= "0" ("x" | "X") hexdigit+\n bininteger ::= "0" ("b" | "B") bindigit+\n octdigit ::= "0"..."7"\n hexdigit ::= digit | "a"..."f" | "A"..."F"\n bindigit ::= "0" | "1"\n\nThere is no limit for the length of integer literals apart from what\ncan be stored in available memory.\n\nNote that leading zeros in a non-zero decimal number are not allowed.\nThis is for disambiguation with C-style octal literals, which Python\nused before version 3.0.\n\nSome examples of integer literals:\n\n 7 2147483647 0o177 0b100110111\n 3 79228162514264337593543950336 0o377 0x100000000\n 79228162514264337593543950336 0xdeadbeef\n', 'lambda': '\nLambdas\n*******\n\n lambda_expr ::= "lambda" [parameter_list]: expression\n lambda_expr_nocond ::= "lambda" [parameter_list]: expression_nocond\n\nLambda expressions (sometimes called lambda forms) have the same\nsyntactic position as expressions. They are a shorthand to create\nanonymous functions; the expression "lambda arguments: expression"\nyields a function object. The unnamed object behaves like a function\nobject defined with\n\n def <lambda>(arguments):\n return expression\n\nSee section *Function definitions* for the syntax of parameter lists.\nNote that functions created with lambda expressions cannot contain\nstatements or annotations.\n', 'lists': '\nList displays\n*************\n\nA list display is a possibly empty series of expressions enclosed in\nsquare brackets:\n\n list_display ::= "[" [expression_list | comprehension] "]"\n\nA list display yields a new list object, the contents being specified\nby either a list of expressions or a comprehension. When a comma-\nseparated list of expressions is supplied, its elements are evaluated\nfrom left to right and placed into the list object in that order.\nWhen a comprehension is supplied, the list is constructed from the\nelements resulting from the comprehension.\n', 'naming': '\nNaming and binding\n******************\n\n*Names* refer to objects. Names are introduced by name binding\noperations. Each occurrence of a name in the program text refers to\nthe *binding* of that name established in the innermost function block\ncontaining the use.\n\nA *block* is a piece of Python program text that is executed as a\nunit. The following are blocks: a module, a function body, and a class\ndefinition. Each command typed interactively is a block. A script\nfile (a file given as standard input to the interpreter or specified\non the interpreter command line the first argument) is a code block.\nA script command (a command specified on the interpreter command line\nwith the \'**-c**\' option) is a code block. The string argument passed\nto the built-in functions "eval()" and "exec()" is a code block.\n\nA code block is executed in an *execution frame*. A frame contains\nsome administrative information (used for debugging) and determines\nwhere and how execution continues after the code block\'s execution has\ncompleted.\n\nA *scope* defines the visibility of a name within a block. If a local\nvariable is defined in a block, its scope includes that block. If the\ndefinition occurs in a function block, the scope extends to any blocks\ncontained within the defining one, unless a contained block introduces\na different binding for the name. The scope of names defined in a\nclass block is limited to the class block; it does not extend to the\ncode blocks of methods -- this includes comprehensions and generator\nexpressions since they are implemented using a function scope. This\nmeans that the following will fail:\n\n class A:\n a = 42\n b = list(a + i for i in range(10))\n\nWhen a name is used in a code block, it is resolved using the nearest\nenclosing scope. The set of all such scopes visible to a code block\nis called the block\'s *environment*.\n\nIf a name is bound in a block, it is a local variable of that block,\nunless declared as "nonlocal". If a name is bound at the module\nlevel, it is a global variable. (The variables of the module code\nblock are local and global.) If a variable is used in a code block\nbut not defined there, it is a *free variable*.\n\nWhen a name is not found at all, a "NameError" exception is raised.\nIf the name refers to a local variable that has not been bound, a\n"UnboundLocalError" exception is raised. "UnboundLocalError" is a\nsubclass of "NameError".\n\nThe following constructs bind names: formal parameters to functions,\n"import" statements, class and function definitions (these bind the\nclass or function name in the defining block), and targets that are\nidentifiers if occurring in an assignment, "for" loop header, or after\n"as" in a "with" statement or "except" clause. The "import" statement\nof the form "from ... import *" binds all names defined in the\nimported module, except those beginning with an underscore. This form\nmay only be used at the module level.\n\nA target occurring in a "del" statement is also considered bound for\nthis purpose (though the actual semantics are to unbind the name).\n\nEach assignment or import statement occurs within a block defined by a\nclass or function definition or at the module level (the top-level\ncode block).\n\nIf a name binding operation occurs anywhere within a code block, all\nuses of the name within the block are treated as references to the\ncurrent block. This can lead to errors when a name is used within a\nblock before it is bound. This rule is subtle. Python lacks\ndeclarations and allows name binding operations to occur anywhere\nwithin a code block. The local variables of a code block can be\ndetermined by scanning the entire text of the block for name binding\noperations.\n\nIf the "global" statement occurs within a block, all uses of the name\nspecified in the statement refer to the binding of that name in the\ntop-level namespace. Names are resolved in the top-level namespace by\nsearching the global namespace, i.e. the namespace of the module\ncontaining the code block, and the builtins namespace, the namespace\nof the module "builtins". The global namespace is searched first. If\nthe name is not found there, the builtins namespace is searched. The\nglobal statement must precede all uses of the name.\n\nThe builtins namespace associated with the execution of a code block\nis actually found by looking up the name "__builtins__" in its global\nnamespace; this should be a dictionary or a module (in the latter case\nthe module\'s dictionary is used). By default, when in the "__main__"\nmodule, "__builtins__" is the built-in module "builtins"; when in any\nother module, "__builtins__" is an alias for the dictionary of the\n"builtins" module itself. "__builtins__" can be set to a user-created\ndictionary to create a weak form of restricted execution.\n\n**CPython implementation detail:** Users should not touch\n"__builtins__"; it is strictly an implementation detail. Users\nwanting to override values in the builtins namespace should "import"\nthe "builtins" module and modify its attributes appropriately.\n\nThe namespace for a module is automatically created the first time a\nmodule is imported. The main module for a script is always called\n"__main__".\n\nThe "global" statement has the same scope as a name binding operation\nin the same block. If the nearest enclosing scope for a free variable\ncontains a global statement, the free variable is treated as a global.\n\nA class definition is an executable statement that may use and define\nnames. These references follow the normal rules for name resolution.\nThe namespace of the class definition becomes the attribute dictionary\nof the class. Names defined at the class scope are not visible in\nmethods.\n\n\nInteraction with dynamic features\n=================================\n\nThere are several cases where Python statements are illegal when used\nin conjunction with nested scopes that contain free variables.\n\nIf a variable is referenced in an enclosing scope, it is illegal to\ndelete the name. An error will be reported at compile time.\n\nIf the wild card form of import --- "import *" --- is used in a\nfunction and the function contains or is a nested block with free\nvariables, the compiler will raise a "SyntaxError".\n\nThe "eval()" and "exec()" functions do not have access to the full\nenvironment for resolving names. Names may be resolved in the local\nand global namespaces of the caller. Free variables are not resolved\nin the nearest enclosing namespace, but in the global namespace. [1]\nThe "exec()" and "eval()" functions have optional arguments to\noverride the global and local namespace. If only one namespace is\nspecified, it is used for both.\n', - 'nonlocal': '\nThe "nonlocal" statement\n************************\n\n nonlocal_stmt ::= "nonlocal" identifier ("," identifier)*\n\nThe "nonlocal" statement causes the listed identifiers to refer to\npreviously bound variables in the nearest enclosing scope. This is\nimportant because the default behavior for binding is to search the\nlocal namespace first. The statement allows encapsulated code to\nrebind variables outside of the local scope besides the global\n(module) scope.\n\nNames listed in a "nonlocal" statement, unlike to those listed in a\n"global" statement, must refer to pre-existing bindings in an\nenclosing scope (the scope in which a new binding should be created\ncannot be determined unambiguously).\n\nNames listed in a "nonlocal" statement must not collide with pre-\nexisting bindings in the local scope.\n\nSee also:\n\n **PEP 3104** - Access to Names in Outer Scopes\n The specification for the "nonlocal" statement.\n', + 'nonlocal': '\nThe "nonlocal" statement\n************************\n\n nonlocal_stmt ::= "nonlocal" identifier ("," identifier)*\n\nThe "nonlocal" statement causes the listed identifiers to refer to\npreviously bound variables in the nearest enclosing scope. This is\nimportant because the default behavior for binding is to search the\nlocal namespace first. The statement allows encapsulated code to\nrebind variables outside of the local scope besides the global\n(module) scope.\n\nNames listed in a "nonlocal" statement, unlike to those listed in a\n"global" statement, must refer to pre-existing bindings in an\nenclosing scope (the scope in which a new binding should be created\ncannot be determined unambiguously).\n\nNames listed in a "nonlocal" statement must not collide with pre-\nexisting bindings in the local scope.\n\nSee also: **PEP 3104** - Access to Names in Outer Scopes\n\n The specification for the "nonlocal" statement.\n', 'numbers': '\nNumeric literals\n****************\n\nThere are three types of numeric literals: integers, floating point\nnumbers, and imaginary numbers. There are no complex literals\n(complex numbers can be formed by adding a real number and an\nimaginary number).\n\nNote that numeric literals do not include a sign; a phrase like "-1"\nis actually an expression composed of the unary operator \'"-"\' and the\nliteral "1".\n', - 'numeric-types': '\nEmulating numeric types\n***********************\n\nThe following methods can be defined to emulate numeric objects.\nMethods corresponding to operations that are not supported by the\nparticular kind of number implemented (e.g., bitwise operations for\nnon-integral numbers) should be left undefined.\n\nobject.__add__(self, other)\nobject.__sub__(self, other)\nobject.__mul__(self, other)\nobject.__truediv__(self, other)\nobject.__floordiv__(self, other)\nobject.__mod__(self, other)\nobject.__divmod__(self, other)\nobject.__pow__(self, other[, modulo])\nobject.__lshift__(self, other)\nobject.__rshift__(self, other)\nobject.__and__(self, other)\nobject.__xor__(self, other)\nobject.__or__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|"). For instance, to evaluate the\n expression "x + y", where *x* is an instance of a class that has an\n "__add__()" method, "x.__add__(y)" is called. The "__divmod__()"\n method should be the equivalent to using "__floordiv__()" and\n "__mod__()"; it should not be related to "__truediv__()". Note\n that "__pow__()" should be defined to accept an optional third\n argument if the ternary version of the built-in "pow()" function is\n to be supported.\n\n If one of those methods does not support the operation with the\n supplied arguments, it should return "NotImplemented".\n\nobject.__radd__(self, other)\nobject.__rsub__(self, other)\nobject.__rmul__(self, other)\nobject.__rtruediv__(self, other)\nobject.__rfloordiv__(self, other)\nobject.__rmod__(self, other)\nobject.__rdivmod__(self, other)\nobject.__rpow__(self, other)\nobject.__rlshift__(self, other)\nobject.__rrshift__(self, other)\nobject.__rand__(self, other)\nobject.__rxor__(self, other)\nobject.__ror__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|") with reflected (swapped) operands.\n These functions are only called if the left operand does not\n support the corresponding operation and the operands are of\n different types. [2] For instance, to evaluate the expression "x -\n y", where *y* is an instance of a class that has an "__rsub__()"\n method, "y.__rsub__(x)" is called if "x.__sub__(y)" returns\n *NotImplemented*.\n\n Note that ternary "pow()" will not try calling "__rpow__()" (the\n coercion rules would become too complicated).\n\n Note: If the right operand\'s type is a subclass of the left operand\'s\n type and that subclass provides the reflected method for the\n operation, this method will be called before the left operand\'s\n non-reflected method. This behavior allows subclasses to\n override their ancestors\' operations.\n\nobject.__iadd__(self, other)\nobject.__isub__(self, other)\nobject.__imul__(self, other)\nobject.__itruediv__(self, other)\nobject.__ifloordiv__(self, other)\nobject.__imod__(self, other)\nobject.__ipow__(self, other[, modulo])\nobject.__ilshift__(self, other)\nobject.__irshift__(self, other)\nobject.__iand__(self, other)\nobject.__ixor__(self, other)\nobject.__ior__(self, other)\n\n These methods are called to implement the augmented arithmetic\n assignments ("+=", "-=", "*=", "/=", "//=", "%=", "**=", "<<=",\n ">>=", "&=", "^=", "|="). These methods should attempt to do the\n operation in-place (modifying *self*) and return the result (which\n could be, but does not have to be, *self*). If a specific method\n is not defined, the augmented assignment falls back to the normal\n methods. For instance, if *x* is an instance of a class with an\n "__iadd__()" method, "x += y" is equivalent to "x = x.__iadd__(y)"\n . Otherwise, "x.__add__(y)" and "y.__radd__(x)" are considered, as\n with the evaluation of "x + y". In certain situations, augmented\n assignment can result in unexpected errors (see *Why does\n a_tuple[i] += [\'item\'] raise an exception when the addition\n works?*), but this behavior is in fact part of the data model.\n\nobject.__neg__(self)\nobject.__pos__(self)\nobject.__abs__(self)\nobject.__invert__(self)\n\n Called to implement the unary arithmetic operations ("-", "+",\n "abs()" and "~").\n\nobject.__complex__(self)\nobject.__int__(self)\nobject.__float__(self)\nobject.__round__(self[, n])\n\n Called to implement the built-in functions "complex()", "int()",\n "float()" and "round()". Should return a value of the appropriate\n type.\n\nobject.__index__(self)\n\n Called to implement "operator.index()", and whenever Python needs\n to losslessly convert the numeric object to an integer object (such\n as in slicing, or in the built-in "bin()", "hex()" and "oct()"\n functions). Presence of this method indicates that the numeric\n object is an integer type. Must return an integer.\n\n Note: When "__index__()" is defined, "__int__()" should also be\n defined, and both shuld return the same value, in order to have a\n coherent integer type class.\n', + 'numeric-types': '\nEmulating numeric types\n***********************\n\nThe following methods can be defined to emulate numeric objects.\nMethods corresponding to operations that are not supported by the\nparticular kind of number implemented (e.g., bitwise operations for\nnon-integral numbers) should be left undefined.\n\nobject.__add__(self, other)\nobject.__sub__(self, other)\nobject.__mul__(self, other)\nobject.__truediv__(self, other)\nobject.__floordiv__(self, other)\nobject.__mod__(self, other)\nobject.__divmod__(self, other)\nobject.__pow__(self, other[, modulo])\nobject.__lshift__(self, other)\nobject.__rshift__(self, other)\nobject.__and__(self, other)\nobject.__xor__(self, other)\nobject.__or__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|"). For instance, to evaluate the\n expression "x + y", where *x* is an instance of a class that has an\n "__add__()" method, "x.__add__(y)" is called. The "__divmod__()"\n method should be the equivalent to using "__floordiv__()" and\n "__mod__()"; it should not be related to "__truediv__()". Note\n that "__pow__()" should be defined to accept an optional third\n argument if the ternary version of the built-in "pow()" function is\n to be supported.\n\n If one of those methods does not support the operation with the\n supplied arguments, it should return "NotImplemented".\n\nobject.__radd__(self, other)\nobject.__rsub__(self, other)\nobject.__rmul__(self, other)\nobject.__rtruediv__(self, other)\nobject.__rfloordiv__(self, other)\nobject.__rmod__(self, other)\nobject.__rdivmod__(self, other)\nobject.__rpow__(self, other)\nobject.__rlshift__(self, other)\nobject.__rrshift__(self, other)\nobject.__rand__(self, other)\nobject.__rxor__(self, other)\nobject.__ror__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|") with reflected (swapped) operands.\n These functions are only called if the left operand does not\n support the corresponding operation and the operands are of\n different types. [2] For instance, to evaluate the expression "x -\n y", where *y* is an instance of a class that has an "__rsub__()"\n method, "y.__rsub__(x)" is called if "x.__sub__(y)" returns\n *NotImplemented*.\n\n Note that ternary "pow()" will not try calling "__rpow__()" (the\n coercion rules would become too complicated).\n\n Note: If the right operand\'s type is a subclass of the left\n operand\'s type and that subclass provides the reflected method\n for the operation, this method will be called before the left\n operand\'s non-reflected method. This behavior allows subclasses\n to override their ancestors\' operations.\n\nobject.__iadd__(self, other)\nobject.__isub__(self, other)\nobject.__imul__(self, other)\nobject.__itruediv__(self, other)\nobject.__ifloordiv__(self, other)\nobject.__imod__(self, other)\nobject.__ipow__(self, other[, modulo])\nobject.__ilshift__(self, other)\nobject.__irshift__(self, other)\nobject.__iand__(self, other)\nobject.__ixor__(self, other)\nobject.__ior__(self, other)\n\n These methods are called to implement the augmented arithmetic\n assignments ("+=", "-=", "*=", "/=", "//=", "%=", "**=", "<<=",\n ">>=", "&=", "^=", "|="). These methods should attempt to do the\n operation in-place (modifying *self*) and return the result (which\n could be, but does not have to be, *self*). If a specific method\n is not defined, the augmented assignment falls back to the normal\n methods. For instance, to execute the statement "x += y", where\n *x* is an instance of a class that has an "__iadd__()" method,\n "x.__iadd__(y)" is called. If *x* is an instance of a class that\n does not define a "__iadd__()" method, "x.__add__(y)" and\n "y.__radd__(x)" are considered, as with the evaluation of "x + y".\n\nobject.__neg__(self)\nobject.__pos__(self)\nobject.__abs__(self)\nobject.__invert__(self)\n\n Called to implement the unary arithmetic operations ("-", "+",\n "abs()" and "~").\n\nobject.__complex__(self)\nobject.__int__(self)\nobject.__float__(self)\nobject.__round__(self[, n])\n\n Called to implement the built-in functions "complex()", "int()",\n "float()" and "round()". Should return a value of the appropriate\n type.\n\nobject.__index__(self)\n\n Called to implement "operator.index()", and whenever Python needs\n to losslessly convert the numeric object to an integer object (such\n as in slicing, or in the built-in "bin()", "hex()" and "oct()"\n functions). Presence of this method indicates that the numeric\n object is an integer type. Must return an integer.\n\n Note: When "__index__()" is defined, "__int__()" should also be\n defined, and both shuld return the same value, in order to have a\n coherent integer type class.\n', 'objects': '\nObjects, values and types\n*************************\n\n*Objects* are Python\'s abstraction for data. All data in a Python\nprogram is represented by objects or by relations between objects. (In\na sense, and in conformance to Von Neumann\'s model of a "stored\nprogram computer," code is also represented by objects.)\n\nEvery object has an identity, a type and a value. An object\'s\n*identity* never changes once it has been created; you may think of it\nas the object\'s address in memory. The \'"is"\' operator compares the\nidentity of two objects; the "id()" function returns an integer\nrepresenting its identity.\n\n**CPython implementation detail:** For CPython, "id(x)" is the memory\naddress where "x" is stored.\n\nAn object\'s type determines the operations that the object supports\n(e.g., "does it have a length?") and also defines the possible values\nfor objects of that type. The "type()" function returns an object\'s\ntype (which is an object itself). Like its identity, an object\'s\n*type* is also unchangeable. [1]\n\nThe *value* of some objects can change. Objects whose value can\nchange are said to be *mutable*; objects whose value is unchangeable\nonce they are created are called *immutable*. (The value of an\nimmutable container object that contains a reference to a mutable\nobject can change when the latter\'s value is changed; however the\ncontainer is still considered immutable, because the collection of\nobjects it contains cannot be changed. So, immutability is not\nstrictly the same as having an unchangeable value, it is more subtle.)\nAn object\'s mutability is determined by its type; for instance,\nnumbers, strings and tuples are immutable, while dictionaries and\nlists are mutable.\n\nObjects are never explicitly destroyed; however, when they become\nunreachable they may be garbage-collected. An implementation is\nallowed to postpone garbage collection or omit it altogether --- it is\na matter of implementation quality how garbage collection is\nimplemented, as long as no objects are collected that are still\nreachable.\n\n**CPython implementation detail:** CPython currently uses a reference-\ncounting scheme with (optional) delayed detection of cyclically linked\ngarbage, which collects most objects as soon as they become\nunreachable, but is not guaranteed to collect garbage containing\ncircular references. See the documentation of the "gc" module for\ninformation on controlling the collection of cyclic garbage. Other\nimplementations act differently and CPython may change. Do not depend\non immediate finalization of objects when they become unreachable (ex:\nalways close files).\n\nNote that the use of the implementation\'s tracing or debugging\nfacilities may keep objects alive that would normally be collectable.\nAlso note that catching an exception with a \'"try"..."except"\'\nstatement may keep objects alive.\n\nSome objects contain references to "external" resources such as open\nfiles or windows. It is understood that these resources are freed\nwhen the object is garbage-collected, but since garbage collection is\nnot guaranteed to happen, such objects also provide an explicit way to\nrelease the external resource, usually a "close()" method. Programs\nare strongly recommended to explicitly close such objects. The\n\'"try"..."finally"\' statement and the \'"with"\' statement provide\nconvenient ways to do this.\n\nSome objects contain references to other objects; these are called\n*containers*. Examples of containers are tuples, lists and\ndictionaries. The references are part of a container\'s value. In\nmost cases, when we talk about the value of a container, we imply the\nvalues, not the identities of the contained objects; however, when we\ntalk about the mutability of a container, only the identities of the\nimmediately contained objects are implied. So, if an immutable\ncontainer (like a tuple) contains a reference to a mutable object, its\nvalue changes if that mutable object is changed.\n\nTypes affect almost all aspects of object behavior. Even the\nimportance of object identity is affected in some sense: for immutable\ntypes, operations that compute new values may actually return a\nreference to any existing object with the same type and value, while\nfor mutable objects this is not allowed. E.g., after "a = 1; b = 1",\n"a" and "b" may or may not refer to the same object with the value\none, depending on the implementation, but after "c = []; d = []", "c"\nand "d" are guaranteed to refer to two different, unique, newly\ncreated empty lists. (Note that "c = d = []" assigns the same object\nto both "c" and "d".)\n', - 'operator-summary': '\nOperator precedence\n*******************\n\nThe following table summarizes the operator precedences in Python,\nfrom lowest precedence (least binding) to highest precedence (most\nbinding). Operators in the same box have the same precedence. Unless\nthe syntax is explicitly given, operators are binary. Operators in\nthe same box group left to right (except for comparisons, including\ntests, which all have the same precedence and chain from left to right\n--- see section *Comparisons* --- and exponentiation, which groups\nfrom right to left).\n\n+-------------------------------------------------+---------------------------------------+\n| Operator | Description |\n+=================================================+=======================================+\n| "lambda" | Lambda expression |\n+-------------------------------------------------+---------------------------------------+\n| "if" -- "else" | Conditional expression |\n+-------------------------------------------------+---------------------------------------+\n| "or" | Boolean OR |\n+-------------------------------------------------+---------------------------------------+\n| "and" | Boolean AND |\n+-------------------------------------------------+---------------------------------------+\n| "not" "x" | Boolean NOT |\n+-------------------------------------------------+---------------------------------------+\n| "in", "not in", "is", "is not", "<", "<=", ">", | Comparisons, including membership |\n| ">=", "!=", "==" | tests and identity tests |\n+-------------------------------------------------+---------------------------------------+\n| "|" | Bitwise OR |\n+-------------------------------------------------+---------------------------------------+\n| "^" | Bitwise XOR |\n+-------------------------------------------------+---------------------------------------+\n| "&" | Bitwise AND |\n+-------------------------------------------------+---------------------------------------+\n| "<<", ">>" | Shifts |\n+-------------------------------------------------+---------------------------------------+\n| "+", "-" | Addition and subtraction |\n+-------------------------------------------------+---------------------------------------+\n| "*", "/", "//", "%" | Multiplication, division, remainder |\n+-------------------------------------------------+---------------------------------------+\n| "+x", "-x", "~x" | Positive, negative, bitwise NOT |\n+-------------------------------------------------+---------------------------------------+\n| "**" | Exponentiation [6] |\n+-------------------------------------------------+---------------------------------------+\n| "x[index]", "x[index:index]", | Subscription, slicing, call, |\n| "x(arguments...)", "x.attribute" | attribute reference |\n+-------------------------------------------------+---------------------------------------+\n| "(expressions...)", "[expressions...]", "{key: | Binding or tuple display, list |\n| value...}", "{expressions...}" | display, dictionary display, set |\n+-------------------------------------------------+---------------------------------------+\n\n-[ Footnotes ]-\n\n[1] While "abs(x%y) < abs(y)" is true mathematically, for floats it\n may not be true numerically due to roundoff. For example, and\n assuming a platform on which a Python float is an IEEE 754 double-\n precision number, in order that "-1e-100 % 1e100" have the same\n sign as "1e100", the computed result is "-1e-100 + 1e100", which\n is numerically exactly equal to "1e100". The function\n "math.fmod()" returns a result whose sign matches the sign of the\n first argument instead, and so returns "-1e-100" in this case.\n Which approach is more appropriate depends on the application.\n\n[2] If x is very close to an exact integer multiple of y, it\'s\n possible for "x//y" to be one larger than "(x-x%y)//y" due to\n rounding. In such cases, Python returns the latter result, in\n order to preserve that "divmod(x,y)[0] * y + x % y" be very close\n to "x".\n\n[3] While comparisons between strings make sense at the byte level,\n they may be counter-intuitive to users. For example, the strings\n ""\\u00C7"" and ""\\u0327\\u0043"" compare differently, even though\n they both represent the same unicode character (LATIN CAPITAL\n LETTER C WITH CEDILLA). To compare strings in a human\n recognizable way, compare using "unicodedata.normalize()".\n\n[4] Due to automatic garbage-collection, free lists, and the dynamic\n nature of descriptors, you may notice seemingly unusual behaviour\n in certain uses of the "is" operator, like those involving\n comparisons between instance methods, or constants. Check their\n documentation for more info.\n\n[5] The "%" operator is also used for string formatting; the same\n precedence applies.\n\n[6] The power operator "**" binds less tightly than an arithmetic or\n bitwise unary operator on its right, that is, "2**-1" is "0.5".\n', + 'operator-summary': '\nOperator precedence\n*******************\n\nThe following table summarizes the operator precedences in Python,\nfrom lowest precedence (least binding) to highest precedence (most\nbinding). Operators in the same box have the same precedence. Unless\nthe syntax is explicitly given, operators are binary. Operators in\nthe same box group left to right (except for comparisons, including\ntests, which all have the same precedence and chain from left to right\n--- see section *Comparisons* --- and exponentiation, which groups\nfrom right to left).\n\n+-------------------------------------------------+---------------------------------------+\n| Operator | Description |\n+=================================================+=======================================+\n| "lambda" | Lambda expression |\n+-------------------------------------------------+---------------------------------------+\n| "if" -- "else" | Conditional expression |\n+-------------------------------------------------+---------------------------------------+\n| "or" | Boolean OR |\n+-------------------------------------------------+---------------------------------------+\n| "and" | Boolean AND |\n+-------------------------------------------------+---------------------------------------+\n| "not" "x" | Boolean NOT |\n+-------------------------------------------------+---------------------------------------+\n| "in", "not in", "is", "is not", "<", "<=", ">", | Comparisons, including membership |\n| ">=", "!=", "==" | tests and identity tests |\n+-------------------------------------------------+---------------------------------------+\n| "|" | Bitwise OR |\n+-------------------------------------------------+---------------------------------------+\n| "^" | Bitwise XOR |\n+-------------------------------------------------+---------------------------------------+\n| "&" | Bitwise AND |\n+-------------------------------------------------+---------------------------------------+\n| "<<", ">>" | Shifts |\n+-------------------------------------------------+---------------------------------------+\n| "+", "-" | Addition and subtraction |\n+-------------------------------------------------+---------------------------------------+\n| "*", "/", "//", "%" | Multiplication, division, remainder |\n+-------------------------------------------------+---------------------------------------+\n| "+x", "-x", "~x" | Positive, negative, bitwise NOT |\n+-------------------------------------------------+---------------------------------------+\n| "**" | Exponentiation [6] |\n+-------------------------------------------------+---------------------------------------+\n| "x[index]", "x[index:index]", | Subscription, slicing, call, |\n| "x(arguments...)", "x.attribute" | attribute reference |\n+-------------------------------------------------+---------------------------------------+\n| "(expressions...)", "[expressions...]", "{key: | Binding or tuple display, list |\n| value...}", "{expressions...}" | display, dictionary display, set |\n+-------------------------------------------------+---------------------------------------+\n\n-[ Footnotes ]-\n\n[1] While "abs(x%y) < abs(y)" is true mathematically, for floats\n it may not be true numerically due to roundoff. For example, and\n assuming a platform on which a Python float is an IEEE 754 double-\n precision number, in order that "-1e-100 % 1e100" have the same\n sign as "1e100", the computed result is "-1e-100 + 1e100", which\n is numerically exactly equal to "1e100". The function\n "math.fmod()" returns a result whose sign matches the sign of the\n first argument instead, and so returns "-1e-100" in this case.\n Which approach is more appropriate depends on the application.\n\n[2] If x is very close to an exact integer multiple of y, it\'s\n possible for "x//y" to be one larger than "(x-x%y)//y" due to\n rounding. In such cases, Python returns the latter result, in\n order to preserve that "divmod(x,y)[0] * y + x % y" be very close\n to "x".\n\n[3] While comparisons between strings make sense at the byte\n level, they may be counter-intuitive to users. For example, the\n strings ""\\u00C7"" and ""\\u0327\\u0043"" compare differently, even\n though they both represent the same unicode character (LATIN\n CAPITAL LETTER C WITH CEDILLA). To compare strings in a human\n recognizable way, compare using "unicodedata.normalize()".\n\n[4] Due to automatic garbage-collection, free lists, and the\n dynamic nature of descriptors, you may notice seemingly unusual\n behaviour in certain uses of the "is" operator, like those\n involving comparisons between instance methods, or constants.\n Check their documentation for more info.\n\n[5] The "%" operator is also used for string formatting; the same\n precedence applies.\n\n[6] The power operator "**" binds less tightly than an arithmetic\n or bitwise unary operator on its right, that is, "2**-1" is "0.5".\n', 'pass': '\nThe "pass" statement\n********************\n\n pass_stmt ::= "pass"\n\n"pass" is a null operation --- when it is executed, nothing happens.\nIt is useful as a placeholder when a statement is required\nsyntactically, but no code needs to be executed, for example:\n\n def f(arg): pass # a function that does nothing (yet)\n\n class C: pass # a class with no methods (yet)\n', 'power': '\nThe power operator\n******************\n\nThe power operator binds more tightly than unary operators on its\nleft; it binds less tightly than unary operators on its right. The\nsyntax is:\n\n power ::= primary ["**" u_expr]\n\nThus, in an unparenthesized sequence of power and unary operators, the\noperators are evaluated from right to left (this does not constrain\nthe evaluation order for the operands): "-1**2" results in "-1".\n\nThe power operator has the same semantics as the built-in "pow()"\nfunction, when called with two arguments: it yields its left argument\nraised to the power of its right argument. The numeric arguments are\nfirst converted to a common type, and the result is of that type.\n\nFor int operands, the result has the same type as the operands unless\nthe second argument is negative; in that case, all arguments are\nconverted to float and a float result is delivered. For example,\n"10**2" returns "100", but "10**-2" returns "0.01".\n\nRaising "0.0" to a negative power results in a "ZeroDivisionError".\nRaising a negative number to a fractional power results in a "complex"\nnumber. (In earlier versions it raised a "ValueError".)\n', 'raise': '\nThe "raise" statement\n*********************\n\n raise_stmt ::= "raise" [expression ["from" expression]]\n\nIf no expressions are present, "raise" re-raises the last exception\nthat was active in the current scope. If no exception is active in\nthe current scope, a "RuntimeError" exception is raised indicating\nthat this is an error.\n\nOtherwise, "raise" evaluates the first expression as the exception\nobject. It must be either a subclass or an instance of\n"BaseException". If it is a class, the exception instance will be\nobtained when needed by instantiating the class with no arguments.\n\nThe *type* of the exception is the exception instance\'s class, the\n*value* is the instance itself.\n\nA traceback object is normally created automatically when an exception\nis raised and attached to it as the "__traceback__" attribute, which\nis writable. You can create an exception and set your own traceback in\none step using the "with_traceback()" exception method (which returns\nthe same exception instance, with its traceback set to its argument),\nlike so:\n\n raise Exception("foo occurred").with_traceback(tracebackobj)\n\nThe "from" clause is used for exception chaining: if given, the second\n*expression* must be another exception class or instance, which will\nthen be attached to the raised exception as the "__cause__" attribute\n(which is writable). If the raised exception is not handled, both\nexceptions will be printed:\n\n >>> try:\n ... print(1 / 0)\n ... except Exception as exc:\n ... raise RuntimeError("Something bad happened") from exc\n ...\n Traceback (most recent call last):\n File "<stdin>", line 2, in <module>\n ZeroDivisionError: int division or modulo by zero\n\n The above exception was the direct cause of the following exception:\n\n Traceback (most recent call last):\n File "<stdin>", line 4, in <module>\n RuntimeError: Something bad happened\n\nA similar mechanism works implicitly if an exception is raised inside\nan exception handler: the previous exception is then attached as the\nnew exception\'s "__context__" attribute:\n\n >>> try:\n ... print(1 / 0)\n ... except:\n ... raise RuntimeError("Something bad happened")\n ...\n Traceback (most recent call last):\n File "<stdin>", line 2, in <module>\n ZeroDivisionError: int division or modulo by zero\n\n During handling of the above exception, another exception occurred:\n\n Traceback (most recent call last):\n File "<stdin>", line 4, in <module>\n RuntimeError: Something bad happened\n\nAdditional information on exceptions can be found in section\n*Exceptions*, and information about handling exceptions is in section\n*The try statement*.\n', 'return': '\nThe "return" statement\n**********************\n\n return_stmt ::= "return" [expression_list]\n\n"return" may only occur syntactically nested in a function definition,\nnot within a nested class definition.\n\nIf an expression list is present, it is evaluated, else "None" is\nsubstituted.\n\n"return" leaves the current function call with the expression list (or\n"None") as return value.\n\nWhen "return" passes control out of a "try" statement with a "finally"\nclause, that "finally" clause is executed before really leaving the\nfunction.\n\nIn a generator function, the "return" statement indicates that the\ngenerator is done and will cause "StopIteration" to be raised. The\nreturned value (if any) is used as an argument to construct\n"StopIteration" and becomes the "StopIteration.value" attribute.\n', - 'sequence-types': '\nEmulating container types\n*************************\n\nThe following methods can be defined to implement container objects.\nContainers usually are sequences (such as lists or tuples) or mappings\n(like dictionaries), but can represent other containers as well. The\nfirst set of methods is used either to emulate a sequence or to\nemulate a mapping; the difference is that for a sequence, the\nallowable keys should be the integers *k* for which "0 <= k < N" where\n*N* is the length of the sequence, or slice objects, which define a\nrange of items. It is also recommended that mappings provide the\nmethods "keys()", "values()", "items()", "get()", "clear()",\n"setdefault()", "pop()", "popitem()", "copy()", and "update()"\nbehaving similar to those for Python\'s standard dictionary objects.\nThe "collections" module provides a "MutableMapping" abstract base\nclass to help create those methods from a base set of "__getitem__()",\n"__setitem__()", "__delitem__()", and "keys()". Mutable sequences\nshould provide methods "append()", "count()", "index()", "extend()",\n"insert()", "pop()", "remove()", "reverse()" and "sort()", like Python\nstandard list objects. Finally, sequence types should implement\naddition (meaning concatenation) and multiplication (meaning\nrepetition) by defining the methods "__add__()", "__radd__()",\n"__iadd__()", "__mul__()", "__rmul__()" and "__imul__()" described\nbelow; they should not define other numerical operators. It is\nrecommended that both mappings and sequences implement the\n"__contains__()" method to allow efficient use of the "in" operator;\nfor mappings, "in" should search the mapping\'s keys; for sequences, it\nshould search through the values. It is further recommended that both\nmappings and sequences implement the "__iter__()" method to allow\nefficient iteration through the container; for mappings, "__iter__()"\nshould be the same as "keys()"; for sequences, it should iterate\nthrough the values.\n\nobject.__len__(self)\n\n Called to implement the built-in function "len()". Should return\n the length of the object, an integer ">=" 0. Also, an object that\n doesn\'t define a "__bool__()" method and whose "__len__()" method\n returns zero is considered to be false in a Boolean context.\n\nobject.__length_hint__(self)\n\n Called to implement "operator.length_hint()". Should return an\n estimated length for the object (which may be greater or less than\n the actual length). The length must be an integer ">=" 0. This\n method is purely an optimization and is never required for\n correctness.\n\n New in version 3.4.\n\nNote: Slicing is done exclusively with the following three methods. A\n call like\n\n a[1:2] = b\n\n is translated to\n\n a[slice(1, 2, None)] = b\n\n and so forth. Missing slice items are always filled in with "None".\n\nobject.__getitem__(self, key)\n\n Called to implement evaluation of "self[key]". For sequence types,\n the accepted keys should be integers and slice objects. Note that\n the special interpretation of negative indexes (if the class wishes\n to emulate a sequence type) is up to the "__getitem__()" method. If\n *key* is of an inappropriate type, "TypeError" may be raised; if of\n a value outside the set of indexes for the sequence (after any\n special interpretation of negative values), "IndexError" should be\n raised. For mapping types, if *key* is missing (not in the\n container), "KeyError" should be raised.\n\n Note: "for" loops expect that an "IndexError" will be raised for\n illegal indexes to allow proper detection of the end of the\n sequence.\n\nobject.__setitem__(self, key, value)\n\n Called to implement assignment to "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support changes to the values for keys, or if new keys\n can be added, or for sequences if elements can be replaced. The\n same exceptions should be raised for improper *key* values as for\n the "__getitem__()" method.\n\nobject.__delitem__(self, key)\n\n Called to implement deletion of "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support removal of keys, or for sequences if elements\n can be removed from the sequence. The same exceptions should be\n raised for improper *key* values as for the "__getitem__()" method.\n\nobject.__iter__(self)\n\n This method is called when an iterator is required for a container.\n This method should return a new iterator object that can iterate\n over all the objects in the container. For mappings, it should\n iterate over the keys of the container, and should also be made\n available as the method "keys()".\n\n Iterator objects also need to implement this method; they are\n required to return themselves. For more information on iterator\n objects, see *Iterator Types*.\n\nobject.__reversed__(self)\n\n Called (if present) by the "reversed()" built-in to implement\n reverse iteration. It should return a new iterator object that\n iterates over all the objects in the container in reverse order.\n\n If the "__reversed__()" method is not provided, the "reversed()"\n built-in will fall back to using the sequence protocol ("__len__()"\n and "__getitem__()"). Objects that support the sequence protocol\n should only provide "__reversed__()" if they can provide an\n implementation that is more efficient than the one provided by\n "reversed()".\n\nThe membership test operators ("in" and "not in") are normally\nimplemented as an iteration through a sequence. However, container\nobjects can supply the following special method with a more efficient\nimplementation, which also does not require the object be a sequence.\n\nobject.__contains__(self, item)\n\n Called to implement membership test operators. Should return true\n if *item* is in *self*, false otherwise. For mapping objects, this\n should consider the keys of the mapping rather than the values or\n the key-item pairs.\n\n For objects that don\'t define "__contains__()", the membership test\n first tries iteration via "__iter__()", then the old sequence\n iteration protocol via "__getitem__()", see *this section in the\n language reference*.\n', - 'shifting': '\nShifting operations\n*******************\n\nThe shifting operations have lower priority than the arithmetic\noperations:\n\n shift_expr ::= a_expr | shift_expr ( "<<" | ">>" ) a_expr\n\nThese operators accept integers as arguments. They shift the first\nargument to the left or right by the number of bits given by the\nsecond argument.\n\nA right shift by *n* bits is defined as floor division by "pow(2,n)".\nA left shift by *n* bits is defined as multiplication with "pow(2,n)".\n\nNote: In the current implementation, the right-hand operand is required to\n be at most "sys.maxsize". If the right-hand operand is larger than\n "sys.maxsize" an "OverflowError" exception is raised.\n', + 'sequence-types': '\nEmulating container types\n*************************\n\nThe following methods can be defined to implement container objects.\nContainers usually are sequences (such as lists or tuples) or mappings\n(like dictionaries), but can represent other containers as well. The\nfirst set of methods is used either to emulate a sequence or to\nemulate a mapping; the difference is that for a sequence, the\nallowable keys should be the integers *k* for which "0 <= k < N" where\n*N* is the length of the sequence, or slice objects, which define a\nrange of items. It is also recommended that mappings provide the\nmethods "keys()", "values()", "items()", "get()", "clear()",\n"setdefault()", "pop()", "popitem()", "copy()", and "update()"\nbehaving similar to those for Python\'s standard dictionary objects.\nThe "collections" module provides a "MutableMapping" abstract base\nclass to help create those methods from a base set of "__getitem__()",\n"__setitem__()", "__delitem__()", and "keys()". Mutable sequences\nshould provide methods "append()", "count()", "index()", "extend()",\n"insert()", "pop()", "remove()", "reverse()" and "sort()", like Python\nstandard list objects. Finally, sequence types should implement\naddition (meaning concatenation) and multiplication (meaning\nrepetition) by defining the methods "__add__()", "__radd__()",\n"__iadd__()", "__mul__()", "__rmul__()" and "__imul__()" described\nbelow; they should not define other numerical operators. It is\nrecommended that both mappings and sequences implement the\n"__contains__()" method to allow efficient use of the "in" operator;\nfor mappings, "in" should search the mapping\'s keys; for sequences, it\nshould search through the values. It is further recommended that both\nmappings and sequences implement the "__iter__()" method to allow\nefficient iteration through the container; for mappings, "__iter__()"\nshould be the same as "keys()"; for sequences, it should iterate\nthrough the values.\n\nobject.__len__(self)\n\n Called to implement the built-in function "len()". Should return\n the length of the object, an integer ">=" 0. Also, an object that\n doesn\'t define a "__bool__()" method and whose "__len__()" method\n returns zero is considered to be false in a Boolean context.\n\nobject.__length_hint__(self)\n\n Called to implement "operator.length_hint()". Should return an\n estimated length for the object (which may be greater or less than\n the actual length). The length must be an integer ">=" 0. This\n method is purely an optimization and is never required for\n correctness.\n\n New in version 3.4.\n\nNote: Slicing is done exclusively with the following three methods.\n A call like\n\n a[1:2] = b\n\n is translated to\n\n a[slice(1, 2, None)] = b\n\n and so forth. Missing slice items are always filled in with "None".\n\nobject.__getitem__(self, key)\n\n Called to implement evaluation of "self[key]". For sequence types,\n the accepted keys should be integers and slice objects. Note that\n the special interpretation of negative indexes (if the class wishes\n to emulate a sequence type) is up to the "__getitem__()" method. If\n *key* is of an inappropriate type, "TypeError" may be raised; if of\n a value outside the set of indexes for the sequence (after any\n special interpretation of negative values), "IndexError" should be\n raised. For mapping types, if *key* is missing (not in the\n container), "KeyError" should be raised.\n\n Note: "for" loops expect that an "IndexError" will be raised for\n illegal indexes to allow proper detection of the end of the\n sequence.\n\nobject.__setitem__(self, key, value)\n\n Called to implement assignment to "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support changes to the values for keys, or if new keys\n can be added, or for sequences if elements can be replaced. The\n same exceptions should be raised for improper *key* values as for\n the "__getitem__()" method.\n\nobject.__delitem__(self, key)\n\n Called to implement deletion of "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support removal of keys, or for sequences if elements\n can be removed from the sequence. The same exceptions should be\n raised for improper *key* values as for the "__getitem__()" method.\n\nobject.__iter__(self)\n\n This method is called when an iterator is required for a container.\n This method should return a new iterator object that can iterate\n over all the objects in the container. For mappings, it should\n iterate over the keys of the container, and should also be made\n available as the method "keys()".\n\n Iterator objects also need to implement this method; they are\n required to return themselves. For more information on iterator\n objects, see *Iterator Types*.\n\nobject.__reversed__(self)\n\n Called (if present) by the "reversed()" built-in to implement\n reverse iteration. It should return a new iterator object that\n iterates over all the objects in the container in reverse order.\n\n If the "__reversed__()" method is not provided, the "reversed()"\n built-in will fall back to using the sequence protocol ("__len__()"\n and "__getitem__()"). Objects that support the sequence protocol\n should only provide "__reversed__()" if they can provide an\n implementation that is more efficient than the one provided by\n "reversed()".\n\nThe membership test operators ("in" and "not in") are normally\nimplemented as an iteration through a sequence. However, container\nobjects can supply the following special method with a more efficient\nimplementation, which also does not require the object be a sequence.\n\nobject.__contains__(self, item)\n\n Called to implement membership test operators. Should return true\n if *item* is in *self*, false otherwise. For mapping objects, this\n should consider the keys of the mapping rather than the values or\n the key-item pairs.\n\n For objects that don\'t define "__contains__()", the membership test\n first tries iteration via "__iter__()", then the old sequence\n iteration protocol via "__getitem__()", see *this section in the\n language reference*.\n', + 'shifting': '\nShifting operations\n*******************\n\nThe shifting operations have lower priority than the arithmetic\noperations:\n\n shift_expr ::= a_expr | shift_expr ( "<<" | ">>" ) a_expr\n\nThese operators accept integers as arguments. They shift the first\nargument to the left or right by the number of bits given by the\nsecond argument.\n\nA right shift by *n* bits is defined as floor division by "pow(2,n)".\nA left shift by *n* bits is defined as multiplication with "pow(2,n)".\n\nNote: In the current implementation, the right-hand operand is\n required to be at most "sys.maxsize". If the right-hand operand is\n larger than "sys.maxsize" an "OverflowError" exception is raised.\n', 'slicings': '\nSlicings\n********\n\nA slicing selects a range of items in a sequence object (e.g., a\nstring, tuple or list). Slicings may be used as expressions or as\ntargets in assignment or "del" statements. The syntax for a slicing:\n\n slicing ::= primary "[" slice_list "]"\n slice_list ::= slice_item ("," slice_item)* [","]\n slice_item ::= expression | proper_slice\n proper_slice ::= [lower_bound] ":" [upper_bound] [ ":" [stride] ]\n lower_bound ::= expression\n upper_bound ::= expression\n stride ::= expression\n\nThere is ambiguity in the formal syntax here: anything that looks like\nan expression list also looks like a slice list, so any subscription\ncan be interpreted as a slicing. Rather than further complicating the\nsyntax, this is disambiguated by defining that in this case the\ninterpretation as a subscription takes priority over the\ninterpretation as a slicing (this is the case if the slice list\ncontains no proper slice).\n\nThe semantics for a slicing are as follows. The primary must evaluate\nto a mapping object, and it is indexed (using the same "__getitem__()"\nmethod as normal subscription) with a key that is constructed from the\nslice list, as follows. If the slice list contains at least one\ncomma, the key is a tuple containing the conversion of the slice\nitems; otherwise, the conversion of the lone slice item is the key.\nThe conversion of a slice item that is an expression is that\nexpression. The conversion of a proper slice is a slice object (see\nsection *The standard type hierarchy*) whose "start", "stop" and\n"step" attributes are the values of the expressions given as lower\nbound, upper bound and stride, respectively, substituting "None" for\nmissing expressions.\n', - 'specialattrs': '\nSpecial Attributes\n******************\n\nThe implementation adds a few special read-only attributes to several\nobject types, where they are relevant. Some of these are not reported\nby the "dir()" built-in function.\n\nobject.__dict__\n\n A dictionary or other mapping object used to store an object\'s\n (writable) attributes.\n\ninstance.__class__\n\n The class to which a class instance belongs.\n\nclass.__bases__\n\n The tuple of base classes of a class object.\n\nclass.__name__\n\n The name of the class or type.\n\nclass.__qualname__\n\n The *qualified name* of the class or type.\n\n New in version 3.3.\n\nclass.__mro__\n\n This attribute is a tuple of classes that are considered when\n looking for base classes during method resolution.\n\nclass.mro()\n\n This method can be overridden by a metaclass to customize the\n method resolution order for its instances. It is called at class\n instantiation, and its result is stored in "__mro__".\n\nclass.__subclasses__()\n\n Each class keeps a list of weak references to its immediate\n subclasses. This method returns a list of all those references\n still alive. Example:\n\n >>> int.__subclasses__()\n [<class \'bool\'>]\n\n-[ Footnotes ]-\n\n[1] Additional information on these special methods may be found in\n the Python Reference Manual (*Basic customization*).\n\n[2] As a consequence, the list "[1, 2]" is considered equal to "[1.0,\n 2.0]", and similarly for tuples.\n\n[3] They must have since the parser can\'t tell the type of the\n operands.\n\n[4] Cased characters are those with general category property being\n one of "Lu" (Letter, uppercase), "Ll" (Letter, lowercase), or "Lt"\n (Letter, titlecase).\n\n[5] To format only a tuple you should therefore provide a singleton\n tuple whose only element is the tuple to be formatted.\n', - 'specialnames': '\nSpecial method names\n********************\n\nA class can implement certain operations that are invoked by special\nsyntax (such as arithmetic operations or subscripting and slicing) by\ndefining methods with special names. This is Python\'s approach to\n*operator overloading*, allowing classes to define their own behavior\nwith respect to language operators. For instance, if a class defines\na method named "__getitem__()", and "x" is an instance of this class,\nthen "x[i]" is roughly equivalent to "type(x).__getitem__(x, i)".\nExcept where mentioned, attempts to execute an operation raise an\nexception when no appropriate method is defined (typically\n"AttributeError" or "TypeError").\n\nWhen implementing a class that emulates any built-in type, it is\nimportant that the emulation only be implemented to the degree that it\nmakes sense for the object being modelled. For example, some\nsequences may work well with retrieval of individual elements, but\nextracting a slice may not make sense. (One example of this is the\n"NodeList" interface in the W3C\'s Document Object Model.)\n\n\nBasic customization\n===================\n\nobject.__new__(cls[, ...])\n\n Called to create a new instance of class *cls*. "__new__()" is a\n static method (special-cased so you need not declare it as such)\n that takes the class of which an instance was requested as its\n first argument. The remaining arguments are those passed to the\n object constructor expression (the call to the class). The return\n value of "__new__()" should be the new object instance (usually an\n instance of *cls*).\n\n Typical implementations create a new instance of the class by\n invoking the superclass\'s "__new__()" method using\n "super(currentclass, cls).__new__(cls[, ...])" with appropriate\n arguments and then modifying the newly-created instance as\n necessary before returning it.\n\n If "__new__()" returns an instance of *cls*, then the new\n instance\'s "__init__()" method will be invoked like\n "__init__(self[, ...])", where *self* is the new instance and the\n remaining arguments are the same as were passed to "__new__()".\n\n If "__new__()" does not return an instance of *cls*, then the new\n instance\'s "__init__()" method will not be invoked.\n\n "__new__()" is intended mainly to allow subclasses of immutable\n types (like int, str, or tuple) to customize instance creation. It\n is also commonly overridden in custom metaclasses in order to\n customize class creation.\n\nobject.__init__(self[, ...])\n\n Called when the instance is created. The arguments are those\n passed to the class constructor expression. If a base class has an\n "__init__()" method, the derived class\'s "__init__()" method, if\n any, must explicitly call it to ensure proper initialization of the\n base class part of the instance; for example:\n "BaseClass.__init__(self, [args...])". As a special constraint on\n constructors, no value may be returned; doing so will cause a\n "TypeError" to be raised at runtime.\n\nobject.__del__(self)\n\n Called when the instance is about to be destroyed. This is also\n called a destructor. If a base class has a "__del__()" method, the\n derived class\'s "__del__()" method, if any, must explicitly call it\n to ensure proper deletion of the base class part of the instance.\n Note that it is possible (though not recommended!) for the\n "__del__()" method to postpone destruction of the instance by\n creating a new reference to it. It may then be called at a later\n time when this new reference is deleted. It is not guaranteed that\n "__del__()" methods are called for objects that still exist when\n the interpreter exits.\n\n Note: "del x" doesn\'t directly call "x.__del__()" --- the former\n decrements the reference count for "x" by one, and the latter is\n only called when "x"\'s reference count reaches zero. Some common\n situations that may prevent the reference count of an object from\n going to zero include: circular references between objects (e.g.,\n a doubly-linked list or a tree data structure with parent and\n child pointers); a reference to the object on the stack frame of\n a function that caught an exception (the traceback stored in\n "sys.exc_info()[2]" keeps the stack frame alive); or a reference\n to the object on the stack frame that raised an unhandled\n exception in interactive mode (the traceback stored in\n "sys.last_traceback" keeps the stack frame alive). The first\n situation can only be remedied by explicitly breaking the cycles;\n the latter two situations can be resolved by storing "None" in\n "sys.last_traceback". Circular references which are garbage are\n detected and cleaned up when the cyclic garbage collector is\n enabled (it\'s on by default). Refer to the documentation for the\n "gc" module for more information about this topic.\n\n Warning: Due to the precarious circumstances under which "__del__()"\n methods are invoked, exceptions that occur during their execution\n are ignored, and a warning is printed to "sys.stderr" instead.\n Also, when "__del__()" is invoked in response to a module being\n deleted (e.g., when execution of the program is done), other\n globals referenced by the "__del__()" method may already have\n been deleted or in the process of being torn down (e.g. the\n import machinery shutting down). For this reason, "__del__()"\n methods should do the absolute minimum needed to maintain\n external invariants. Starting with version 1.5, Python\n guarantees that globals whose name begins with a single\n underscore are deleted from their module before other globals are\n deleted; if no other references to such globals exist, this may\n help in assuring that imported modules are still available at the\n time when the "__del__()" method is called.\n\nobject.__repr__(self)\n\n Called by the "repr()" built-in function to compute the "official"\n string representation of an object. If at all possible, this\n should look like a valid Python expression that could be used to\n recreate an object with the same value (given an appropriate\n environment). If this is not possible, a string of the form\n "<...some useful description...>" should be returned. The return\n value must be a string object. If a class defines "__repr__()" but\n not "__str__()", then "__repr__()" is also used when an "informal"\n string representation of instances of that class is required.\n\n This is typically used for debugging, so it is important that the\n representation is information-rich and unambiguous.\n\nobject.__str__(self)\n\n Called by "str(object)" and the built-in functions "format()" and\n "print()" to compute the "informal" or nicely printable string\n representation of an object. The return value must be a *string*\n object.\n\n This method differs from "object.__repr__()" in that there is no\n expectation that "__str__()" return a valid Python expression: a\n more convenient or concise representation can be used.\n\n The default implementation defined by the built-in type "object"\n calls "object.__repr__()".\n\nobject.__bytes__(self)\n\n Called by "bytes()" to compute a byte-string representation of an\n object. This should return a "bytes" object.\n\nobject.__format__(self, format_spec)\n\n Called by the "format()" built-in function (and by extension, the\n "str.format()" method of class "str") to produce a "formatted"\n string representation of an object. The "format_spec" argument is a\n string that contains a description of the formatting options\n desired. The interpretation of the "format_spec" argument is up to\n the type implementing "__format__()", however most classes will\n either delegate formatting to one of the built-in types, or use a\n similar formatting option syntax.\n\n See *Format Specification Mini-Language* for a description of the\n standard formatting syntax.\n\n The return value must be a string object.\n\n Changed in version 3.4: The __format__ method of "object" itself\n raises a "TypeError" if passed any non-empty string.\n\nobject.__lt__(self, other)\nobject.__le__(self, other)\nobject.__eq__(self, other)\nobject.__ne__(self, other)\nobject.__gt__(self, other)\nobject.__ge__(self, other)\n\n These are the so-called "rich comparison" methods. The\n correspondence between operator symbols and method names is as\n follows: "x<y" calls "x.__lt__(y)", "x<=y" calls "x.__le__(y)",\n "x==y" calls "x.__eq__(y)", "x!=y" calls "x.__ne__(y)", "x>y" calls\n "x.__gt__(y)", and "x>=y" calls "x.__ge__(y)".\n\n A rich comparison method may return the singleton "NotImplemented"\n if it does not implement the operation for a given pair of\n arguments. By convention, "False" and "True" are returned for a\n successful comparison. However, these methods can return any value,\n so if the comparison operator is used in a Boolean context (e.g.,\n in the condition of an "if" statement), Python will call "bool()"\n on the value to determine if the result is true or false.\n\n There are no implied relationships among the comparison operators.\n The truth of "x==y" does not imply that "x!=y" is false.\n Accordingly, when defining "__eq__()", one should also define\n "__ne__()" so that the operators will behave as expected. See the\n paragraph on "__hash__()" for some important notes on creating\n *hashable* objects which support custom comparison operations and\n are usable as dictionary keys.\n\n There are no swapped-argument versions of these methods (to be used\n when the left argument does not support the operation but the right\n argument does); rather, "__lt__()" and "__gt__()" are each other\'s\n reflection, "__le__()" and "__ge__()" are each other\'s reflection,\n and "__eq__()" and "__ne__()" are their own reflection.\n\n Arguments to rich comparison methods are never coerced.\n\n To automatically generate ordering operations from a single root\n operation, see "functools.total_ordering()".\n\nobject.__hash__(self)\n\n Called by built-in function "hash()" and for operations on members\n of hashed collections including "set", "frozenset", and "dict".\n "__hash__()" should return an integer. The only required property\n is that objects which compare equal have the same hash value; it is\n advised to somehow mix together (e.g. using exclusive or) the hash\n values for the components of the object that also play a part in\n comparison of objects.\n\n Note: "hash()" truncates the value returned from an object\'s custom\n "__hash__()" method to the size of a "Py_ssize_t". This is\n typically 8 bytes on 64-bit builds and 4 bytes on 32-bit builds.\n If an object\'s "__hash__()" must interoperate on builds of\n different bit sizes, be sure to check the width on all supported\n builds. An easy way to do this is with "python -c "import sys;\n print(sys.hash_info.width)""\n\n If a class does not define an "__eq__()" method it should not\n define a "__hash__()" operation either; if it defines "__eq__()"\n but not "__hash__()", its instances will not be usable as items in\n hashable collections. If a class defines mutable objects and\n implements an "__eq__()" method, it should not implement\n "__hash__()", since the implementation of hashable collections\n requires that a key\'s hash value is immutable (if the object\'s hash\n value changes, it will be in the wrong hash bucket).\n\n User-defined classes have "__eq__()" and "__hash__()" methods by\n default; with them, all objects compare unequal (except with\n themselves) and "x.__hash__()" returns an appropriate value such\n that "x == y" implies both that "x is y" and "hash(x) == hash(y)".\n\n A class that overrides "__eq__()" and does not define "__hash__()"\n will have its "__hash__()" implicitly set to "None". When the\n "__hash__()" method of a class is "None", instances of the class\n will raise an appropriate "TypeError" when a program attempts to\n retrieve their hash value, and will also be correctly identified as\n unhashable when checking "isinstance(obj, collections.Hashable").\n\n If a class that overrides "__eq__()" needs to retain the\n implementation of "__hash__()" from a parent class, the interpreter\n must be told this explicitly by setting "__hash__ =\n <ParentClass>.__hash__".\n\n If a class that does not override "__eq__()" wishes to suppress\n hash support, it should include "__hash__ = None" in the class\n definition. A class which defines its own "__hash__()" that\n explicitly raises a "TypeError" would be incorrectly identified as\n hashable by an "isinstance(obj, collections.Hashable)" call.\n\n Note: By default, the "__hash__()" values of str, bytes and datetime\n objects are "salted" with an unpredictable random value.\n Although they remain constant within an individual Python\n process, they are not predictable between repeated invocations of\n Python.This is intended to provide protection against a denial-\n of-service caused by carefully-chosen inputs that exploit the\n worst case performance of a dict insertion, O(n^2) complexity.\n See http://www.ocert.org/advisories/ocert-2011-003.html for\n details.Changing hash values affects the iteration order of\n dicts, sets and other mappings. Python has never made guarantees\n about this ordering (and it typically varies between 32-bit and\n 64-bit builds).See also "PYTHONHASHSEED".\n\n Changed in version 3.3: Hash randomization is enabled by default.\n\nobject.__bool__(self)\n\n Called to implement truth value testing and the built-in operation\n "bool()"; should return "False" or "True". When this method is not\n defined, "__len__()" is called, if it is defined, and the object is\n considered true if its result is nonzero. If a class defines\n neither "__len__()" nor "__bool__()", all its instances are\n considered true.\n\n\nCustomizing attribute access\n============================\n\nThe following methods can be defined to customize the meaning of\nattribute access (use of, assignment to, or deletion of "x.name") for\nclass instances.\n\nobject.__getattr__(self, name)\n\n Called when an attribute lookup has not found the attribute in the\n usual places (i.e. it is not an instance attribute nor is it found\n in the class tree for "self"). "name" is the attribute name. This\n method should return the (computed) attribute value or raise an\n "AttributeError" exception.\n\n Note that if the attribute is found through the normal mechanism,\n "__getattr__()" is not called. (This is an intentional asymmetry\n between "__getattr__()" and "__setattr__()".) This is done both for\n efficiency reasons and because otherwise "__getattr__()" would have\n no way to access other attributes of the instance. Note that at\n least for instance variables, you can fake total control by not\n inserting any values in the instance attribute dictionary (but\n instead inserting them in another object). See the\n "__getattribute__()" method below for a way to actually get total\n control over attribute access.\n\nobject.__getattribute__(self, name)\n\n Called unconditionally to implement attribute accesses for\n instances of the class. If the class also defines "__getattr__()",\n the latter will not be called unless "__getattribute__()" either\n calls it explicitly or raises an "AttributeError". This method\n should return the (computed) attribute value or raise an\n "AttributeError" exception. In order to avoid infinite recursion in\n this method, its implementation should always call the base class\n method with the same name to access any attributes it needs, for\n example, "object.__getattribute__(self, name)".\n\n Note: This method may still be bypassed when looking up special methods\n as the result of implicit invocation via language syntax or\n built-in functions. See *Special method lookup*.\n\nobject.__setattr__(self, name, value)\n\n Called when an attribute assignment is attempted. This is called\n instead of the normal mechanism (i.e. store the value in the\n instance dictionary). *name* is the attribute name, *value* is the\n value to be assigned to it.\n\n If "__setattr__()" wants to assign to an instance attribute, it\n should call the base class method with the same name, for example,\n "object.__setattr__(self, name, value)".\n\nobject.__delattr__(self, name)\n\n Like "__setattr__()" but for attribute deletion instead of\n assignment. This should only be implemented if "del obj.name" is\n meaningful for the object.\n\nobject.__dir__(self)\n\n Called when "dir()" is called on the object. A sequence must be\n returned. "dir()" converts the returned sequence to a list and\n sorts it.\n\n\nImplementing Descriptors\n------------------------\n\nThe following methods only apply when an instance of the class\ncontaining the method (a so-called *descriptor* class) appears in an\n*owner* class (the descriptor must be in either the owner\'s class\ndictionary or in the class dictionary for one of its parents). In the\nexamples below, "the attribute" refers to the attribute whose name is\nthe key of the property in the owner class\' "__dict__".\n\nobject.__get__(self, instance, owner)\n\n Called to get the attribute of the owner class (class attribute\n access) or of an instance of that class (instance attribute\n access). *owner* is always the owner class, while *instance* is the\n instance that the attribute was accessed through, or "None" when\n the attribute is accessed through the *owner*. This method should\n return the (computed) attribute value or raise an "AttributeError"\n exception.\n\nobject.__set__(self, instance, value)\n\n Called to set the attribute on an instance *instance* of the owner\n class to a new value, *value*.\n\nobject.__delete__(self, instance)\n\n Called to delete the attribute on an instance *instance* of the\n owner class.\n\nThe attribute "__objclass__" is interpreted by the "inspect" module as\nspecifying the class where this object was defined (setting this\nappropriately can assist in runtime introspection of dynamic class\nattributes). For callables, it may indicate that an instance of the\ngiven type (or a subclass) is expected or required as the first\npositional argument (for example, CPython sets this attribute for\nunbound methods that are implemented in C).\n\n\nInvoking Descriptors\n--------------------\n\nIn general, a descriptor is an object attribute with "binding\nbehavior", one whose attribute access has been overridden by methods\nin the descriptor protocol: "__get__()", "__set__()", and\n"__delete__()". If any of those methods are defined for an object, it\nis said to be a descriptor.\n\nThe default behavior for attribute access is to get, set, or delete\nthe attribute from an object\'s dictionary. For instance, "a.x" has a\nlookup chain starting with "a.__dict__[\'x\']", then\n"type(a).__dict__[\'x\']", and continuing through the base classes of\n"type(a)" excluding metaclasses.\n\nHowever, if the looked-up value is an object defining one of the\ndescriptor methods, then Python may override the default behavior and\ninvoke the descriptor method instead. Where this occurs in the\nprecedence chain depends on which descriptor methods were defined and\nhow they were called.\n\nThe starting point for descriptor invocation is a binding, "a.x". How\nthe arguments are assembled depends on "a":\n\nDirect Call\n The simplest and least common call is when user code directly\n invokes a descriptor method: "x.__get__(a)".\n\nInstance Binding\n If binding to an object instance, "a.x" is transformed into the\n call: "type(a).__dict__[\'x\'].__get__(a, type(a))".\n\nClass Binding\n If binding to a class, "A.x" is transformed into the call:\n "A.__dict__[\'x\'].__get__(None, A)".\n\nSuper Binding\n If "a" is an instance of "super", then the binding "super(B,\n obj).m()" searches "obj.__class__.__mro__" for the base class "A"\n immediately preceding "B" and then invokes the descriptor with the\n call: "A.__dict__[\'m\'].__get__(obj, obj.__class__)".\n\nFor instance bindings, the precedence of descriptor invocation depends\non the which descriptor methods are defined. A descriptor can define\nany combination of "__get__()", "__set__()" and "__delete__()". If it\ndoes not define "__get__()", then accessing the attribute will return\nthe descriptor object itself unless there is a value in the object\'s\ninstance dictionary. If the descriptor defines "__set__()" and/or\n"__delete__()", it is a data descriptor; if it defines neither, it is\na non-data descriptor. Normally, data descriptors define both\n"__get__()" and "__set__()", while non-data descriptors have just the\n"__get__()" method. Data descriptors with "__set__()" and "__get__()"\ndefined always override a redefinition in an instance dictionary. In\ncontrast, non-data descriptors can be overridden by instances.\n\nPython methods (including "staticmethod()" and "classmethod()") are\nimplemented as non-data descriptors. Accordingly, instances can\nredefine and override methods. This allows individual instances to\nacquire behaviors that differ from other instances of the same class.\n\nThe "property()" function is implemented as a data descriptor.\nAccordingly, instances cannot override the behavior of a property.\n\n\n__slots__\n---------\n\nBy default, instances of classes have a dictionary for attribute\nstorage. This wastes space for objects having very few instance\nvariables. The space consumption can become acute when creating large\nnumbers of instances.\n\nThe default can be overridden by defining *__slots__* in a class\ndefinition. The *__slots__* declaration takes a sequence of instance\nvariables and reserves just enough space in each instance to hold a\nvalue for each variable. Space is saved because *__dict__* is not\ncreated for each instance.\n\nobject.__slots__\n\n This class variable can be assigned a string, iterable, or sequence\n of strings with variable names used by instances. If defined in a\n class, *__slots__* reserves space for the declared variables and\n prevents the automatic creation of *__dict__* and *__weakref__* for\n each instance.\n\n\nNotes on using *__slots__*\n~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n* When inheriting from a class without *__slots__*, the *__dict__*\n attribute of that class will always be accessible, so a *__slots__*\n definition in the subclass is meaningless.\n\n* Without a *__dict__* variable, instances cannot be assigned new\n variables not listed in the *__slots__* definition. Attempts to\n assign to an unlisted variable name raises "AttributeError". If\n dynamic assignment of new variables is desired, then add\n "\'__dict__\'" to the sequence of strings in the *__slots__*\n declaration.\n\n* Without a *__weakref__* variable for each instance, classes defining\n *__slots__* do not support weak references to its instances. If weak\n reference support is needed, then add "\'__weakref__\'" to the\n sequence of strings in the *__slots__* declaration.\n\n* *__slots__* are implemented at the class level by creating\n descriptors (*Implementing Descriptors*) for each variable name. As\n a result, class attributes cannot be used to set default values for\n instance variables defined by *__slots__*; otherwise, the class\n attribute would overwrite the descriptor assignment.\n\n* The action of a *__slots__* declaration is limited to the class\n where it is defined. As a result, subclasses will have a *__dict__*\n unless they also define *__slots__* (which must only contain names\n of any *additional* slots).\n\n* If a class defines a slot also defined in a base class, the instance\n variable defined by the base class slot is inaccessible (except by\n retrieving its descriptor directly from the base class). This\n renders the meaning of the program undefined. In the future, a\n check may be added to prevent this.\n\n* Nonempty *__slots__* does not work for classes derived from\n "variable-length" built-in types such as "int", "bytes" and "tuple".\n\n* Any non-string iterable may be assigned to *__slots__*. Mappings may\n also be used; however, in the future, special meaning may be\n assigned to the values corresponding to each key.\n\n* *__class__* assignment works only if both classes have the same\n *__slots__*.\n\n\nCustomizing class creation\n==========================\n\nBy default, classes are constructed using "type()". The class body is\nexecuted in a new namespace and the class name is bound locally to the\nresult of "type(name, bases, namespace)".\n\nThe class creation process can be customised by passing the\n"metaclass" keyword argument in the class definition line, or by\ninheriting from an existing class that included such an argument. In\nthe following example, both "MyClass" and "MySubclass" are instances\nof "Meta":\n\n class Meta(type):\n pass\n\n class MyClass(metaclass=Meta):\n pass\n\n class MySubclass(MyClass):\n pass\n\nAny other keyword arguments that are specified in the class definition\nare passed through to all metaclass operations described below.\n\nWhen a class definition is executed, the following steps occur:\n\n* the appropriate metaclass is determined\n\n* the class namespace is prepared\n\n* the class body is executed\n\n* the class object is created\n\n\nDetermining the appropriate metaclass\n-------------------------------------\n\nThe appropriate metaclass for a class definition is determined as\nfollows:\n\n* if no bases and no explicit metaclass are given, then "type()" is\n used\n\n* if an explicit metaclass is given and it is *not* an instance of\n "type()", then it is used directly as the metaclass\n\n* if an instance of "type()" is given as the explicit metaclass, or\n bases are defined, then the most derived metaclass is used\n\nThe most derived metaclass is selected from the explicitly specified\nmetaclass (if any) and the metaclasses (i.e. "type(cls)") of all\nspecified base classes. The most derived metaclass is one which is a\nsubtype of *all* of these candidate metaclasses. If none of the\ncandidate metaclasses meets that criterion, then the class definition\nwill fail with "TypeError".\n\n\nPreparing the class namespace\n-----------------------------\n\nOnce the appropriate metaclass has been identified, then the class\nnamespace is prepared. If the metaclass has a "__prepare__" attribute,\nit is called as "namespace = metaclass.__prepare__(name, bases,\n**kwds)" (where the additional keyword arguments, if any, come from\nthe class definition).\n\nIf the metaclass has no "__prepare__" attribute, then the class\nnamespace is initialised as an empty "dict()" instance.\n\nSee also:\n\n **PEP 3115** - Metaclasses in Python 3000\n Introduced the "__prepare__" namespace hook\n\n\nExecuting the class body\n------------------------\n\nThe class body is executed (approximately) as "exec(body, globals(),\nnamespace)". The key difference from a normal call to "exec()" is that\nlexical scoping allows the class body (including any methods) to\nreference names from the current and outer scopes when the class\ndefinition occurs inside a function.\n\nHowever, even when the class definition occurs inside the function,\nmethods defined inside the class still cannot see names defined at the\nclass scope. Class variables must be accessed through the first\nparameter of instance or class methods, and cannot be accessed at all\nfrom static methods.\n\n\nCreating the class object\n-------------------------\n\nOnce the class namespace has been populated by executing the class\nbody, the class object is created by calling "metaclass(name, bases,\nnamespace, **kwds)" (the additional keywords passed here are the same\nas those passed to "__prepare__").\n\nThis class object is the one that will be referenced by the zero-\nargument form of "super()". "__class__" is an implicit closure\nreference created by the compiler if any methods in a class body refer\nto either "__class__" or "super". This allows the zero argument form\nof "super()" to correctly identify the class being defined based on\nlexical scoping, while the class or instance that was used to make the\ncurrent call is identified based on the first argument passed to the\nmethod.\n\nAfter the class object is created, it is passed to the class\ndecorators included in the class definition (if any) and the resulting\nobject is bound in the local namespace as the defined class.\n\nSee also:\n\n **PEP 3135** - New super\n Describes the implicit "__class__" closure reference\n\n\nMetaclass example\n-----------------\n\nThe potential uses for metaclasses are boundless. Some ideas that have\nbeen explored include logging, interface checking, automatic\ndelegation, automatic property creation, proxies, frameworks, and\nautomatic resource locking/synchronization.\n\nHere is an example of a metaclass that uses an\n"collections.OrderedDict" to remember the order that class members\nwere defined:\n\n class OrderedClass(type):\n\n @classmethod\n def __prepare__(metacls, name, bases, **kwds):\n return collections.OrderedDict()\n\n def __new__(cls, name, bases, namespace, **kwds):\n result = type.__new__(cls, name, bases, dict(namespace))\n result.members = tuple(namespace)\n return result\n\n class A(metaclass=OrderedClass):\n def one(self): pass\n def two(self): pass\n def three(self): pass\n def four(self): pass\n\n >>> A.members\n (\'__module__\', \'one\', \'two\', \'three\', \'four\')\n\nWhen the class definition for *A* gets executed, the process begins\nwith calling the metaclass\'s "__prepare__()" method which returns an\nempty "collections.OrderedDict". That mapping records the methods and\nattributes of *A* as they are defined within the body of the class\nstatement. Once those definitions are executed, the ordered dictionary\nis fully populated and the metaclass\'s "__new__()" method gets\ninvoked. That method builds the new type and it saves the ordered\ndictionary keys in an attribute called "members".\n\n\nCustomizing instance and subclass checks\n========================================\n\nThe following methods are used to override the default behavior of the\n"isinstance()" and "issubclass()" built-in functions.\n\nIn particular, the metaclass "abc.ABCMeta" implements these methods in\norder to allow the addition of Abstract Base Classes (ABCs) as\n"virtual base classes" to any class or type (including built-in\ntypes), including other ABCs.\n\nclass.__instancecheck__(self, instance)\n\n Return true if *instance* should be considered a (direct or\n indirect) instance of *class*. If defined, called to implement\n "isinstance(instance, class)".\n\nclass.__subclasscheck__(self, subclass)\n\n Return true if *subclass* should be considered a (direct or\n indirect) subclass of *class*. If defined, called to implement\n "issubclass(subclass, class)".\n\nNote that these methods are looked up on the type (metaclass) of a\nclass. They cannot be defined as class methods in the actual class.\nThis is consistent with the lookup of special methods that are called\non instances, only in this case the instance is itself a class.\n\nSee also:\n\n **PEP 3119** - Introducing Abstract Base Classes\n Includes the specification for customizing "isinstance()" and\n "issubclass()" behavior through "__instancecheck__()" and\n "__subclasscheck__()", with motivation for this functionality in\n the context of adding Abstract Base Classes (see the "abc"\n module) to the language.\n\n\nEmulating callable objects\n==========================\n\nobject.__call__(self[, args...])\n\n Called when the instance is "called" as a function; if this method\n is defined, "x(arg1, arg2, ...)" is a shorthand for\n "x.__call__(arg1, arg2, ...)".\n\n\nEmulating container types\n=========================\n\nThe following methods can be defined to implement container objects.\nContainers usually are sequences (such as lists or tuples) or mappings\n(like dictionaries), but can represent other containers as well. The\nfirst set of methods is used either to emulate a sequence or to\nemulate a mapping; the difference is that for a sequence, the\nallowable keys should be the integers *k* for which "0 <= k < N" where\n*N* is the length of the sequence, or slice objects, which define a\nrange of items. It is also recommended that mappings provide the\nmethods "keys()", "values()", "items()", "get()", "clear()",\n"setdefault()", "pop()", "popitem()", "copy()", and "update()"\nbehaving similar to those for Python\'s standard dictionary objects.\nThe "collections" module provides a "MutableMapping" abstract base\nclass to help create those methods from a base set of "__getitem__()",\n"__setitem__()", "__delitem__()", and "keys()". Mutable sequences\nshould provide methods "append()", "count()", "index()", "extend()",\n"insert()", "pop()", "remove()", "reverse()" and "sort()", like Python\nstandard list objects. Finally, sequence types should implement\naddition (meaning concatenation) and multiplication (meaning\nrepetition) by defining the methods "__add__()", "__radd__()",\n"__iadd__()", "__mul__()", "__rmul__()" and "__imul__()" described\nbelow; they should not define other numerical operators. It is\nrecommended that both mappings and sequences implement the\n"__contains__()" method to allow efficient use of the "in" operator;\nfor mappings, "in" should search the mapping\'s keys; for sequences, it\nshould search through the values. It is further recommended that both\nmappings and sequences implement the "__iter__()" method to allow\nefficient iteration through the container; for mappings, "__iter__()"\nshould be the same as "keys()"; for sequences, it should iterate\nthrough the values.\n\nobject.__len__(self)\n\n Called to implement the built-in function "len()". Should return\n the length of the object, an integer ">=" 0. Also, an object that\n doesn\'t define a "__bool__()" method and whose "__len__()" method\n returns zero is considered to be false in a Boolean context.\n\nobject.__length_hint__(self)\n\n Called to implement "operator.length_hint()". Should return an\n estimated length for the object (which may be greater or less than\n the actual length). The length must be an integer ">=" 0. This\n method is purely an optimization and is never required for\n correctness.\n\n New in version 3.4.\n\nNote: Slicing is done exclusively with the following three methods. A\n call like\n\n a[1:2] = b\n\n is translated to\n\n a[slice(1, 2, None)] = b\n\n and so forth. Missing slice items are always filled in with "None".\n\nobject.__getitem__(self, key)\n\n Called to implement evaluation of "self[key]". For sequence types,\n the accepted keys should be integers and slice objects. Note that\n the special interpretation of negative indexes (if the class wishes\n to emulate a sequence type) is up to the "__getitem__()" method. If\n *key* is of an inappropriate type, "TypeError" may be raised; if of\n a value outside the set of indexes for the sequence (after any\n special interpretation of negative values), "IndexError" should be\n raised. For mapping types, if *key* is missing (not in the\n container), "KeyError" should be raised.\n\n Note: "for" loops expect that an "IndexError" will be raised for\n illegal indexes to allow proper detection of the end of the\n sequence.\n\nobject.__setitem__(self, key, value)\n\n Called to implement assignment to "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support changes to the values for keys, or if new keys\n can be added, or for sequences if elements can be replaced. The\n same exceptions should be raised for improper *key* values as for\n the "__getitem__()" method.\n\nobject.__delitem__(self, key)\n\n Called to implement deletion of "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support removal of keys, or for sequences if elements\n can be removed from the sequence. The same exceptions should be\n raised for improper *key* values as for the "__getitem__()" method.\n\nobject.__iter__(self)\n\n This method is called when an iterator is required for a container.\n This method should return a new iterator object that can iterate\n over all the objects in the container. For mappings, it should\n iterate over the keys of the container, and should also be made\n available as the method "keys()".\n\n Iterator objects also need to implement this method; they are\n required to return themselves. For more information on iterator\n objects, see *Iterator Types*.\n\nobject.__reversed__(self)\n\n Called (if present) by the "reversed()" built-in to implement\n reverse iteration. It should return a new iterator object that\n iterates over all the objects in the container in reverse order.\n\n If the "__reversed__()" method is not provided, the "reversed()"\n built-in will fall back to using the sequence protocol ("__len__()"\n and "__getitem__()"). Objects that support the sequence protocol\n should only provide "__reversed__()" if they can provide an\n implementation that is more efficient than the one provided by\n "reversed()".\n\nThe membership test operators ("in" and "not in") are normally\nimplemented as an iteration through a sequence. However, container\nobjects can supply the following special method with a more efficient\nimplementation, which also does not require the object be a sequence.\n\nobject.__contains__(self, item)\n\n Called to implement membership test operators. Should return true\n if *item* is in *self*, false otherwise. For mapping objects, this\n should consider the keys of the mapping rather than the values or\n the key-item pairs.\n\n For objects that don\'t define "__contains__()", the membership test\n first tries iteration via "__iter__()", then the old sequence\n iteration protocol via "__getitem__()", see *this section in the\n language reference*.\n\n\nEmulating numeric types\n=======================\n\nThe following methods can be defined to emulate numeric objects.\nMethods corresponding to operations that are not supported by the\nparticular kind of number implemented (e.g., bitwise operations for\nnon-integral numbers) should be left undefined.\n\nobject.__add__(self, other)\nobject.__sub__(self, other)\nobject.__mul__(self, other)\nobject.__truediv__(self, other)\nobject.__floordiv__(self, other)\nobject.__mod__(self, other)\nobject.__divmod__(self, other)\nobject.__pow__(self, other[, modulo])\nobject.__lshift__(self, other)\nobject.__rshift__(self, other)\nobject.__and__(self, other)\nobject.__xor__(self, other)\nobject.__or__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|"). For instance, to evaluate the\n expression "x + y", where *x* is an instance of a class that has an\n "__add__()" method, "x.__add__(y)" is called. The "__divmod__()"\n method should be the equivalent to using "__floordiv__()" and\n "__mod__()"; it should not be related to "__truediv__()". Note\n that "__pow__()" should be defined to accept an optional third\n argument if the ternary version of the built-in "pow()" function is\n to be supported.\n\n If one of those methods does not support the operation with the\n supplied arguments, it should return "NotImplemented".\n\nobject.__radd__(self, other)\nobject.__rsub__(self, other)\nobject.__rmul__(self, other)\nobject.__rtruediv__(self, other)\nobject.__rfloordiv__(self, other)\nobject.__rmod__(self, other)\nobject.__rdivmod__(self, other)\nobject.__rpow__(self, other)\nobject.__rlshift__(self, other)\nobject.__rrshift__(self, other)\nobject.__rand__(self, other)\nobject.__rxor__(self, other)\nobject.__ror__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|") with reflected (swapped) operands.\n These functions are only called if the left operand does not\n support the corresponding operation and the operands are of\n different types. [2] For instance, to evaluate the expression "x -\n y", where *y* is an instance of a class that has an "__rsub__()"\n method, "y.__rsub__(x)" is called if "x.__sub__(y)" returns\n *NotImplemented*.\n\n Note that ternary "pow()" will not try calling "__rpow__()" (the\n coercion rules would become too complicated).\n\n Note: If the right operand\'s type is a subclass of the left operand\'s\n type and that subclass provides the reflected method for the\n operation, this method will be called before the left operand\'s\n non-reflected method. This behavior allows subclasses to\n override their ancestors\' operations.\n\nobject.__iadd__(self, other)\nobject.__isub__(self, other)\nobject.__imul__(self, other)\nobject.__itruediv__(self, other)\nobject.__ifloordiv__(self, other)\nobject.__imod__(self, other)\nobject.__ipow__(self, other[, modulo])\nobject.__ilshift__(self, other)\nobject.__irshift__(self, other)\nobject.__iand__(self, other)\nobject.__ixor__(self, other)\nobject.__ior__(self, other)\n\n These methods are called to implement the augmented arithmetic\n assignments ("+=", "-=", "*=", "/=", "//=", "%=", "**=", "<<=",\n ">>=", "&=", "^=", "|="). These methods should attempt to do the\n operation in-place (modifying *self*) and return the result (which\n could be, but does not have to be, *self*). If a specific method\n is not defined, the augmented assignment falls back to the normal\n methods. For instance, if *x* is an instance of a class with an\n "__iadd__()" method, "x += y" is equivalent to "x = x.__iadd__(y)"\n . Otherwise, "x.__add__(y)" and "y.__radd__(x)" are considered, as\n with the evaluation of "x + y". In certain situations, augmented\n assignment can result in unexpected errors (see *Why does\n a_tuple[i] += [\'item\'] raise an exception when the addition\n works?*), but this behavior is in fact part of the data model.\n\nobject.__neg__(self)\nobject.__pos__(self)\nobject.__abs__(self)\nobject.__invert__(self)\n\n Called to implement the unary arithmetic operations ("-", "+",\n "abs()" and "~").\n\nobject.__complex__(self)\nobject.__int__(self)\nobject.__float__(self)\nobject.__round__(self[, n])\n\n Called to implement the built-in functions "complex()", "int()",\n "float()" and "round()". Should return a value of the appropriate\n type.\n\nobject.__index__(self)\n\n Called to implement "operator.index()", and whenever Python needs\n to losslessly convert the numeric object to an integer object (such\n as in slicing, or in the built-in "bin()", "hex()" and "oct()"\n functions). Presence of this method indicates that the numeric\n object is an integer type. Must return an integer.\n\n Note: When "__index__()" is defined, "__int__()" should also be\n defined, and both shuld return the same value, in order to have a\n coherent integer type class.\n\n\nWith Statement Context Managers\n===============================\n\nA *context manager* is an object that defines the runtime context to\nbe established when executing a "with" statement. The context manager\nhandles the entry into, and the exit from, the desired runtime context\nfor the execution of the block of code. Context managers are normally\ninvoked using the "with" statement (described in section *The with\nstatement*), but can also be used by directly invoking their methods.\n\nTypical uses of context managers include saving and restoring various\nkinds of global state, locking and unlocking resources, closing opened\nfiles, etc.\n\nFor more information on context managers, see *Context Manager Types*.\n\nobject.__enter__(self)\n\n Enter the runtime context related to this object. The "with"\n statement will bind this method\'s return value to the target(s)\n specified in the "as" clause of the statement, if any.\n\nobject.__exit__(self, exc_type, exc_value, traceback)\n\n Exit the runtime context related to this object. The parameters\n describe the exception that caused the context to be exited. If the\n context was exited without an exception, all three arguments will\n be "None".\n\n If an exception is supplied, and the method wishes to suppress the\n exception (i.e., prevent it from being propagated), it should\n return a true value. Otherwise, the exception will be processed\n normally upon exit from this method.\n\n Note that "__exit__()" methods should not reraise the passed-in\n exception; this is the caller\'s responsibility.\n\nSee also:\n\n **PEP 0343** - The "with" statement\n The specification, background, and examples for the Python\n "with" statement.\n\n\nSpecial method lookup\n=====================\n\nFor custom classes, implicit invocations of special methods are only\nguaranteed to work correctly if defined on an object\'s type, not in\nthe object\'s instance dictionary. That behaviour is the reason why\nthe following code raises an exception:\n\n >>> class C:\n ... pass\n ...\n >>> c = C()\n >>> c.__len__ = lambda: 5\n >>> len(c)\n Traceback (most recent call last):\n File "<stdin>", line 1, in <module>\n TypeError: object of type \'C\' has no len()\n\nThe rationale behind this behaviour lies with a number of special\nmethods such as "__hash__()" and "__repr__()" that are implemented by\nall objects, including type objects. If the implicit lookup of these\nmethods used the conventional lookup process, they would fail when\ninvoked on the type object itself:\n\n >>> 1 .__hash__() == hash(1)\n True\n >>> int.__hash__() == hash(int)\n Traceback (most recent call last):\n File "<stdin>", line 1, in <module>\n TypeError: descriptor \'__hash__\' of \'int\' object needs an argument\n\nIncorrectly attempting to invoke an unbound method of a class in this\nway is sometimes referred to as \'metaclass confusion\', and is avoided\nby bypassing the instance when looking up special methods:\n\n >>> type(1).__hash__(1) == hash(1)\n True\n >>> type(int).__hash__(int) == hash(int)\n True\n\nIn addition to bypassing any instance attributes in the interest of\ncorrectness, implicit special method lookup generally also bypasses\nthe "__getattribute__()" method even of the object\'s metaclass:\n\n >>> class Meta(type):\n ... def __getattribute__(*args):\n ... print("Metaclass getattribute invoked")\n ... return type.__getattribute__(*args)\n ...\n >>> class C(object, metaclass=Meta):\n ... def __len__(self):\n ... return 10\n ... def __getattribute__(*args):\n ... print("Class getattribute invoked")\n ... return object.__getattribute__(*args)\n ...\n >>> c = C()\n >>> c.__len__() # Explicit lookup via instance\n Class getattribute invoked\n 10\n >>> type(c).__len__(c) # Explicit lookup via type\n Metaclass getattribute invoked\n 10\n >>> len(c) # Implicit lookup\n 10\n\nBypassing the "__getattribute__()" machinery in this fashion provides\nsignificant scope for speed optimisations within the interpreter, at\nthe cost of some flexibility in the handling of special methods (the\nspecial method *must* be set on the class object itself in order to be\nconsistently invoked by the interpreter).\n\n-[ Footnotes ]-\n\n[1] It *is* possible in some cases to change an object\'s type, under\n certain controlled conditions. It generally isn\'t a good idea\n though, since it can lead to some very strange behaviour if it is\n handled incorrectly.\n\n[2] For operands of the same type, it is assumed that if the non-\n reflected method (such as "__add__()") fails the operation is not\n supported, which is why the reflected method is not called.\n', - 'string-methods': '\nString Methods\n**************\n\nStrings implement all of the *common* sequence operations, along with\nthe additional methods described below.\n\nStrings also support two styles of string formatting, one providing a\nlarge degree of flexibility and customization (see "str.format()",\n*Format String Syntax* and *String Formatting*) and the other based on\nC "printf" style formatting that handles a narrower range of types and\nis slightly harder to use correctly, but is often faster for the cases\nit can handle (*printf-style String Formatting*).\n\nThe *Text Processing Services* section of the standard library covers\na number of other modules that provide various text related utilities\n(including regular expression support in the "re" module).\n\nstr.capitalize()\n\n Return a copy of the string with its first character capitalized\n and the rest lowercased.\n\nstr.casefold()\n\n Return a casefolded copy of the string. Casefolded strings may be\n used for caseless matching.\n\n Casefolding is similar to lowercasing but more aggressive because\n it is intended to remove all case distinctions in a string. For\n example, the German lowercase letter "\'\xc3\x9f\'" is equivalent to ""ss"".\n Since it is already lowercase, "lower()" would do nothing to "\'\xc3\x9f\'";\n "casefold()" converts it to ""ss"".\n\n The casefolding algorithm is described in section 3.13 of the\n Unicode Standard.\n\n New in version 3.3.\n\nstr.center(width[, fillchar])\n\n Return centered in a string of length *width*. Padding is done\n using the specified *fillchar* (default is a space).\n\nstr.count(sub[, start[, end]])\n\n Return the number of non-overlapping occurrences of substring *sub*\n in the range [*start*, *end*]. Optional arguments *start* and\n *end* are interpreted as in slice notation.\n\nstr.encode(encoding="utf-8", errors="strict")\n\n Return an encoded version of the string as a bytes object. Default\n encoding is "\'utf-8\'". *errors* may be given to set a different\n error handling scheme. The default for *errors* is "\'strict\'",\n meaning that encoding errors raise a "UnicodeError". Other possible\n values are "\'ignore\'", "\'replace\'", "\'xmlcharrefreplace\'",\n "\'backslashreplace\'" and any other name registered via\n "codecs.register_error()", see section *Codec Base Classes*. For a\n list of possible encodings, see section *Standard Encodings*.\n\n Changed in version 3.1: Support for keyword arguments added.\n\nstr.endswith(suffix[, start[, end]])\n\n Return "True" if the string ends with the specified *suffix*,\n otherwise return "False". *suffix* can also be a tuple of suffixes\n to look for. With optional *start*, test beginning at that\n position. With optional *end*, stop comparing at that position.\n\nstr.expandtabs(tabsize=8)\n\n Return a copy of the string where all tab characters are replaced\n by one or more spaces, depending on the current column and the\n given tab size. Tab positions occur every *tabsize* characters\n (default is 8, giving tab positions at columns 0, 8, 16 and so on).\n To expand the string, the current column is set to zero and the\n string is examined character by character. If the character is a\n tab ("\\t"), one or more space characters are inserted in the result\n until the current column is equal to the next tab position. (The\n tab character itself is not copied.) If the character is a newline\n ("\\n") or return ("\\r"), it is copied and the current column is\n reset to zero. Any other character is copied unchanged and the\n current column is incremented by one regardless of how the\n character is represented when printed.\n\n >>> \'01\\t012\\t0123\\t01234\'.expandtabs()\n \'01 012 0123 01234\'\n >>> \'01\\t012\\t0123\\t01234\'.expandtabs(4)\n \'01 012 0123 01234\'\n\nstr.find(sub[, start[, end]])\n\n Return the lowest index in the string where substring *sub* is\n found, such that *sub* is contained in the slice "s[start:end]".\n Optional arguments *start* and *end* are interpreted as in slice\n notation. Return "-1" if *sub* is not found.\n\n Note: The "find()" method should be used only if you need to know the\n position of *sub*. To check if *sub* is a substring or not, use\n the "in" operator:\n\n >>> \'Py\' in \'Python\'\n True\n\nstr.format(*args, **kwargs)\n\n Perform a string formatting operation. The string on which this\n method is called can contain literal text or replacement fields\n delimited by braces "{}". Each replacement field contains either\n the numeric index of a positional argument, or the name of a\n keyword argument. Returns a copy of the string where each\n replacement field is replaced with the string value of the\n corresponding argument.\n\n >>> "The sum of 1 + 2 is {0}".format(1+2)\n \'The sum of 1 + 2 is 3\'\n\n See *Format String Syntax* for a description of the various\n formatting options that can be specified in format strings.\n\nstr.format_map(mapping)\n\n Similar to "str.format(**mapping)", except that "mapping" is used\n directly and not copied to a "dict". This is useful if for example\n "mapping" is a dict subclass:\n\n >>> class Default(dict):\n ... def __missing__(self, key):\n ... return key\n ...\n >>> \'{name} was born in {country}\'.format_map(Default(name=\'Guido\'))\n \'Guido was born in country\'\n\n New in version 3.2.\n\nstr.index(sub[, start[, end]])\n\n Like "find()", but raise "ValueError" when the substring is not\n found.\n\nstr.isalnum()\n\n Return true if all characters in the string are alphanumeric and\n there is at least one character, false otherwise. A character "c"\n is alphanumeric if one of the following returns "True":\n "c.isalpha()", "c.isdecimal()", "c.isdigit()", or "c.isnumeric()".\n\nstr.isalpha()\n\n Return true if all characters in the string are alphabetic and\n there is at least one character, false otherwise. Alphabetic\n characters are those characters defined in the Unicode character\n database as "Letter", i.e., those with general category property\n being one of "Lm", "Lt", "Lu", "Ll", or "Lo". Note that this is\n different from the "Alphabetic" property defined in the Unicode\n Standard.\n\nstr.isdecimal()\n\n Return true if all characters in the string are decimal characters\n and there is at least one character, false otherwise. Decimal\n characters are those from general category "Nd". This category\n includes digit characters, and all characters that can be used to\n form decimal-radix numbers, e.g. U+0660, ARABIC-INDIC DIGIT ZERO.\n\nstr.isdigit()\n\n Return true if all characters in the string are digits and there is\n at least one character, false otherwise. Digits include decimal\n characters and digits that need special handling, such as the\n compatibility superscript digits. Formally, a digit is a character\n that has the property value Numeric_Type=Digit or\n Numeric_Type=Decimal.\n\nstr.isidentifier()\n\n Return true if the string is a valid identifier according to the\n language definition, section *Identifiers and keywords*.\n\n Use "keyword.iskeyword()" to test for reserved identifiers such as\n "def" and "class".\n\nstr.islower()\n\n Return true if all cased characters [4] in the string are lowercase\n and there is at least one cased character, false otherwise.\n\nstr.isnumeric()\n\n Return true if all characters in the string are numeric characters,\n and there is at least one character, false otherwise. Numeric\n characters include digit characters, and all characters that have\n the Unicode numeric value property, e.g. U+2155, VULGAR FRACTION\n ONE FIFTH. Formally, numeric characters are those with the\n property value Numeric_Type=Digit, Numeric_Type=Decimal or\n Numeric_Type=Numeric.\n\nstr.isprintable()\n\n Return true if all characters in the string are printable or the\n string is empty, false otherwise. Nonprintable characters are\n those characters defined in the Unicode character database as\n "Other" or "Separator", excepting the ASCII space (0x20) which is\n considered printable. (Note that printable characters in this\n context are those which should not be escaped when "repr()" is\n invoked on a string. It has no bearing on the handling of strings\n written to "sys.stdout" or "sys.stderr".)\n\nstr.isspace()\n\n Return true if there are only whitespace characters in the string\n and there is at least one character, false otherwise. Whitespace\n characters are those characters defined in the Unicode character\n database as "Other" or "Separator" and those with bidirectional\n property being one of "WS", "B", or "S".\n\nstr.istitle()\n\n Return true if the string is a titlecased string and there is at\n least one character, for example uppercase characters may only\n follow uncased characters and lowercase characters only cased ones.\n Return false otherwise.\n\nstr.isupper()\n\n Return true if all cased characters [4] in the string are uppercase\n and there is at least one cased character, false otherwise.\n\nstr.join(iterable)\n\n Return a string which is the concatenation of the strings in the\n *iterable* *iterable*. A "TypeError" will be raised if there are\n any non-string values in *iterable*, including "bytes" objects.\n The separator between elements is the string providing this method.\n\nstr.ljust(width[, fillchar])\n\n Return the string left justified in a string of length *width*.\n Padding is done using the specified *fillchar* (default is a\n space). The original string is returned if *width* is less than or\n equal to "len(s)".\n\nstr.lower()\n\n Return a copy of the string with all the cased characters [4]\n converted to lowercase.\n\n The lowercasing algorithm used is described in section 3.13 of the\n Unicode Standard.\n\nstr.lstrip([chars])\n\n Return a copy of the string with leading characters removed. The\n *chars* argument is a string specifying the set of characters to be\n removed. If omitted or "None", the *chars* argument defaults to\n removing whitespace. The *chars* argument is not a prefix; rather,\n all combinations of its values are stripped:\n\n >>> \' spacious \'.lstrip()\n \'spacious \'\n >>> \'www.example.com\'.lstrip(\'cmowz.\')\n \'example.com\'\n\nstatic str.maketrans(x[, y[, z]])\n\n This static method returns a translation table usable for\n "str.translate()".\n\n If there is only one argument, it must be a dictionary mapping\n Unicode ordinals (integers) or characters (strings of length 1) to\n Unicode ordinals, strings (of arbitrary lengths) or None.\n Character keys will then be converted to ordinals.\n\n If there are two arguments, they must be strings of equal length,\n and in the resulting dictionary, each character in x will be mapped\n to the character at the same position in y. If there is a third\n argument, it must be a string, whose characters will be mapped to\n None in the result.\n\nstr.partition(sep)\n\n Split the string at the first occurrence of *sep*, and return a\n 3-tuple containing the part before the separator, the separator\n itself, and the part after the separator. If the separator is not\n found, return a 3-tuple containing the string itself, followed by\n two empty strings.\n\nstr.replace(old, new[, count])\n\n Return a copy of the string with all occurrences of substring *old*\n replaced by *new*. If the optional argument *count* is given, only\n the first *count* occurrences are replaced.\n\nstr.rfind(sub[, start[, end]])\n\n Return the highest index in the string where substring *sub* is\n found, such that *sub* is contained within "s[start:end]".\n Optional arguments *start* and *end* are interpreted as in slice\n notation. Return "-1" on failure.\n\nstr.rindex(sub[, start[, end]])\n\n Like "rfind()" but raises "ValueError" when the substring *sub* is\n not found.\n\nstr.rjust(width[, fillchar])\n\n Return the string right justified in a string of length *width*.\n Padding is done using the specified *fillchar* (default is a\n space). The original string is returned if *width* is less than or\n equal to "len(s)".\n\nstr.rpartition(sep)\n\n Split the string at the last occurrence of *sep*, and return a\n 3-tuple containing the part before the separator, the separator\n itself, and the part after the separator. If the separator is not\n found, return a 3-tuple containing two empty strings, followed by\n the string itself.\n\nstr.rsplit(sep=None, maxsplit=-1)\n\n Return a list of the words in the string, using *sep* as the\n delimiter string. If *maxsplit* is given, at most *maxsplit* splits\n are done, the *rightmost* ones. If *sep* is not specified or\n "None", any whitespace string is a separator. Except for splitting\n from the right, "rsplit()" behaves like "split()" which is\n described in detail below.\n\nstr.rstrip([chars])\n\n Return a copy of the string with trailing characters removed. The\n *chars* argument is a string specifying the set of characters to be\n removed. If omitted or "None", the *chars* argument defaults to\n removing whitespace. The *chars* argument is not a suffix; rather,\n all combinations of its values are stripped:\n\n >>> \' spacious \'.rstrip()\n \' spacious\'\n >>> \'mississippi\'.rstrip(\'ipz\')\n \'mississ\'\n\nstr.split(sep=None, maxsplit=-1)\n\n Return a list of the words in the string, using *sep* as the\n delimiter string. If *maxsplit* is given, at most *maxsplit*\n splits are done (thus, the list will have at most "maxsplit+1"\n elements). If *maxsplit* is not specified or "-1", then there is\n no limit on the number of splits (all possible splits are made).\n\n If *sep* is given, consecutive delimiters are not grouped together\n and are deemed to delimit empty strings (for example,\n "\'1,,2\'.split(\',\')" returns "[\'1\', \'\', \'2\']"). The *sep* argument\n may consist of multiple characters (for example,\n "\'1<>2<>3\'.split(\'<>\')" returns "[\'1\', \'2\', \'3\']"). Splitting an\n empty string with a specified separator returns "[\'\']".\n\n If *sep* is not specified or is "None", a different splitting\n algorithm is applied: runs of consecutive whitespace are regarded\n as a single separator, and the result will contain no empty strings\n at the start or end if the string has leading or trailing\n whitespace. Consequently, splitting an empty string or a string\n consisting of just whitespace with a "None" separator returns "[]".\n\n For example, "\' 1 2 3 \'.split()" returns "[\'1\', \'2\', \'3\']", and\n "\' 1 2 3 \'.split(None, 1)" returns "[\'1\', \'2 3 \']".\n\nstr.splitlines([keepends])\n\n Return a list of the lines in the string, breaking at line\n boundaries. This method uses the *universal newlines* approach to\n splitting lines. Line breaks are not included in the resulting list\n unless *keepends* is given and true.\n\n For example, "\'ab c\\n\\nde fg\\rkl\\r\\n\'.splitlines()" returns "[\'ab\n c\', \'\', \'de fg\', \'kl\']", while the same call with\n "splitlines(True)" returns "[\'ab c\\n\', \'\\n\', \'de fg\\r\', \'kl\\r\\n\']".\n\n Unlike "split()" when a delimiter string *sep* is given, this\n method returns an empty list for the empty string, and a terminal\n line break does not result in an extra line.\n\nstr.startswith(prefix[, start[, end]])\n\n Return "True" if string starts with the *prefix*, otherwise return\n "False". *prefix* can also be a tuple of prefixes to look for.\n With optional *start*, test string beginning at that position.\n With optional *end*, stop comparing string at that position.\n\nstr.strip([chars])\n\n Return a copy of the string with the leading and trailing\n characters removed. The *chars* argument is a string specifying the\n set of characters to be removed. If omitted or "None", the *chars*\n argument defaults to removing whitespace. The *chars* argument is\n not a prefix or suffix; rather, all combinations of its values are\n stripped:\n\n >>> \' spacious \'.strip()\n \'spacious\'\n >>> \'www.example.com\'.strip(\'cmowz.\')\n \'example\'\n\nstr.swapcase()\n\n Return a copy of the string with uppercase characters converted to\n lowercase and vice versa. Note that it is not necessarily true that\n "s.swapcase().swapcase() == s".\n\nstr.title()\n\n Return a titlecased version of the string where words start with an\n uppercase character and the remaining characters are lowercase.\n\n The algorithm uses a simple language-independent definition of a\n word as groups of consecutive letters. The definition works in\n many contexts but it means that apostrophes in contractions and\n possessives form word boundaries, which may not be the desired\n result:\n\n >>> "they\'re bill\'s friends from the UK".title()\n "They\'Re Bill\'S Friends From The Uk"\n\n A workaround for apostrophes can be constructed using regular\n expressions:\n\n >>> import re\n >>> def titlecase(s):\n ... return re.sub(r"[A-Za-z]+(\'[A-Za-z]+)?",\n ... lambda mo: mo.group(0)[0].upper() +\n ... mo.group(0)[1:].lower(),\n ... s)\n ...\n >>> titlecase("they\'re bill\'s friends.")\n "They\'re Bill\'s Friends."\n\nstr.translate(map)\n\n Return a copy of the *s* where all characters have been mapped\n through the *map* which must be a dictionary of Unicode ordinals\n (integers) to Unicode ordinals, strings or "None". Unmapped\n characters are left untouched. Characters mapped to "None" are\n deleted.\n\n You can use "str.maketrans()" to create a translation map from\n character-to-character mappings in different formats.\n\n Note: An even more flexible approach is to create a custom character\n mapping codec using the "codecs" module (see "encodings.cp1251"\n for an example).\n\nstr.upper()\n\n Return a copy of the string with all the cased characters [4]\n converted to uppercase. Note that "str.upper().isupper()" might be\n "False" if "s" contains uncased characters or if the Unicode\n category of the resulting character(s) is not "Lu" (Letter,\n uppercase), but e.g. "Lt" (Letter, titlecase).\n\n The uppercasing algorithm used is described in section 3.13 of the\n Unicode Standard.\n\nstr.zfill(width)\n\n Return the numeric string left filled with zeros in a string of\n length *width*. A sign prefix is handled correctly. The original\n string is returned if *width* is less than or equal to "len(s)".\n', - 'strings': '\nString and Bytes literals\n*************************\n\nString literals are described by the following lexical definitions:\n\n stringliteral ::= [stringprefix](shortstring | longstring)\n stringprefix ::= "r" | "u" | "R" | "U"\n shortstring ::= "\'" shortstringitem* "\'" | \'"\' shortstringitem* \'"\'\n longstring ::= "\'\'\'" longstringitem* "\'\'\'" | \'"""\' longstringitem* \'"""\'\n shortstringitem ::= shortstringchar | stringescapeseq\n longstringitem ::= longstringchar | stringescapeseq\n shortstringchar ::= <any source character except "\\" or newline or the quote>\n longstringchar ::= <any source character except "\\">\n stringescapeseq ::= "\\" <any source character>\n\n bytesliteral ::= bytesprefix(shortbytes | longbytes)\n bytesprefix ::= "b" | "B" | "br" | "Br" | "bR" | "BR" | "rb" | "rB" | "Rb" | "RB"\n shortbytes ::= "\'" shortbytesitem* "\'" | \'"\' shortbytesitem* \'"\'\n longbytes ::= "\'\'\'" longbytesitem* "\'\'\'" | \'"""\' longbytesitem* \'"""\'\n shortbytesitem ::= shortbyteschar | bytesescapeseq\n longbytesitem ::= longbyteschar | bytesescapeseq\n shortbyteschar ::= <any ASCII character except "\\" or newline or the quote>\n longbyteschar ::= <any ASCII character except "\\">\n bytesescapeseq ::= "\\" <any ASCII character>\n\nOne syntactic restriction not indicated by these productions is that\nwhitespace is not allowed between the "stringprefix" or "bytesprefix"\nand the rest of the literal. The source character set is defined by\nthe encoding declaration; it is UTF-8 if no encoding declaration is\ngiven in the source file; see section *Encoding declarations*.\n\nIn plain English: Both types of literals can be enclosed in matching\nsingle quotes ("\'") or double quotes ("""). They can also be enclosed\nin matching groups of three single or double quotes (these are\ngenerally referred to as *triple-quoted strings*). The backslash\n("\\") character is used to escape characters that otherwise have a\nspecial meaning, such as newline, backslash itself, or the quote\ncharacter.\n\nBytes literals are always prefixed with "\'b\'" or "\'B\'"; they produce\nan instance of the "bytes" type instead of the "str" type. They may\nonly contain ASCII characters; bytes with a numeric value of 128 or\ngreater must be expressed with escapes.\n\nAs of Python 3.3 it is possible again to prefix unicode strings with a\n"u" prefix to simplify maintenance of dual 2.x and 3.x codebases.\n\nBoth string and bytes literals may optionally be prefixed with a\nletter "\'r\'" or "\'R\'"; such strings are called *raw strings* and treat\nbackslashes as literal characters. As a result, in string literals,\n"\'\\U\'" and "\'\\u\'" escapes in raw strings are not treated specially.\nGiven that Python 2.x\'s raw unicode literals behave differently than\nPython 3.x\'s the "\'ur\'" syntax is not supported.\n\n New in version 3.3: The "\'rb\'" prefix of raw bytes literals has\n been added as a synonym of "\'br\'".\n\n New in version 3.3: Support for the unicode legacy literal\n ("u\'value\'") was reintroduced to simplify the maintenance of dual\n Python 2.x and 3.x codebases. See **PEP 414** for more information.\n\nIn triple-quoted strings, unescaped newlines and quotes are allowed\n(and are retained), except that three unescaped quotes in a row\nterminate the string. (A "quote" is the character used to open the\nstring, i.e. either "\'" or """.)\n\nUnless an "\'r\'" or "\'R\'" prefix is present, escape sequences in\nstrings are interpreted according to rules similar to those used by\nStandard C. The recognized escape sequences are:\n\n+-------------------+-----------------------------------+---------+\n| Escape Sequence | Meaning | Notes |\n+===================+===================================+=========+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n| "\\ooo" | Character with octal value *ooo* | (1,3) |\n+-------------------+-----------------------------------+---------+\n| "\\xhh" | Character with hex value *hh* | (2,3) |\n+-------------------+-----------------------------------+---------+\n\nEscape sequences only recognized in string literals are:\n\n+-------------------+-----------------------------------+---------+\n| Escape Sequence | Meaning | Notes |\n+===================+===================================+=========+\n| "\\N{name}" | Character named *name* in the | (4) |\n+-------------------+-----------------------------------+---------+\n| "\\uxxxx" | Character with 16-bit hex value | (5) |\n+-------------------+-----------------------------------+---------+\n| "\\Uxxxxxxxx" | Character with 32-bit hex value | (6) |\n+-------------------+-----------------------------------+---------+\n\nNotes:\n\n1. As in Standard C, up to three octal digits are accepted.\n\n2. Unlike in Standard C, exactly two hex digits are required.\n\n3. In a bytes literal, hexadecimal and octal escapes denote the byte\n with the given value. In a string literal, these escapes denote a\n Unicode character with the given value.\n\n4. Changed in version 3.3: Support for name aliases [1] has been\n added.\n\n5. Individual code units which form parts of a surrogate pair can be\n encoded using this escape sequence. Exactly four hex digits are\n required.\n\n6. Any Unicode character can be encoded this way. Exactly eight hex\n digits are required.\n\nUnlike Standard C, all unrecognized escape sequences are left in the\nstring unchanged, i.e., *the backslash is left in the string*. (This\nbehavior is useful when debugging: if an escape sequence is mistyped,\nthe resulting output is more easily recognized as broken.) It is also\nimportant to note that the escape sequences only recognized in string\nliterals fall into the category of unrecognized escapes for bytes\nliterals.\n\nEven in a raw string, string quotes can be escaped with a backslash,\nbut the backslash remains in the string; for example, "r"\\""" is a\nvalid string literal consisting of two characters: a backslash and a\ndouble quote; "r"\\"" is not a valid string literal (even a raw string\ncannot end in an odd number of backslashes). Specifically, *a raw\nstring cannot end in a single backslash* (since the backslash would\nescape the following quote character). Note also that a single\nbackslash followed by a newline is interpreted as those two characters\nas part of the string, *not* as a line continuation.\n', + 'specialattrs': '\nSpecial Attributes\n******************\n\nThe implementation adds a few special read-only attributes to several\nobject types, where they are relevant. Some of these are not reported\nby the "dir()" built-in function.\n\nobject.__dict__\n\n A dictionary or other mapping object used to store an object\'s\n (writable) attributes.\n\ninstance.__class__\n\n The class to which a class instance belongs.\n\nclass.__bases__\n\n The tuple of base classes of a class object.\n\nclass.__name__\n\n The name of the class or type.\n\nclass.__qualname__\n\n The *qualified name* of the class or type.\n\n New in version 3.3.\n\nclass.__mro__\n\n This attribute is a tuple of classes that are considered when\n looking for base classes during method resolution.\n\nclass.mro()\n\n This method can be overridden by a metaclass to customize the\n method resolution order for its instances. It is called at class\n instantiation, and its result is stored in "__mro__".\n\nclass.__subclasses__()\n\n Each class keeps a list of weak references to its immediate\n subclasses. This method returns a list of all those references\n still alive. Example:\n\n >>> int.__subclasses__()\n [<class \'bool\'>]\n\n-[ Footnotes ]-\n\n[1] Additional information on these special methods may be found\n in the Python Reference Manual (*Basic customization*).\n\n[2] As a consequence, the list "[1, 2]" is considered equal to\n "[1.0, 2.0]", and similarly for tuples.\n\n[3] They must have since the parser can\'t tell the type of the\n operands.\n\n[4] Cased characters are those with general category property\n being one of "Lu" (Letter, uppercase), "Ll" (Letter, lowercase),\n or "Lt" (Letter, titlecase).\n\n[5] To format only a tuple you should therefore provide a\n singleton tuple whose only element is the tuple to be formatted.\n', + 'specialnames': '\nSpecial method names\n********************\n\nA class can implement certain operations that are invoked by special\nsyntax (such as arithmetic operations or subscripting and slicing) by\ndefining methods with special names. This is Python\'s approach to\n*operator overloading*, allowing classes to define their own behavior\nwith respect to language operators. For instance, if a class defines\na method named "__getitem__()", and "x" is an instance of this class,\nthen "x[i]" is roughly equivalent to "type(x).__getitem__(x, i)".\nExcept where mentioned, attempts to execute an operation raise an\nexception when no appropriate method is defined (typically\n"AttributeError" or "TypeError").\n\nWhen implementing a class that emulates any built-in type, it is\nimportant that the emulation only be implemented to the degree that it\nmakes sense for the object being modelled. For example, some\nsequences may work well with retrieval of individual elements, but\nextracting a slice may not make sense. (One example of this is the\n"NodeList" interface in the W3C\'s Document Object Model.)\n\n\nBasic customization\n===================\n\nobject.__new__(cls[, ...])\n\n Called to create a new instance of class *cls*. "__new__()" is a\n static method (special-cased so you need not declare it as such)\n that takes the class of which an instance was requested as its\n first argument. The remaining arguments are those passed to the\n object constructor expression (the call to the class). The return\n value of "__new__()" should be the new object instance (usually an\n instance of *cls*).\n\n Typical implementations create a new instance of the class by\n invoking the superclass\'s "__new__()" method using\n "super(currentclass, cls).__new__(cls[, ...])" with appropriate\n arguments and then modifying the newly-created instance as\n necessary before returning it.\n\n If "__new__()" returns an instance of *cls*, then the new\n instance\'s "__init__()" method will be invoked like\n "__init__(self[, ...])", where *self* is the new instance and the\n remaining arguments are the same as were passed to "__new__()".\n\n If "__new__()" does not return an instance of *cls*, then the new\n instance\'s "__init__()" method will not be invoked.\n\n "__new__()" is intended mainly to allow subclasses of immutable\n types (like int, str, or tuple) to customize instance creation. It\n is also commonly overridden in custom metaclasses in order to\n customize class creation.\n\nobject.__init__(self[, ...])\n\n Called when the instance is created. The arguments are those\n passed to the class constructor expression. If a base class has an\n "__init__()" method, the derived class\'s "__init__()" method, if\n any, must explicitly call it to ensure proper initialization of the\n base class part of the instance; for example:\n "BaseClass.__init__(self, [args...])". As a special constraint on\n constructors, no value may be returned; doing so will cause a\n "TypeError" to be raised at runtime.\n\nobject.__del__(self)\n\n Called when the instance is about to be destroyed. This is also\n called a destructor. If a base class has a "__del__()" method, the\n derived class\'s "__del__()" method, if any, must explicitly call it\n to ensure proper deletion of the base class part of the instance.\n Note that it is possible (though not recommended!) for the\n "__del__()" method to postpone destruction of the instance by\n creating a new reference to it. It may then be called at a later\n time when this new reference is deleted. It is not guaranteed that\n "__del__()" methods are called for objects that still exist when\n the interpreter exits.\n\n Note: "del x" doesn\'t directly call "x.__del__()" --- the former\n decrements the reference count for "x" by one, and the latter is\n only called when "x"\'s reference count reaches zero. Some common\n situations that may prevent the reference count of an object from\n going to zero include: circular references between objects (e.g.,\n a doubly-linked list or a tree data structure with parent and\n child pointers); a reference to the object on the stack frame of\n a function that caught an exception (the traceback stored in\n "sys.exc_info()[2]" keeps the stack frame alive); or a reference\n to the object on the stack frame that raised an unhandled\n exception in interactive mode (the traceback stored in\n "sys.last_traceback" keeps the stack frame alive). The first\n situation can only be remedied by explicitly breaking the cycles;\n the latter two situations can be resolved by storing "None" in\n "sys.last_traceback". Circular references which are garbage are\n detected and cleaned up when the cyclic garbage collector is\n enabled (it\'s on by default). Refer to the documentation for the\n "gc" module for more information about this topic.\n\n Warning: Due to the precarious circumstances under which\n "__del__()" methods are invoked, exceptions that occur during\n their execution are ignored, and a warning is printed to\n "sys.stderr" instead. Also, when "__del__()" is invoked in\n response to a module being deleted (e.g., when execution of the\n program is done), other globals referenced by the "__del__()"\n method may already have been deleted or in the process of being\n torn down (e.g. the import machinery shutting down). For this\n reason, "__del__()" methods should do the absolute minimum needed\n to maintain external invariants. Starting with version 1.5,\n Python guarantees that globals whose name begins with a single\n underscore are deleted from their module before other globals are\n deleted; if no other references to such globals exist, this may\n help in assuring that imported modules are still available at the\n time when the "__del__()" method is called.\n\nobject.__repr__(self)\n\n Called by the "repr()" built-in function to compute the "official"\n string representation of an object. If at all possible, this\n should look like a valid Python expression that could be used to\n recreate an object with the same value (given an appropriate\n environment). If this is not possible, a string of the form\n "<...some useful description...>" should be returned. The return\n value must be a string object. If a class defines "__repr__()" but\n not "__str__()", then "__repr__()" is also used when an "informal"\n string representation of instances of that class is required.\n\n This is typically used for debugging, so it is important that the\n representation is information-rich and unambiguous.\n\nobject.__str__(self)\n\n Called by "str(object)" and the built-in functions "format()" and\n "print()" to compute the "informal" or nicely printable string\n representation of an object. The return value must be a *string*\n object.\n\n This method differs from "object.__repr__()" in that there is no\n expectation that "__str__()" return a valid Python expression: a\n more convenient or concise representation can be used.\n\n The default implementation defined by the built-in type "object"\n calls "object.__repr__()".\n\nobject.__bytes__(self)\n\n Called by "bytes()" to compute a byte-string representation of an\n object. This should return a "bytes" object.\n\nobject.__format__(self, format_spec)\n\n Called by the "format()" built-in function (and by extension, the\n "str.format()" method of class "str") to produce a "formatted"\n string representation of an object. The "format_spec" argument is a\n string that contains a description of the formatting options\n desired. The interpretation of the "format_spec" argument is up to\n the type implementing "__format__()", however most classes will\n either delegate formatting to one of the built-in types, or use a\n similar formatting option syntax.\n\n See *Format Specification Mini-Language* for a description of the\n standard formatting syntax.\n\n The return value must be a string object.\n\nobject.__lt__(self, other)\nobject.__le__(self, other)\nobject.__eq__(self, other)\nobject.__ne__(self, other)\nobject.__gt__(self, other)\nobject.__ge__(self, other)\n\n These are the so-called "rich comparison" methods. The\n correspondence between operator symbols and method names is as\n follows: "x<y" calls "x.__lt__(y)", "x<=y" calls "x.__le__(y)",\n "x==y" calls "x.__eq__(y)", "x!=y" calls "x.__ne__(y)", "x>y" calls\n "x.__gt__(y)", and "x>=y" calls "x.__ge__(y)".\n\n A rich comparison method may return the singleton "NotImplemented"\n if it does not implement the operation for a given pair of\n arguments. By convention, "False" and "True" are returned for a\n successful comparison. However, these methods can return any value,\n so if the comparison operator is used in a Boolean context (e.g.,\n in the condition of an "if" statement), Python will call "bool()"\n on the value to determine if the result is true or false.\n\n There are no implied relationships among the comparison operators.\n The truth of "x==y" does not imply that "x!=y" is false.\n Accordingly, when defining "__eq__()", one should also define\n "__ne__()" so that the operators will behave as expected. See the\n paragraph on "__hash__()" for some important notes on creating\n *hashable* objects which support custom comparison operations and\n are usable as dictionary keys.\n\n There are no swapped-argument versions of these methods (to be used\n when the left argument does not support the operation but the right\n argument does); rather, "__lt__()" and "__gt__()" are each other\'s\n reflection, "__le__()" and "__ge__()" are each other\'s reflection,\n and "__eq__()" and "__ne__()" are their own reflection.\n\n Arguments to rich comparison methods are never coerced.\n\n To automatically generate ordering operations from a single root\n operation, see "functools.total_ordering()".\n\nobject.__hash__(self)\n\n Called by built-in function "hash()" and for operations on members\n of hashed collections including "set", "frozenset", and "dict".\n "__hash__()" should return an integer. The only required property\n is that objects which compare equal have the same hash value; it is\n advised to somehow mix together (e.g. using exclusive or) the hash\n values for the components of the object that also play a part in\n comparison of objects.\n\n Note: "hash()" truncates the value returned from an object\'s\n custom "__hash__()" method to the size of a "Py_ssize_t". This\n is typically 8 bytes on 64-bit builds and 4 bytes on 32-bit\n builds. If an object\'s "__hash__()" must interoperate on builds\n of different bit sizes, be sure to check the width on all\n supported builds. An easy way to do this is with "python -c\n "import sys; print(sys.hash_info.width)""\n\n If a class does not define an "__eq__()" method it should not\n define a "__hash__()" operation either; if it defines "__eq__()"\n but not "__hash__()", its instances will not be usable as items in\n hashable collections. If a class defines mutable objects and\n implements an "__eq__()" method, it should not implement\n "__hash__()", since the implementation of hashable collections\n requires that a key\'s hash value is immutable (if the object\'s hash\n value changes, it will be in the wrong hash bucket).\n\n User-defined classes have "__eq__()" and "__hash__()" methods by\n default; with them, all objects compare unequal (except with\n themselves) and "x.__hash__()" returns an appropriate value such\n that "x == y" implies both that "x is y" and "hash(x) == hash(y)".\n\n A class that overrides "__eq__()" and does not define "__hash__()"\n will have its "__hash__()" implicitly set to "None". When the\n "__hash__()" method of a class is "None", instances of the class\n will raise an appropriate "TypeError" when a program attempts to\n retrieve their hash value, and will also be correctly identified as\n unhashable when checking "isinstance(obj, collections.Hashable").\n\n If a class that overrides "__eq__()" needs to retain the\n implementation of "__hash__()" from a parent class, the interpreter\n must be told this explicitly by setting "__hash__ =\n <ParentClass>.__hash__".\n\n If a class that does not override "__eq__()" wishes to suppress\n hash support, it should include "__hash__ = None" in the class\n definition. A class which defines its own "__hash__()" that\n explicitly raises a "TypeError" would be incorrectly identified as\n hashable by an "isinstance(obj, collections.Hashable)" call.\n\n Note: By default, the "__hash__()" values of str, bytes and\n datetime objects are "salted" with an unpredictable random value.\n Although they remain constant within an individual Python\n process, they are not predictable between repeated invocations of\n Python.This is intended to provide protection against a denial-\n of-service caused by carefully-chosen inputs that exploit the\n worst case performance of a dict insertion, O(n^2) complexity.\n See http://www.ocert.org/advisories/ocert-2011-003.html for\n details.Changing hash values affects the iteration order of\n dicts, sets and other mappings. Python has never made guarantees\n about this ordering (and it typically varies between 32-bit and\n 64-bit builds).See also "PYTHONHASHSEED".\n\n Changed in version 3.3: Hash randomization is enabled by default.\n\nobject.__bool__(self)\n\n Called to implement truth value testing and the built-in operation\n "bool()"; should return "False" or "True". When this method is not\n defined, "__len__()" is called, if it is defined, and the object is\n considered true if its result is nonzero. If a class defines\n neither "__len__()" nor "__bool__()", all its instances are\n considered true.\n\n\nCustomizing attribute access\n============================\n\nThe following methods can be defined to customize the meaning of\nattribute access (use of, assignment to, or deletion of "x.name") for\nclass instances.\n\nobject.__getattr__(self, name)\n\n Called when an attribute lookup has not found the attribute in the\n usual places (i.e. it is not an instance attribute nor is it found\n in the class tree for "self"). "name" is the attribute name. This\n method should return the (computed) attribute value or raise an\n "AttributeError" exception.\n\n Note that if the attribute is found through the normal mechanism,\n "__getattr__()" is not called. (This is an intentional asymmetry\n between "__getattr__()" and "__setattr__()".) This is done both for\n efficiency reasons and because otherwise "__getattr__()" would have\n no way to access other attributes of the instance. Note that at\n least for instance variables, you can fake total control by not\n inserting any values in the instance attribute dictionary (but\n instead inserting them in another object). See the\n "__getattribute__()" method below for a way to actually get total\n control over attribute access.\n\nobject.__getattribute__(self, name)\n\n Called unconditionally to implement attribute accesses for\n instances of the class. If the class also defines "__getattr__()",\n the latter will not be called unless "__getattribute__()" either\n calls it explicitly or raises an "AttributeError". This method\n should return the (computed) attribute value or raise an\n "AttributeError" exception. In order to avoid infinite recursion in\n this method, its implementation should always call the base class\n method with the same name to access any attributes it needs, for\n example, "object.__getattribute__(self, name)".\n\n Note: This method may still be bypassed when looking up special\n methods as the result of implicit invocation via language syntax\n or built-in functions. See *Special method lookup*.\n\nobject.__setattr__(self, name, value)\n\n Called when an attribute assignment is attempted. This is called\n instead of the normal mechanism (i.e. store the value in the\n instance dictionary). *name* is the attribute name, *value* is the\n value to be assigned to it.\n\n If "__setattr__()" wants to assign to an instance attribute, it\n should call the base class method with the same name, for example,\n "object.__setattr__(self, name, value)".\n\nobject.__delattr__(self, name)\n\n Like "__setattr__()" but for attribute deletion instead of\n assignment. This should only be implemented if "del obj.name" is\n meaningful for the object.\n\nobject.__dir__(self)\n\n Called when "dir()" is called on the object. A sequence must be\n returned. "dir()" converts the returned sequence to a list and\n sorts it.\n\n\nImplementing Descriptors\n------------------------\n\nThe following methods only apply when an instance of the class\ncontaining the method (a so-called *descriptor* class) appears in an\n*owner* class (the descriptor must be in either the owner\'s class\ndictionary or in the class dictionary for one of its parents). In the\nexamples below, "the attribute" refers to the attribute whose name is\nthe key of the property in the owner class\' "__dict__".\n\nobject.__get__(self, instance, owner)\n\n Called to get the attribute of the owner class (class attribute\n access) or of an instance of that class (instance attribute\n access). *owner* is always the owner class, while *instance* is the\n instance that the attribute was accessed through, or "None" when\n the attribute is accessed through the *owner*. This method should\n return the (computed) attribute value or raise an "AttributeError"\n exception.\n\nobject.__set__(self, instance, value)\n\n Called to set the attribute on an instance *instance* of the owner\n class to a new value, *value*.\n\nobject.__delete__(self, instance)\n\n Called to delete the attribute on an instance *instance* of the\n owner class.\n\n\nInvoking Descriptors\n--------------------\n\nIn general, a descriptor is an object attribute with "binding\nbehavior", one whose attribute access has been overridden by methods\nin the descriptor protocol: "__get__()", "__set__()", and\n"__delete__()". If any of those methods are defined for an object, it\nis said to be a descriptor.\n\nThe default behavior for attribute access is to get, set, or delete\nthe attribute from an object\'s dictionary. For instance, "a.x" has a\nlookup chain starting with "a.__dict__[\'x\']", then\n"type(a).__dict__[\'x\']", and continuing through the base classes of\n"type(a)" excluding metaclasses.\n\nHowever, if the looked-up value is an object defining one of the\ndescriptor methods, then Python may override the default behavior and\ninvoke the descriptor method instead. Where this occurs in the\nprecedence chain depends on which descriptor methods were defined and\nhow they were called.\n\nThe starting point for descriptor invocation is a binding, "a.x". How\nthe arguments are assembled depends on "a":\n\nDirect Call\n The simplest and least common call is when user code directly\n invokes a descriptor method: "x.__get__(a)".\n\nInstance Binding\n If binding to an object instance, "a.x" is transformed into the\n call: "type(a).__dict__[\'x\'].__get__(a, type(a))".\n\nClass Binding\n If binding to a class, "A.x" is transformed into the call:\n "A.__dict__[\'x\'].__get__(None, A)".\n\nSuper Binding\n If "a" is an instance of "super", then the binding "super(B,\n obj).m()" searches "obj.__class__.__mro__" for the base class "A"\n immediately preceding "B" and then invokes the descriptor with the\n call: "A.__dict__[\'m\'].__get__(obj, obj.__class__)".\n\nFor instance bindings, the precedence of descriptor invocation depends\non the which descriptor methods are defined. A descriptor can define\nany combination of "__get__()", "__set__()" and "__delete__()". If it\ndoes not define "__get__()", then accessing the attribute will return\nthe descriptor object itself unless there is a value in the object\'s\ninstance dictionary. If the descriptor defines "__set__()" and/or\n"__delete__()", it is a data descriptor; if it defines neither, it is\na non-data descriptor. Normally, data descriptors define both\n"__get__()" and "__set__()", while non-data descriptors have just the\n"__get__()" method. Data descriptors with "__set__()" and "__get__()"\ndefined always override a redefinition in an instance dictionary. In\ncontrast, non-data descriptors can be overridden by instances.\n\nPython methods (including "staticmethod()" and "classmethod()") are\nimplemented as non-data descriptors. Accordingly, instances can\nredefine and override methods. This allows individual instances to\nacquire behaviors that differ from other instances of the same class.\n\nThe "property()" function is implemented as a data descriptor.\nAccordingly, instances cannot override the behavior of a property.\n\n\n__slots__\n---------\n\nBy default, instances of classes have a dictionary for attribute\nstorage. This wastes space for objects having very few instance\nvariables. The space consumption can become acute when creating large\nnumbers of instances.\n\nThe default can be overridden by defining *__slots__* in a class\ndefinition. The *__slots__* declaration takes a sequence of instance\nvariables and reserves just enough space in each instance to hold a\nvalue for each variable. Space is saved because *__dict__* is not\ncreated for each instance.\n\nobject.__slots__\n\n This class variable can be assigned a string, iterable, or sequence\n of strings with variable names used by instances. If defined in a\n class, *__slots__* reserves space for the declared variables and\n prevents the automatic creation of *__dict__* and *__weakref__* for\n each instance.\n\n\nNotes on using *__slots__*\n~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n* When inheriting from a class without *__slots__*, the *__dict__*\n attribute of that class will always be accessible, so a *__slots__*\n definition in the subclass is meaningless.\n\n* Without a *__dict__* variable, instances cannot be assigned new\n variables not listed in the *__slots__* definition. Attempts to\n assign to an unlisted variable name raises "AttributeError". If\n dynamic assignment of new variables is desired, then add\n "\'__dict__\'" to the sequence of strings in the *__slots__*\n declaration.\n\n* Without a *__weakref__* variable for each instance, classes\n defining *__slots__* do not support weak references to its\n instances. If weak reference support is needed, then add\n "\'__weakref__\'" to the sequence of strings in the *__slots__*\n declaration.\n\n* *__slots__* are implemented at the class level by creating\n descriptors (*Implementing Descriptors*) for each variable name. As\n a result, class attributes cannot be used to set default values for\n instance variables defined by *__slots__*; otherwise, the class\n attribute would overwrite the descriptor assignment.\n\n* The action of a *__slots__* declaration is limited to the class\n where it is defined. As a result, subclasses will have a *__dict__*\n unless they also define *__slots__* (which must only contain names\n of any *additional* slots).\n\n* If a class defines a slot also defined in a base class, the\n instance variable defined by the base class slot is inaccessible\n (except by retrieving its descriptor directly from the base class).\n This renders the meaning of the program undefined. In the future, a\n check may be added to prevent this.\n\n* Nonempty *__slots__* does not work for classes derived from\n "variable-length" built-in types such as "int", "bytes" and "tuple".\n\n* Any non-string iterable may be assigned to *__slots__*. Mappings\n may also be used; however, in the future, special meaning may be\n assigned to the values corresponding to each key.\n\n* *__class__* assignment works only if both classes have the same\n *__slots__*.\n\n\nCustomizing class creation\n==========================\n\nBy default, classes are constructed using "type()". The class body is\nexecuted in a new namespace and the class name is bound locally to the\nresult of "type(name, bases, namespace)".\n\nThe class creation process can be customised by passing the\n"metaclass" keyword argument in the class definition line, or by\ninheriting from an existing class that included such an argument. In\nthe following example, both "MyClass" and "MySubclass" are instances\nof "Meta":\n\n class Meta(type):\n pass\n\n class MyClass(metaclass=Meta):\n pass\n\n class MySubclass(MyClass):\n pass\n\nAny other keyword arguments that are specified in the class definition\nare passed through to all metaclass operations described below.\n\nWhen a class definition is executed, the following steps occur:\n\n* the appropriate metaclass is determined\n\n* the class namespace is prepared\n\n* the class body is executed\n\n* the class object is created\n\n\nDetermining the appropriate metaclass\n-------------------------------------\n\nThe appropriate metaclass for a class definition is determined as\nfollows:\n\n* if no bases and no explicit metaclass are given, then "type()" is\n used\n\n* if an explicit metaclass is given and it is *not* an instance of\n "type()", then it is used directly as the metaclass\n\n* if an instance of "type()" is given as the explicit metaclass, or\n bases are defined, then the most derived metaclass is used\n\nThe most derived metaclass is selected from the explicitly specified\nmetaclass (if any) and the metaclasses (i.e. "type(cls)") of all\nspecified base classes. The most derived metaclass is one which is a\nsubtype of *all* of these candidate metaclasses. If none of the\ncandidate metaclasses meets that criterion, then the class definition\nwill fail with "TypeError".\n\n\nPreparing the class namespace\n-----------------------------\n\nOnce the appropriate metaclass has been identified, then the class\nnamespace is prepared. If the metaclass has a "__prepare__" attribute,\nit is called as "namespace = metaclass.__prepare__(name, bases,\n**kwds)" (where the additional keyword arguments, if any, come from\nthe class definition).\n\nIf the metaclass has no "__prepare__" attribute, then the class\nnamespace is initialised as an empty "dict()" instance.\n\nSee also: **PEP 3115** - Metaclasses in Python 3000\n\n Introduced the "__prepare__" namespace hook\n\n\nExecuting the class body\n------------------------\n\nThe class body is executed (approximately) as "exec(body, globals(),\nnamespace)". The key difference from a normal call to "exec()" is that\nlexical scoping allows the class body (including any methods) to\nreference names from the current and outer scopes when the class\ndefinition occurs inside a function.\n\nHowever, even when the class definition occurs inside the function,\nmethods defined inside the class still cannot see names defined at the\nclass scope. Class variables must be accessed through the first\nparameter of instance or class methods, and cannot be accessed at all\nfrom static methods.\n\n\nCreating the class object\n-------------------------\n\nOnce the class namespace has been populated by executing the class\nbody, the class object is created by calling "metaclass(name, bases,\nnamespace, **kwds)" (the additional keywords passed here are the same\nas those passed to "__prepare__").\n\nThis class object is the one that will be referenced by the zero-\nargument form of "super()". "__class__" is an implicit closure\nreference created by the compiler if any methods in a class body refer\nto either "__class__" or "super". This allows the zero argument form\nof "super()" to correctly identify the class being defined based on\nlexical scoping, while the class or instance that was used to make the\ncurrent call is identified based on the first argument passed to the\nmethod.\n\nAfter the class object is created, it is passed to the class\ndecorators included in the class definition (if any) and the resulting\nobject is bound in the local namespace as the defined class.\n\nSee also: **PEP 3135** - New super\n\n Describes the implicit "__class__" closure reference\n\n\nMetaclass example\n-----------------\n\nThe potential uses for metaclasses are boundless. Some ideas that have\nbeen explored include logging, interface checking, automatic\ndelegation, automatic property creation, proxies, frameworks, and\nautomatic resource locking/synchronization.\n\nHere is an example of a metaclass that uses an\n"collections.OrderedDict" to remember the order that class members\nwere defined:\n\n class OrderedClass(type):\n\n @classmethod\n def __prepare__(metacls, name, bases, **kwds):\n return collections.OrderedDict()\n\n def __new__(cls, name, bases, namespace, **kwds):\n result = type.__new__(cls, name, bases, dict(namespace))\n result.members = tuple(namespace)\n return result\n\n class A(metaclass=OrderedClass):\n def one(self): pass\n def two(self): pass\n def three(self): pass\n def four(self): pass\n\n >>> A.members\n (\'__module__\', \'one\', \'two\', \'three\', \'four\')\n\nWhen the class definition for *A* gets executed, the process begins\nwith calling the metaclass\'s "__prepare__()" method which returns an\nempty "collections.OrderedDict". That mapping records the methods and\nattributes of *A* as they are defined within the body of the class\nstatement. Once those definitions are executed, the ordered dictionary\nis fully populated and the metaclass\'s "__new__()" method gets\ninvoked. That method builds the new type and it saves the ordered\ndictionary keys in an attribute called "members".\n\n\nCustomizing instance and subclass checks\n========================================\n\nThe following methods are used to override the default behavior of the\n"isinstance()" and "issubclass()" built-in functions.\n\nIn particular, the metaclass "abc.ABCMeta" implements these methods in\norder to allow the addition of Abstract Base Classes (ABCs) as\n"virtual base classes" to any class or type (including built-in\ntypes), including other ABCs.\n\nclass.__instancecheck__(self, instance)\n\n Return true if *instance* should be considered a (direct or\n indirect) instance of *class*. If defined, called to implement\n "isinstance(instance, class)".\n\nclass.__subclasscheck__(self, subclass)\n\n Return true if *subclass* should be considered a (direct or\n indirect) subclass of *class*. If defined, called to implement\n "issubclass(subclass, class)".\n\nNote that these methods are looked up on the type (metaclass) of a\nclass. They cannot be defined as class methods in the actual class.\nThis is consistent with the lookup of special methods that are called\non instances, only in this case the instance is itself a class.\n\nSee also: **PEP 3119** - Introducing Abstract Base Classes\n\n Includes the specification for customizing "isinstance()" and\n "issubclass()" behavior through "__instancecheck__()" and\n "__subclasscheck__()", with motivation for this functionality in\n the context of adding Abstract Base Classes (see the "abc"\n module) to the language.\n\n\nEmulating callable objects\n==========================\n\nobject.__call__(self[, args...])\n\n Called when the instance is "called" as a function; if this method\n is defined, "x(arg1, arg2, ...)" is a shorthand for\n "x.__call__(arg1, arg2, ...)".\n\n\nEmulating container types\n=========================\n\nThe following methods can be defined to implement container objects.\nContainers usually are sequences (such as lists or tuples) or mappings\n(like dictionaries), but can represent other containers as well. The\nfirst set of methods is used either to emulate a sequence or to\nemulate a mapping; the difference is that for a sequence, the\nallowable keys should be the integers *k* for which "0 <= k < N" where\n*N* is the length of the sequence, or slice objects, which define a\nrange of items. It is also recommended that mappings provide the\nmethods "keys()", "values()", "items()", "get()", "clear()",\n"setdefault()", "pop()", "popitem()", "copy()", and "update()"\nbehaving similar to those for Python\'s standard dictionary objects.\nThe "collections" module provides a "MutableMapping" abstract base\nclass to help create those methods from a base set of "__getitem__()",\n"__setitem__()", "__delitem__()", and "keys()". Mutable sequences\nshould provide methods "append()", "count()", "index()", "extend()",\n"insert()", "pop()", "remove()", "reverse()" and "sort()", like Python\nstandard list objects. Finally, sequence types should implement\naddition (meaning concatenation) and multiplication (meaning\nrepetition) by defining the methods "__add__()", "__radd__()",\n"__iadd__()", "__mul__()", "__rmul__()" and "__imul__()" described\nbelow; they should not define other numerical operators. It is\nrecommended that both mappings and sequences implement the\n"__contains__()" method to allow efficient use of the "in" operator;\nfor mappings, "in" should search the mapping\'s keys; for sequences, it\nshould search through the values. It is further recommended that both\nmappings and sequences implement the "__iter__()" method to allow\nefficient iteration through the container; for mappings, "__iter__()"\nshould be the same as "keys()"; for sequences, it should iterate\nthrough the values.\n\nobject.__len__(self)\n\n Called to implement the built-in function "len()". Should return\n the length of the object, an integer ">=" 0. Also, an object that\n doesn\'t define a "__bool__()" method and whose "__len__()" method\n returns zero is considered to be false in a Boolean context.\n\nobject.__length_hint__(self)\n\n Called to implement "operator.length_hint()". Should return an\n estimated length for the object (which may be greater or less than\n the actual length). The length must be an integer ">=" 0. This\n method is purely an optimization and is never required for\n correctness.\n\n New in version 3.4.\n\nNote: Slicing is done exclusively with the following three methods.\n A call like\n\n a[1:2] = b\n\n is translated to\n\n a[slice(1, 2, None)] = b\n\n and so forth. Missing slice items are always filled in with "None".\n\nobject.__getitem__(self, key)\n\n Called to implement evaluation of "self[key]". For sequence types,\n the accepted keys should be integers and slice objects. Note that\n the special interpretation of negative indexes (if the class wishes\n to emulate a sequence type) is up to the "__getitem__()" method. If\n *key* is of an inappropriate type, "TypeError" may be raised; if of\n a value outside the set of indexes for the sequence (after any\n special interpretation of negative values), "IndexError" should be\n raised. For mapping types, if *key* is missing (not in the\n container), "KeyError" should be raised.\n\n Note: "for" loops expect that an "IndexError" will be raised for\n illegal indexes to allow proper detection of the end of the\n sequence.\n\nobject.__setitem__(self, key, value)\n\n Called to implement assignment to "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support changes to the values for keys, or if new keys\n can be added, or for sequences if elements can be replaced. The\n same exceptions should be raised for improper *key* values as for\n the "__getitem__()" method.\n\nobject.__delitem__(self, key)\n\n Called to implement deletion of "self[key]". Same note as for\n "__getitem__()". This should only be implemented for mappings if\n the objects support removal of keys, or for sequences if elements\n can be removed from the sequence. The same exceptions should be\n raised for improper *key* values as for the "__getitem__()" method.\n\nobject.__iter__(self)\n\n This method is called when an iterator is required for a container.\n This method should return a new iterator object that can iterate\n over all the objects in the container. For mappings, it should\n iterate over the keys of the container, and should also be made\n available as the method "keys()".\n\n Iterator objects also need to implement this method; they are\n required to return themselves. For more information on iterator\n objects, see *Iterator Types*.\n\nobject.__reversed__(self)\n\n Called (if present) by the "reversed()" built-in to implement\n reverse iteration. It should return a new iterator object that\n iterates over all the objects in the container in reverse order.\n\n If the "__reversed__()" method is not provided, the "reversed()"\n built-in will fall back to using the sequence protocol ("__len__()"\n and "__getitem__()"). Objects that support the sequence protocol\n should only provide "__reversed__()" if they can provide an\n implementation that is more efficient than the one provided by\n "reversed()".\n\nThe membership test operators ("in" and "not in") are normally\nimplemented as an iteration through a sequence. However, container\nobjects can supply the following special method with a more efficient\nimplementation, which also does not require the object be a sequence.\n\nobject.__contains__(self, item)\n\n Called to implement membership test operators. Should return true\n if *item* is in *self*, false otherwise. For mapping objects, this\n should consider the keys of the mapping rather than the values or\n the key-item pairs.\n\n For objects that don\'t define "__contains__()", the membership test\n first tries iteration via "__iter__()", then the old sequence\n iteration protocol via "__getitem__()", see *this section in the\n language reference*.\n\n\nEmulating numeric types\n=======================\n\nThe following methods can be defined to emulate numeric objects.\nMethods corresponding to operations that are not supported by the\nparticular kind of number implemented (e.g., bitwise operations for\nnon-integral numbers) should be left undefined.\n\nobject.__add__(self, other)\nobject.__sub__(self, other)\nobject.__mul__(self, other)\nobject.__truediv__(self, other)\nobject.__floordiv__(self, other)\nobject.__mod__(self, other)\nobject.__divmod__(self, other)\nobject.__pow__(self, other[, modulo])\nobject.__lshift__(self, other)\nobject.__rshift__(self, other)\nobject.__and__(self, other)\nobject.__xor__(self, other)\nobject.__or__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|"). For instance, to evaluate the\n expression "x + y", where *x* is an instance of a class that has an\n "__add__()" method, "x.__add__(y)" is called. The "__divmod__()"\n method should be the equivalent to using "__floordiv__()" and\n "__mod__()"; it should not be related to "__truediv__()". Note\n that "__pow__()" should be defined to accept an optional third\n argument if the ternary version of the built-in "pow()" function is\n to be supported.\n\n If one of those methods does not support the operation with the\n supplied arguments, it should return "NotImplemented".\n\nobject.__radd__(self, other)\nobject.__rsub__(self, other)\nobject.__rmul__(self, other)\nobject.__rtruediv__(self, other)\nobject.__rfloordiv__(self, other)\nobject.__rmod__(self, other)\nobject.__rdivmod__(self, other)\nobject.__rpow__(self, other)\nobject.__rlshift__(self, other)\nobject.__rrshift__(self, other)\nobject.__rand__(self, other)\nobject.__rxor__(self, other)\nobject.__ror__(self, other)\n\n These methods are called to implement the binary arithmetic\n operations ("+", "-", "*", "/", "//", "%", "divmod()", "pow()",\n "**", "<<", ">>", "&", "^", "|") with reflected (swapped) operands.\n These functions are only called if the left operand does not\n support the corresponding operation and the operands are of\n different types. [2] For instance, to evaluate the expression "x -\n y", where *y* is an instance of a class that has an "__rsub__()"\n method, "y.__rsub__(x)" is called if "x.__sub__(y)" returns\n *NotImplemented*.\n\n Note that ternary "pow()" will not try calling "__rpow__()" (the\n coercion rules would become too complicated).\n\n Note: If the right operand\'s type is a subclass of the left\n operand\'s type and that subclass provides the reflected method\n for the operation, this method will be called before the left\n operand\'s non-reflected method. This behavior allows subclasses\n to override their ancestors\' operations.\n\nobject.__iadd__(self, other)\nobject.__isub__(self, other)\nobject.__imul__(self, other)\nobject.__itruediv__(self, other)\nobject.__ifloordiv__(self, other)\nobject.__imod__(self, other)\nobject.__ipow__(self, other[, modulo])\nobject.__ilshift__(self, other)\nobject.__irshift__(self, other)\nobject.__iand__(self, other)\nobject.__ixor__(self, other)\nobject.__ior__(self, other)\n\n These methods are called to implement the augmented arithmetic\n assignments ("+=", "-=", "*=", "/=", "//=", "%=", "**=", "<<=",\n ">>=", "&=", "^=", "|="). These methods should attempt to do the\n operation in-place (modifying *self*) and return the result (which\n could be, but does not have to be, *self*). If a specific method\n is not defined, the augmented assignment falls back to the normal\n methods. For instance, to execute the statement "x += y", where\n *x* is an instance of a class that has an "__iadd__()" method,\n "x.__iadd__(y)" is called. If *x* is an instance of a class that\n does not define a "__iadd__()" method, "x.__add__(y)" and\n "y.__radd__(x)" are considered, as with the evaluation of "x + y".\n\nobject.__neg__(self)\nobject.__pos__(self)\nobject.__abs__(self)\nobject.__invert__(self)\n\n Called to implement the unary arithmetic operations ("-", "+",\n "abs()" and "~").\n\nobject.__complex__(self)\nobject.__int__(self)\nobject.__float__(self)\nobject.__round__(self[, n])\n\n Called to implement the built-in functions "complex()", "int()",\n "float()" and "round()". Should return a value of the appropriate\n type.\n\nobject.__index__(self)\n\n Called to implement "operator.index()", and whenever Python needs\n to losslessly convert the numeric object to an integer object (such\n as in slicing, or in the built-in "bin()", "hex()" and "oct()"\n functions). Presence of this method indicates that the numeric\n object is an integer type. Must return an integer.\n\n Note: When "__index__()" is defined, "__int__()" should also be\n defined, and both shuld return the same value, in order to have a\n coherent integer type class.\n\n\nWith Statement Context Managers\n===============================\n\nA *context manager* is an object that defines the runtime context to\nbe established when executing a "with" statement. The context manager\nhandles the entry into, and the exit from, the desired runtime context\nfor the execution of the block of code. Context managers are normally\ninvoked using the "with" statement (described in section *The with\nstatement*), but can also be used by directly invoking their methods.\n\nTypical uses of context managers include saving and restoring various\nkinds of global state, locking and unlocking resources, closing opened\nfiles, etc.\n\nFor more information on context managers, see *Context Manager Types*.\n\nobject.__enter__(self)\n\n Enter the runtime context related to this object. The "with"\n statement will bind this method\'s return value to the target(s)\n specified in the "as" clause of the statement, if any.\n\nobject.__exit__(self, exc_type, exc_value, traceback)\n\n Exit the runtime context related to this object. The parameters\n describe the exception that caused the context to be exited. If the\n context was exited without an exception, all three arguments will\n be "None".\n\n If an exception is supplied, and the method wishes to suppress the\n exception (i.e., prevent it from being propagated), it should\n return a true value. Otherwise, the exception will be processed\n normally upon exit from this method.\n\n Note that "__exit__()" methods should not reraise the passed-in\n exception; this is the caller\'s responsibility.\n\nSee also: **PEP 0343** - The "with" statement\n\n The specification, background, and examples for the Python "with"\n statement.\n\n\nSpecial method lookup\n=====================\n\nFor custom classes, implicit invocations of special methods are only\nguaranteed to work correctly if defined on an object\'s type, not in\nthe object\'s instance dictionary. That behaviour is the reason why\nthe following code raises an exception:\n\n >>> class C:\n ... pass\n ...\n >>> c = C()\n >>> c.__len__ = lambda: 5\n >>> len(c)\n Traceback (most recent call last):\n File "<stdin>", line 1, in <module>\n TypeError: object of type \'C\' has no len()\n\nThe rationale behind this behaviour lies with a number of special\nmethods such as "__hash__()" and "__repr__()" that are implemented by\nall objects, including type objects. If the implicit lookup of these\nmethods used the conventional lookup process, they would fail when\ninvoked on the type object itself:\n\n >>> 1 .__hash__() == hash(1)\n True\n >>> int.__hash__() == hash(int)\n Traceback (most recent call last):\n File "<stdin>", line 1, in <module>\n TypeError: descriptor \'__hash__\' of \'int\' object needs an argument\n\nIncorrectly attempting to invoke an unbound method of a class in this\nway is sometimes referred to as \'metaclass confusion\', and is avoided\nby bypassing the instance when looking up special methods:\n\n >>> type(1).__hash__(1) == hash(1)\n True\n >>> type(int).__hash__(int) == hash(int)\n True\n\nIn addition to bypassing any instance attributes in the interest of\ncorrectness, implicit special method lookup generally also bypasses\nthe "__getattribute__()" method even of the object\'s metaclass:\n\n >>> class Meta(type):\n ... def __getattribute__(*args):\n ... print("Metaclass getattribute invoked")\n ... return type.__getattribute__(*args)\n ...\n >>> class C(object, metaclass=Meta):\n ... def __len__(self):\n ... return 10\n ... def __getattribute__(*args):\n ... print("Class getattribute invoked")\n ... return object.__getattribute__(*args)\n ...\n >>> c = C()\n >>> c.__len__() # Explicit lookup via instance\n Class getattribute invoked\n 10\n >>> type(c).__len__(c) # Explicit lookup via type\n Metaclass getattribute invoked\n 10\n >>> len(c) # Implicit lookup\n 10\n\nBypassing the "__getattribute__()" machinery in this fashion provides\nsignificant scope for speed optimisations within the interpreter, at\nthe cost of some flexibility in the handling of special methods (the\nspecial method *must* be set on the class object itself in order to be\nconsistently invoked by the interpreter).\n\n-[ Footnotes ]-\n\n[1] It *is* possible in some cases to change an object\'s type,\n under certain controlled conditions. It generally isn\'t a good\n idea though, since it can lead to some very strange behaviour if\n it is handled incorrectly.\n\n[2] For operands of the same type, it is assumed that if the non-\n reflected method (such as "__add__()") fails the operation is not\n supported, which is why the reflected method is not called.\n', + 'string-methods': '\nString Methods\n**************\n\nStrings implement all of the *common* sequence operations, along with\nthe additional methods described below.\n\nStrings also support two styles of string formatting, one providing a\nlarge degree of flexibility and customization (see "str.format()",\n*Format String Syntax* and *String Formatting*) and the other based on\nC "printf" style formatting that handles a narrower range of types and\nis slightly harder to use correctly, but is often faster for the cases\nit can handle (*printf-style String Formatting*).\n\nThe *Text Processing Services* section of the standard library covers\na number of other modules that provide various text related utilities\n(including regular expression support in the "re" module).\n\nstr.capitalize()\n\n Return a copy of the string with its first character capitalized\n and the rest lowercased.\n\nstr.casefold()\n\n Return a casefolded copy of the string. Casefolded strings may be\n used for caseless matching.\n\n Casefolding is similar to lowercasing but more aggressive because\n it is intended to remove all case distinctions in a string. For\n example, the German lowercase letter "\'\xc3\x9f\'" is equivalent to ""ss"".\n Since it is already lowercase, "lower()" would do nothing to "\'\xc3\x9f\'";\n "casefold()" converts it to ""ss"".\n\n The casefolding algorithm is described in section 3.13 of the\n Unicode Standard.\n\n New in version 3.3.\n\nstr.center(width[, fillchar])\n\n Return centered in a string of length *width*. Padding is done\n using the specified *fillchar* (default is a space).\n\nstr.count(sub[, start[, end]])\n\n Return the number of non-overlapping occurrences of substring *sub*\n in the range [*start*, *end*]. Optional arguments *start* and\n *end* are interpreted as in slice notation.\n\nstr.encode(encoding="utf-8", errors="strict")\n\n Return an encoded version of the string as a bytes object. Default\n encoding is "\'utf-8\'". *errors* may be given to set a different\n error handling scheme. The default for *errors* is "\'strict\'",\n meaning that encoding errors raise a "UnicodeError". Other possible\n values are "\'ignore\'", "\'replace\'", "\'xmlcharrefreplace\'",\n "\'backslashreplace\'" and any other name registered via\n "codecs.register_error()", see section *Codec Base Classes*. For a\n list of possible encodings, see section *Standard Encodings*.\n\n Changed in version 3.1: Support for keyword arguments added.\n\nstr.endswith(suffix[, start[, end]])\n\n Return "True" if the string ends with the specified *suffix*,\n otherwise return "False". *suffix* can also be a tuple of suffixes\n to look for. With optional *start*, test beginning at that\n position. With optional *end*, stop comparing at that position.\n\nstr.expandtabs(tabsize=8)\n\n Return a copy of the string where all tab characters are replaced\n by one or more spaces, depending on the current column and the\n given tab size. Tab positions occur every *tabsize* characters\n (default is 8, giving tab positions at columns 0, 8, 16 and so on).\n To expand the string, the current column is set to zero and the\n string is examined character by character. If the character is a\n tab ("\\t"), one or more space characters are inserted in the result\n until the current column is equal to the next tab position. (The\n tab character itself is not copied.) If the character is a newline\n ("\\n") or return ("\\r"), it is copied and the current column is\n reset to zero. Any other character is copied unchanged and the\n current column is incremented by one regardless of how the\n character is represented when printed.\n\n >>> \'01\\t012\\t0123\\t01234\'.expandtabs()\n \'01 012 0123 01234\'\n >>> \'01\\t012\\t0123\\t01234\'.expandtabs(4)\n \'01 012 0123 01234\'\n\nstr.find(sub[, start[, end]])\n\n Return the lowest index in the string where substring *sub* is\n found, such that *sub* is contained in the slice "s[start:end]".\n Optional arguments *start* and *end* are interpreted as in slice\n notation. Return "-1" if *sub* is not found.\n\n Note: The "find()" method should be used only if you need to know\n the position of *sub*. To check if *sub* is a substring or not,\n use the "in" operator:\n\n >>> \'Py\' in \'Python\'\n True\n\nstr.format(*args, **kwargs)\n\n Perform a string formatting operation. The string on which this\n method is called can contain literal text or replacement fields\n delimited by braces "{}". Each replacement field contains either\n the numeric index of a positional argument, or the name of a\n keyword argument. Returns a copy of the string where each\n replacement field is replaced with the string value of the\n corresponding argument.\n\n >>> "The sum of 1 + 2 is {0}".format(1+2)\n \'The sum of 1 + 2 is 3\'\n\n See *Format String Syntax* for a description of the various\n formatting options that can be specified in format strings.\n\nstr.format_map(mapping)\n\n Similar to "str.format(**mapping)", except that "mapping" is used\n directly and not copied to a "dict". This is useful if for example\n "mapping" is a dict subclass:\n\n >>> class Default(dict):\n ... def __missing__(self, key):\n ... return key\n ...\n >>> \'{name} was born in {country}\'.format_map(Default(name=\'Guido\'))\n \'Guido was born in country\'\n\n New in version 3.2.\n\nstr.index(sub[, start[, end]])\n\n Like "find()", but raise "ValueError" when the substring is not\n found.\n\nstr.isalnum()\n\n Return true if all characters in the string are alphanumeric and\n there is at least one character, false otherwise. A character "c"\n is alphanumeric if one of the following returns "True":\n "c.isalpha()", "c.isdecimal()", "c.isdigit()", or "c.isnumeric()".\n\nstr.isalpha()\n\n Return true if all characters in the string are alphabetic and\n there is at least one character, false otherwise. Alphabetic\n characters are those characters defined in the Unicode character\n database as "Letter", i.e., those with general category property\n being one of "Lm", "Lt", "Lu", "Ll", or "Lo". Note that this is\n different from the "Alphabetic" property defined in the Unicode\n Standard.\n\nstr.isdecimal()\n\n Return true if all characters in the string are decimal characters\n and there is at least one character, false otherwise. Decimal\n characters are those from general category "Nd". This category\n includes digit characters, and all characters that can be used to\n form decimal-radix numbers, e.g. U+0660, ARABIC-INDIC DIGIT ZERO.\n\nstr.isdigit()\n\n Return true if all characters in the string are digits and there is\n at least one character, false otherwise. Digits include decimal\n characters and digits that need special handling, such as the\n compatibility superscript digits. Formally, a digit is a character\n that has the property value Numeric_Type=Digit or\n Numeric_Type=Decimal.\n\nstr.isidentifier()\n\n Return true if the string is a valid identifier according to the\n language definition, section *Identifiers and keywords*.\n\n Use "keyword.iskeyword()" to test for reserved identifiers such as\n "def" and "class".\n\nstr.islower()\n\n Return true if all cased characters [4] in the string are lowercase\n and there is at least one cased character, false otherwise.\n\nstr.isnumeric()\n\n Return true if all characters in the string are numeric characters,\n and there is at least one character, false otherwise. Numeric\n characters include digit characters, and all characters that have\n the Unicode numeric value property, e.g. U+2155, VULGAR FRACTION\n ONE FIFTH. Formally, numeric characters are those with the\n property value Numeric_Type=Digit, Numeric_Type=Decimal or\n Numeric_Type=Numeric.\n\nstr.isprintable()\n\n Return true if all characters in the string are printable or the\n string is empty, false otherwise. Nonprintable characters are\n those characters defined in the Unicode character database as\n "Other" or "Separator", excepting the ASCII space (0x20) which is\n considered printable. (Note that printable characters in this\n context are those which should not be escaped when "repr()" is\n invoked on a string. It has no bearing on the handling of strings\n written to "sys.stdout" or "sys.stderr".)\n\nstr.isspace()\n\n Return true if there are only whitespace characters in the string\n and there is at least one character, false otherwise. Whitespace\n characters are those characters defined in the Unicode character\n database as "Other" or "Separator" and those with bidirectional\n property being one of "WS", "B", or "S".\n\nstr.istitle()\n\n Return true if the string is a titlecased string and there is at\n least one character, for example uppercase characters may only\n follow uncased characters and lowercase characters only cased ones.\n Return false otherwise.\n\nstr.isupper()\n\n Return true if all cased characters [4] in the string are uppercase\n and there is at least one cased character, false otherwise.\n\nstr.join(iterable)\n\n Return a string which is the concatenation of the strings in the\n *iterable* *iterable*. A "TypeError" will be raised if there are\n any non-string values in *iterable*, including "bytes" objects.\n The separator between elements is the string providing this method.\n\nstr.ljust(width[, fillchar])\n\n Return the string left justified in a string of length *width*.\n Padding is done using the specified *fillchar* (default is a\n space). The original string is returned if *width* is less than or\n equal to "len(s)".\n\nstr.lower()\n\n Return a copy of the string with all the cased characters [4]\n converted to lowercase.\n\n The lowercasing algorithm used is described in section 3.13 of the\n Unicode Standard.\n\nstr.lstrip([chars])\n\n Return a copy of the string with leading characters removed. The\n *chars* argument is a string specifying the set of characters to be\n removed. If omitted or "None", the *chars* argument defaults to\n removing whitespace. The *chars* argument is not a prefix; rather,\n all combinations of its values are stripped:\n\n >>> \' spacious \'.lstrip()\n \'spacious \'\n >>> \'www.example.com\'.lstrip(\'cmowz.\')\n \'example.com\'\n\nstatic str.maketrans(x[, y[, z]])\n\n This static method returns a translation table usable for\n "str.translate()".\n\n If there is only one argument, it must be a dictionary mapping\n Unicode ordinals (integers) or characters (strings of length 1) to\n Unicode ordinals, strings (of arbitrary lengths) or None.\n Character keys will then be converted to ordinals.\n\n If there are two arguments, they must be strings of equal length,\n and in the resulting dictionary, each character in x will be mapped\n to the character at the same position in y. If there is a third\n argument, it must be a string, whose characters will be mapped to\n None in the result.\n\nstr.partition(sep)\n\n Split the string at the first occurrence of *sep*, and return a\n 3-tuple containing the part before the separator, the separator\n itself, and the part after the separator. If the separator is not\n found, return a 3-tuple containing the string itself, followed by\n two empty strings.\n\nstr.replace(old, new[, count])\n\n Return a copy of the string with all occurrences of substring *old*\n replaced by *new*. If the optional argument *count* is given, only\n the first *count* occurrences are replaced.\n\nstr.rfind(sub[, start[, end]])\n\n Return the highest index in the string where substring *sub* is\n found, such that *sub* is contained within "s[start:end]".\n Optional arguments *start* and *end* are interpreted as in slice\n notation. Return "-1" on failure.\n\nstr.rindex(sub[, start[, end]])\n\n Like "rfind()" but raises "ValueError" when the substring *sub* is\n not found.\n\nstr.rjust(width[, fillchar])\n\n Return the string right justified in a string of length *width*.\n Padding is done using the specified *fillchar* (default is a\n space). The original string is returned if *width* is less than or\n equal to "len(s)".\n\nstr.rpartition(sep)\n\n Split the string at the last occurrence of *sep*, and return a\n 3-tuple containing the part before the separator, the separator\n itself, and the part after the separator. If the separator is not\n found, return a 3-tuple containing two empty strings, followed by\n the string itself.\n\nstr.rsplit(sep=None, maxsplit=-1)\n\n Return a list of the words in the string, using *sep* as the\n delimiter string. If *maxsplit* is given, at most *maxsplit* splits\n are done, the *rightmost* ones. If *sep* is not specified or\n "None", any whitespace string is a separator. Except for splitting\n from the right, "rsplit()" behaves like "split()" which is\n described in detail below.\n\nstr.rstrip([chars])\n\n Return a copy of the string with trailing characters removed. The\n *chars* argument is a string specifying the set of characters to be\n removed. If omitted or "None", the *chars* argument defaults to\n removing whitespace. The *chars* argument is not a suffix; rather,\n all combinations of its values are stripped:\n\n >>> \' spacious \'.rstrip()\n \' spacious\'\n >>> \'mississippi\'.rstrip(\'ipz\')\n \'mississ\'\n\nstr.split(sep=None, maxsplit=-1)\n\n Return a list of the words in the string, using *sep* as the\n delimiter string. If *maxsplit* is given, at most *maxsplit*\n splits are done (thus, the list will have at most "maxsplit+1"\n elements). If *maxsplit* is not specified or "-1", then there is\n no limit on the number of splits (all possible splits are made).\n\n If *sep* is given, consecutive delimiters are not grouped together\n and are deemed to delimit empty strings (for example,\n "\'1,,2\'.split(\',\')" returns "[\'1\', \'\', \'2\']"). The *sep* argument\n may consist of multiple characters (for example,\n "\'1<>2<>3\'.split(\'<>\')" returns "[\'1\', \'2\', \'3\']"). Splitting an\n empty string with a specified separator returns "[\'\']".\n\n If *sep* is not specified or is "None", a different splitting\n algorithm is applied: runs of consecutive whitespace are regarded\n as a single separator, and the result will contain no empty strings\n at the start or end if the string has leading or trailing\n whitespace. Consequently, splitting an empty string or a string\n consisting of just whitespace with a "None" separator returns "[]".\n\n For example, "\' 1 2 3 \'.split()" returns "[\'1\', \'2\', \'3\']", and\n "\' 1 2 3 \'.split(None, 1)" returns "[\'1\', \'2 3 \']".\n\nstr.splitlines([keepends])\n\n Return a list of the lines in the string, breaking at line\n boundaries. This method uses the *universal newlines* approach to\n splitting lines. Line breaks are not included in the resulting list\n unless *keepends* is given and true.\n\n For example, "\'ab c\\n\\nde fg\\rkl\\r\\n\'.splitlines()" returns "[\'ab\n c\', \'\', \'de fg\', \'kl\']", while the same call with\n "splitlines(True)" returns "[\'ab c\\n\', \'\\n\', \'de fg\\r\', \'kl\\r\\n\']".\n\n Unlike "split()" when a delimiter string *sep* is given, this\n method returns an empty list for the empty string, and a terminal\n line break does not result in an extra line.\n\nstr.startswith(prefix[, start[, end]])\n\n Return "True" if string starts with the *prefix*, otherwise return\n "False". *prefix* can also be a tuple of prefixes to look for.\n With optional *start*, test string beginning at that position.\n With optional *end*, stop comparing string at that position.\n\nstr.strip([chars])\n\n Return a copy of the string with the leading and trailing\n characters removed. The *chars* argument is a string specifying the\n set of characters to be removed. If omitted or "None", the *chars*\n argument defaults to removing whitespace. The *chars* argument is\n not a prefix or suffix; rather, all combinations of its values are\n stripped:\n\n >>> \' spacious \'.strip()\n \'spacious\'\n >>> \'www.example.com\'.strip(\'cmowz.\')\n \'example\'\n\nstr.swapcase()\n\n Return a copy of the string with uppercase characters converted to\n lowercase and vice versa. Note that it is not necessarily true that\n "s.swapcase().swapcase() == s".\n\nstr.title()\n\n Return a titlecased version of the string where words start with an\n uppercase character and the remaining characters are lowercase.\n\n The algorithm uses a simple language-independent definition of a\n word as groups of consecutive letters. The definition works in\n many contexts but it means that apostrophes in contractions and\n possessives form word boundaries, which may not be the desired\n result:\n\n >>> "they\'re bill\'s friends from the UK".title()\n "They\'Re Bill\'S Friends From The Uk"\n\n A workaround for apostrophes can be constructed using regular\n expressions:\n\n >>> import re\n >>> def titlecase(s):\n ... return re.sub(r"[A-Za-z]+(\'[A-Za-z]+)?",\n ... lambda mo: mo.group(0)[0].upper() +\n ... mo.group(0)[1:].lower(),\n ... s)\n ...\n >>> titlecase("they\'re bill\'s friends.")\n "They\'re Bill\'s Friends."\n\nstr.translate(map)\n\n Return a copy of the *s* where all characters have been mapped\n through the *map* which must be a dictionary of Unicode ordinals\n (integers) to Unicode ordinals, strings or "None". Unmapped\n characters are left untouched. Characters mapped to "None" are\n deleted.\n\n You can use "str.maketrans()" to create a translation map from\n character-to-character mappings in different formats.\n\n Note: An even more flexible approach is to create a custom\n character mapping codec using the "codecs" module (see\n "encodings.cp1251" for an example).\n\nstr.upper()\n\n Return a copy of the string with all the cased characters [4]\n converted to uppercase. Note that "str.upper().isupper()" might be\n "False" if "s" contains uncased characters or if the Unicode\n category of the resulting character(s) is not "Lu" (Letter,\n uppercase), but e.g. "Lt" (Letter, titlecase).\n\n The uppercasing algorithm used is described in section 3.13 of the\n Unicode Standard.\n\nstr.zfill(width)\n\n Return the numeric string left filled with zeros in a string of\n length *width*. A sign prefix is handled correctly. The original\n string is returned if *width* is less than or equal to "len(s)".\n', + 'strings': '\nString and Bytes literals\n*************************\n\nString literals are described by the following lexical definitions:\n\n stringliteral ::= [stringprefix](shortstring | longstring)\n stringprefix ::= "r" | "u" | "R" | "U"\n shortstring ::= "\'" shortstringitem* "\'" | \'"\' shortstringitem* \'"\'\n longstring ::= "\'\'\'" longstringitem* "\'\'\'" | \'"""\' longstringitem* \'"""\'\n shortstringitem ::= shortstringchar | stringescapeseq\n longstringitem ::= longstringchar | stringescapeseq\n shortstringchar ::= <any source character except "\\" or newline or the quote>\n longstringchar ::= <any source character except "\\">\n stringescapeseq ::= "\\" <any source character>\n\n bytesliteral ::= bytesprefix(shortbytes | longbytes)\n bytesprefix ::= "b" | "B" | "br" | "Br" | "bR" | "BR" | "rb" | "rB" | "Rb" | "RB"\n shortbytes ::= "\'" shortbytesitem* "\'" | \'"\' shortbytesitem* \'"\'\n longbytes ::= "\'\'\'" longbytesitem* "\'\'\'" | \'"""\' longbytesitem* \'"""\'\n shortbytesitem ::= shortbyteschar | bytesescapeseq\n longbytesitem ::= longbyteschar | bytesescapeseq\n shortbyteschar ::= <any ASCII character except "\\" or newline or the quote>\n longbyteschar ::= <any ASCII character except "\\">\n bytesescapeseq ::= "\\" <any ASCII character>\n\nOne syntactic restriction not indicated by these productions is that\nwhitespace is not allowed between the "stringprefix" or "bytesprefix"\nand the rest of the literal. The source character set is defined by\nthe encoding declaration; it is UTF-8 if no encoding declaration is\ngiven in the source file; see section *Encoding declarations*.\n\nIn plain English: Both types of literals can be enclosed in matching\nsingle quotes ("\'") or double quotes ("""). They can also be enclosed\nin matching groups of three single or double quotes (these are\ngenerally referred to as *triple-quoted strings*). The backslash\n("\\") character is used to escape characters that otherwise have a\nspecial meaning, such as newline, backslash itself, or the quote\ncharacter.\n\nBytes literals are always prefixed with "\'b\'" or "\'B\'"; they produce\nan instance of the "bytes" type instead of the "str" type. They may\nonly contain ASCII characters; bytes with a numeric value of 128 or\ngreater must be expressed with escapes.\n\nAs of Python 3.3 it is possible again to prefix unicode strings with a\n"u" prefix to simplify maintenance of dual 2.x and 3.x codebases.\n\nBoth string and bytes literals may optionally be prefixed with a\nletter "\'r\'" or "\'R\'"; such strings are called *raw strings* and treat\nbackslashes as literal characters. As a result, in string literals,\n"\'\\U\'" and "\'\\u\'" escapes in raw strings are not treated specially.\nGiven that Python 2.x\'s raw unicode literals behave differently than\nPython 3.x\'s the "\'ur\'" syntax is not supported.\n\n New in version 3.3: The "\'rb\'" prefix of raw bytes literals has\n been added as a synonym of "\'br\'".\n\n New in version 3.3: Support for the unicode legacy literal\n ("u\'value\'") was reintroduced to simplify the maintenance of dual\n Python 2.x and 3.x codebases. See **PEP 414** for more information.\n\nIn triple-quoted strings, unescaped newlines and quotes are allowed\n(and are retained), except that three unescaped quotes in a row\nterminate the string. (A "quote" is the character used to open the\nstring, i.e. either "\'" or """.)\n\nUnless an "\'r\'" or "\'R\'" prefix is present, escape sequences in\nstrings are interpreted according to rules similar to those used by\nStandard C. The recognized escape sequences are:\n\n+-------------------+-----------------------------------+---------+\n| Escape Sequence | Meaning | Notes |\n+===================+===================================+=========+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n+-------------------+-----------------------------------+---------+\n| "\\ooo" | Character with octal value *ooo* | (1,3) |\n+-------------------+-----------------------------------+---------+\n| "\\xhh" | Character with hex value *hh* | (2,3) |\n+-------------------+-----------------------------------+---------+\n\nEscape sequences only recognized in string literals are:\n\n+-------------------+-----------------------------------+---------+\n| Escape Sequence | Meaning | Notes |\n+===================+===================================+=========+\n| "\\N{name}" | Character named *name* in the | (4) |\n+-------------------+-----------------------------------+---------+\n| "\\uxxxx" | Character with 16-bit hex value | (5) |\n+-------------------+-----------------------------------+---------+\n| "\\Uxxxxxxxx" | Character with 32-bit hex value | (6) |\n+-------------------+-----------------------------------+---------+\n\nNotes:\n\n1. As in Standard C, up to three octal digits are accepted.\n\n2. Unlike in Standard C, exactly two hex digits are required.\n\n3. In a bytes literal, hexadecimal and octal escapes denote the\n byte with the given value. In a string literal, these escapes\n denote a Unicode character with the given value.\n\n4. Changed in version 3.3: Support for name aliases [1] has been\n added.\n\n5. Individual code units which form parts of a surrogate pair can\n be encoded using this escape sequence. Exactly four hex digits are\n required.\n\n6. Any Unicode character can be encoded this way. Exactly eight\n hex digits are required.\n\nUnlike Standard C, all unrecognized escape sequences are left in the\nstring unchanged, i.e., *the backslash is left in the string*. (This\nbehavior is useful when debugging: if an escape sequence is mistyped,\nthe resulting output is more easily recognized as broken.) It is also\nimportant to note that the escape sequences only recognized in string\nliterals fall into the category of unrecognized escapes for bytes\nliterals.\n\nEven in a raw string, string quotes can be escaped with a backslash,\nbut the backslash remains in the string; for example, "r"\\""" is a\nvalid string literal consisting of two characters: a backslash and a\ndouble quote; "r"\\"" is not a valid string literal (even a raw string\ncannot end in an odd number of backslashes). Specifically, *a raw\nstring cannot end in a single backslash* (since the backslash would\nescape the following quote character). Note also that a single\nbackslash followed by a newline is interpreted as those two characters\nas part of the string, *not* as a line continuation.\n', 'subscriptions': '\nSubscriptions\n*************\n\nA subscription selects an item of a sequence (string, tuple or list)\nor mapping (dictionary) object:\n\n subscription ::= primary "[" expression_list "]"\n\nThe primary must evaluate to an object that supports subscription,\ne.g. a list or dictionary. User-defined objects can support\nsubscription by defining a "__getitem__()" method.\n\nFor built-in objects, there are two types of objects that support\nsubscription:\n\nIf the primary is a mapping, the expression list must evaluate to an\nobject whose value is one of the keys of the mapping, and the\nsubscription selects the value in the mapping that corresponds to that\nkey. (The expression list is a tuple except if it has exactly one\nitem.)\n\nIf the primary is a sequence, the expression (list) must evaluate to\nan integer or a slice (as discussed in the following section).\n\nThe formal syntax makes no special provision for negative indices in\nsequences; however, built-in sequences all provide a "__getitem__()"\nmethod that interprets negative indices by adding the length of the\nsequence to the index (so that "x[-1]" selects the last item of "x").\nThe resulting value must be a nonnegative integer less than the number\nof items in the sequence, and the subscription selects the item whose\nindex is that value (counting from zero). Since the support for\nnegative indices and slicing occurs in the object\'s "__getitem__()"\nmethod, subclasses overriding this method will need to explicitly add\nthat support.\n\nA string\'s items are characters. A character is not a separate data\ntype but a string of exactly one character.\n', 'truth': '\nTruth Value Testing\n*******************\n\nAny object can be tested for truth value, for use in an "if" or\n"while" condition or as operand of the Boolean operations below. The\nfollowing values are considered false:\n\n* "None"\n\n* "False"\n\n* zero of any numeric type, for example, "0", "0.0", "0j".\n\n* any empty sequence, for example, "\'\'", "()", "[]".\n\n* any empty mapping, for example, "{}".\n\n* instances of user-defined classes, if the class defines a\n "__bool__()" or "__len__()" method, when that method returns the\n integer zero or "bool" value "False". [1]\n\nAll other values are considered true --- so objects of many types are\nalways true.\n\nOperations and built-in functions that have a Boolean result always\nreturn "0" or "False" for false and "1" or "True" for true, unless\notherwise stated. (Important exception: the Boolean operations "or"\nand "and" always return one of their operands.)\n', - 'try': '\nThe "try" statement\n*******************\n\nThe "try" statement specifies exception handlers and/or cleanup code\nfor a group of statements:\n\n try_stmt ::= try1_stmt | try2_stmt\n try1_stmt ::= "try" ":" suite\n ("except" [expression ["as" target]] ":" suite)+\n ["else" ":" suite]\n ["finally" ":" suite]\n try2_stmt ::= "try" ":" suite\n "finally" ":" suite\n\nThe "except" clause(s) specify one or more exception handlers. When no\nexception occurs in the "try" clause, no exception handler is\nexecuted. When an exception occurs in the "try" suite, a search for an\nexception handler is started. This search inspects the except clauses\nin turn until one is found that matches the exception. An expression-\nless except clause, if present, must be last; it matches any\nexception. For an except clause with an expression, that expression\nis evaluated, and the clause matches the exception if the resulting\nobject is "compatible" with the exception. An object is compatible\nwith an exception if it is the class or a base class of the exception\nobject or a tuple containing an item compatible with the exception.\n\nIf no except clause matches the exception, the search for an exception\nhandler continues in the surrounding code and on the invocation stack.\n[1]\n\nIf the evaluation of an expression in the header of an except clause\nraises an exception, the original search for a handler is canceled and\na search starts for the new exception in the surrounding code and on\nthe call stack (it is treated as if the entire "try" statement raised\nthe exception).\n\nWhen a matching except clause is found, the exception is assigned to\nthe target specified after the "as" keyword in that except clause, if\npresent, and the except clause\'s suite is executed. All except\nclauses must have an executable block. When the end of this block is\nreached, execution continues normally after the entire try statement.\n(This means that if two nested handlers exist for the same exception,\nand the exception occurs in the try clause of the inner handler, the\nouter handler will not handle the exception.)\n\nWhen an exception has been assigned using "as target", it is cleared\nat the end of the except clause. This is as if\n\n except E as N:\n foo\n\nwas translated to\n\n except E as N:\n try:\n foo\n finally:\n del N\n\nThis means the exception must be assigned to a different name to be\nable to refer to it after the except clause. Exceptions are cleared\nbecause with the traceback attached to them, they form a reference\ncycle with the stack frame, keeping all locals in that frame alive\nuntil the next garbage collection occurs.\n\nBefore an except clause\'s suite is executed, details about the\nexception are stored in the "sys" module and can be access via\n"sys.exc_info()". "sys.exc_info()" returns a 3-tuple consisting of the\nexception class, the exception instance and a traceback object (see\nsection *The standard type hierarchy*) identifying the point in the\nprogram where the exception occurred. "sys.exc_info()" values are\nrestored to their previous values (before the call) when returning\nfrom a function that handled an exception.\n\nThe optional "else" clause is executed if and when control flows off\nthe end of the "try" clause. [2] Exceptions in the "else" clause are\nnot handled by the preceding "except" clauses.\n\nIf "finally" is present, it specifies a \'cleanup\' handler. The "try"\nclause is executed, including any "except" and "else" clauses. If an\nexception occurs in any of the clauses and is not handled, the\nexception is temporarily saved. The "finally" clause is executed. If\nthere is a saved exception it is re-raised at the end of the "finally"\nclause. If the "finally" clause raises another exception, the saved\nexception is set as the context of the new exception. If the "finally"\nclause executes a "return" or "break" statement, the saved exception\nis discarded:\n\n >>> def f():\n ... try:\n ... 1/0\n ... finally:\n ... return 42\n ...\n >>> f()\n 42\n\nThe exception information is not available to the program during\nexecution of the "finally" clause.\n\nWhen a "return", "break" or "continue" statement is executed in the\n"try" suite of a "try"..."finally" statement, the "finally" clause is\nalso executed \'on the way out.\' A "continue" statement is illegal in\nthe "finally" clause. (The reason is a problem with the current\nimplementation --- this restriction may be lifted in the future).\n\nThe return value of a function is determined by the last "return"\nstatement executed. Since the "finally" clause always executes, a\n"return" statement executed in the "finally" clause will always be the\nlast one executed:\n\n >>> def foo():\n ... try:\n ... return \'try\'\n ... finally:\n ... return \'finally\'\n ...\n >>> foo()\n \'finally\'\n\nAdditional information on exceptions can be found in section\n*Exceptions*, and information on using the "raise" statement to\ngenerate exceptions may be found in section *The raise statement*.\n', + 'try': '\nThe "try" statement\n*******************\n\nThe "try" statement specifies exception handlers and/or cleanup code\nfor a group of statements:\n\n try_stmt ::= try1_stmt | try2_stmt\n try1_stmt ::= "try" ":" suite\n ("except" [expression ["as" target]] ":" suite)+\n ["else" ":" suite]\n ["finally" ":" suite]\n try2_stmt ::= "try" ":" suite\n "finally" ":" suite\n\nThe "except" clause(s) specify one or more exception handlers. When no\nexception occurs in the "try" clause, no exception handler is\nexecuted. When an exception occurs in the "try" suite, a search for an\nexception handler is started. This search inspects the except clauses\nin turn until one is found that matches the exception. An expression-\nless except clause, if present, must be last; it matches any\nexception. For an except clause with an expression, that expression\nis evaluated, and the clause matches the exception if the resulting\nobject is "compatible" with the exception. An object is compatible\nwith an exception if it is the class or a base class of the exception\nobject or a tuple containing an item compatible with the exception.\n\nIf no except clause matches the exception, the search for an exception\nhandler continues in the surrounding code and on the invocation stack.\n[1]\n\nIf the evaluation of an expression in the header of an except clause\nraises an exception, the original search for a handler is canceled and\na search starts for the new exception in the surrounding code and on\nthe call stack (it is treated as if the entire "try" statement raised\nthe exception).\n\nWhen a matching except clause is found, the exception is assigned to\nthe target specified after the "as" keyword in that except clause, if\npresent, and the except clause\'s suite is executed. All except\nclauses must have an executable block. When the end of this block is\nreached, execution continues normally after the entire try statement.\n(This means that if two nested handlers exist for the same exception,\nand the exception occurs in the try clause of the inner handler, the\nouter handler will not handle the exception.)\n\nWhen an exception has been assigned using "as target", it is cleared\nat the end of the except clause. This is as if\n\n except E as N:\n foo\n\nwas translated to\n\n except E as N:\n try:\n foo\n finally:\n del N\n\nThis means the exception must be assigned to a different name to be\nable to refer to it after the except clause. Exceptions are cleared\nbecause with the traceback attached to them, they form a reference\ncycle with the stack frame, keeping all locals in that frame alive\nuntil the next garbage collection occurs.\n\nBefore an except clause\'s suite is executed, details about the\nexception are stored in the "sys" module and can be access via\n"sys.exc_info()". "sys.exc_info()" returns a 3-tuple consisting of the\nexception class, the exception instance and a traceback object (see\nsection *The standard type hierarchy*) identifying the point in the\nprogram where the exception occurred. "sys.exc_info()" values are\nrestored to their previous values (before the call) when returning\nfrom a function that handled an exception.\n\nThe optional "else" clause is executed if and when control flows off\nthe end of the "try" clause. [2] Exceptions in the "else" clause are\nnot handled by the preceding "except" clauses.\n\nIf "finally" is present, it specifies a \'cleanup\' handler. The "try"\nclause is executed, including any "except" and "else" clauses. If an\nexception occurs in any of the clauses and is not handled, the\nexception is temporarily saved. The "finally" clause is executed. If\nthere is a saved exception it is re-raised at the end of the "finally"\nclause. If the "finally" clause raises another exception, the saved\nexception is set as the context of the new exception. If the "finally"\nclause executes a "return" or "break" statement, the saved exception\nis discarded:\n\n def f():\n try:\n 1/0\n finally:\n return 42\n\n >>> f()\n 42\n\nThe exception information is not available to the program during\nexecution of the "finally" clause.\n\nWhen a "return", "break" or "continue" statement is executed in the\n"try" suite of a "try"..."finally" statement, the "finally" clause is\nalso executed \'on the way out.\' A "continue" statement is illegal in\nthe "finally" clause. (The reason is a problem with the current\nimplementation --- this restriction may be lifted in the future).\n\nAdditional information on exceptions can be found in section\n*Exceptions*, and information on using the "raise" statement to\ngenerate exceptions may be found in section *The raise statement*.\n', 'types': '\nThe standard type hierarchy\n***************************\n\nBelow is a list of the types that are built into Python. Extension\nmodules (written in C, Java, or other languages, depending on the\nimplementation) can define additional types. Future versions of\nPython may add types to the type hierarchy (e.g., rational numbers,\nefficiently stored arrays of integers, etc.), although such additions\nwill often be provided via the standard library instead.\n\nSome of the type descriptions below contain a paragraph listing\n\'special attributes.\' These are attributes that provide access to the\nimplementation and are not intended for general use. Their definition\nmay change in the future.\n\nNone\n This type has a single value. There is a single object with this\n value. This object is accessed through the built-in name "None". It\n is used to signify the absence of a value in many situations, e.g.,\n it is returned from functions that don\'t explicitly return\n anything. Its truth value is false.\n\nNotImplemented\n This type has a single value. There is a single object with this\n value. This object is accessed through the built-in name\n "NotImplemented". Numeric methods and rich comparison methods may\n return this value if they do not implement the operation for the\n operands provided. (The interpreter will then try the reflected\n operation, or some other fallback, depending on the operator.) Its\n truth value is true.\n\nEllipsis\n This type has a single value. There is a single object with this\n value. This object is accessed through the literal "..." or the\n built-in name "Ellipsis". Its truth value is true.\n\n"numbers.Number"\n These are created by numeric literals and returned as results by\n arithmetic operators and arithmetic built-in functions. Numeric\n objects are immutable; once created their value never changes.\n Python numbers are of course strongly related to mathematical\n numbers, but subject to the limitations of numerical representation\n in computers.\n\n Python distinguishes between integers, floating point numbers, and\n complex numbers:\n\n "numbers.Integral"\n These represent elements from the mathematical set of integers\n (positive and negative).\n\n There are two types of integers:\n\n Integers ("int")\n\n These represent numbers in an unlimited range, subject to\n available (virtual) memory only. For the purpose of shift\n and mask operations, a binary representation is assumed, and\n negative numbers are represented in a variant of 2\'s\n complement which gives the illusion of an infinite string of\n sign bits extending to the left.\n\n Booleans ("bool")\n These represent the truth values False and True. The two\n objects representing the values "False" and "True" are the\n only Boolean objects. The Boolean type is a subtype of the\n integer type, and Boolean values behave like the values 0 and\n 1, respectively, in almost all contexts, the exception being\n that when converted to a string, the strings ""False"" or\n ""True"" are returned, respectively.\n\n The rules for integer representation are intended to give the\n most meaningful interpretation of shift and mask operations\n involving negative integers.\n\n "numbers.Real" ("float")\n These represent machine-level double precision floating point\n numbers. You are at the mercy of the underlying machine\n architecture (and C or Java implementation) for the accepted\n range and handling of overflow. Python does not support single-\n precision floating point numbers; the savings in processor and\n memory usage that are usually the reason for using these is\n dwarfed by the overhead of using objects in Python, so there is\n no reason to complicate the language with two kinds of floating\n point numbers.\n\n "numbers.Complex" ("complex")\n These represent complex numbers as a pair of machine-level\n double precision floating point numbers. The same caveats apply\n as for floating point numbers. The real and imaginary parts of a\n complex number "z" can be retrieved through the read-only\n attributes "z.real" and "z.imag".\n\nSequences\n These represent finite ordered sets indexed by non-negative\n numbers. The built-in function "len()" returns the number of items\n of a sequence. When the length of a sequence is *n*, the index set\n contains the numbers 0, 1, ..., *n*-1. Item *i* of sequence *a* is\n selected by "a[i]".\n\n Sequences also support slicing: "a[i:j]" selects all items with\n index *k* such that *i* "<=" *k* "<" *j*. When used as an\n expression, a slice is a sequence of the same type. This implies\n that the index set is renumbered so that it starts at 0.\n\n Some sequences also support "extended slicing" with a third "step"\n parameter: "a[i:j:k]" selects all items of *a* with index *x* where\n "x = i + n*k", *n* ">=" "0" and *i* "<=" *x* "<" *j*.\n\n Sequences are distinguished according to their mutability:\n\n Immutable sequences\n An object of an immutable sequence type cannot change once it is\n created. (If the object contains references to other objects,\n these other objects may be mutable and may be changed; however,\n the collection of objects directly referenced by an immutable\n object cannot change.)\n\n The following types are immutable sequences:\n\n Strings\n A string is a sequence of values that represent Unicode\n codepoints. All the codepoints in range "U+0000 - U+10FFFF"\n can be represented in a string. Python doesn\'t have a "chr"\n type, and every character in the string is represented as a\n string object with length "1". The built-in function "ord()"\n converts a character to its codepoint (as an integer);\n "chr()" converts an integer in range "0 - 10FFFF" to the\n corresponding character. "str.encode()" can be used to\n convert a "str" to "bytes" using the given encoding, and\n "bytes.decode()" can be used to achieve the opposite.\n\n Tuples\n The items of a tuple are arbitrary Python objects. Tuples of\n two or more items are formed by comma-separated lists of\n expressions. A tuple of one item (a \'singleton\') can be\n formed by affixing a comma to an expression (an expression by\n itself does not create a tuple, since parentheses must be\n usable for grouping of expressions). An empty tuple can be\n formed by an empty pair of parentheses.\n\n Bytes\n A bytes object is an immutable array. The items are 8-bit\n bytes, represented by integers in the range 0 <= x < 256.\n Bytes literals (like "b\'abc\'") and the built-in function\n "bytes()" can be used to construct bytes objects. Also,\n bytes objects can be decoded to strings via the "decode()"\n method.\n\n Mutable sequences\n Mutable sequences can be changed after they are created. The\n subscription and slicing notations can be used as the target of\n assignment and "del" (delete) statements.\n\n There are currently two intrinsic mutable sequence types:\n\n Lists\n The items of a list are arbitrary Python objects. Lists are\n formed by placing a comma-separated list of expressions in\n square brackets. (Note that there are no special cases needed\n to form lists of length 0 or 1.)\n\n Byte Arrays\n A bytearray object is a mutable array. They are created by\n the built-in "bytearray()" constructor. Aside from being\n mutable (and hence unhashable), byte arrays otherwise provide\n the same interface and functionality as immutable bytes\n objects.\n\n The extension module "array" provides an additional example of a\n mutable sequence type, as does the "collections" module.\n\nSet types\n These represent unordered, finite sets of unique, immutable\n objects. As such, they cannot be indexed by any subscript. However,\n they can be iterated over, and the built-in function "len()"\n returns the number of items in a set. Common uses for sets are fast\n membership testing, removing duplicates from a sequence, and\n computing mathematical operations such as intersection, union,\n difference, and symmetric difference.\n\n For set elements, the same immutability rules apply as for\n dictionary keys. Note that numeric types obey the normal rules for\n numeric comparison: if two numbers compare equal (e.g., "1" and\n "1.0"), only one of them can be contained in a set.\n\n There are currently two intrinsic set types:\n\n Sets\n These represent a mutable set. They are created by the built-in\n "set()" constructor and can be modified afterwards by several\n methods, such as "add()".\n\n Frozen sets\n These represent an immutable set. They are created by the\n built-in "frozenset()" constructor. As a frozenset is immutable\n and *hashable*, it can be used again as an element of another\n set, or as a dictionary key.\n\nMappings\n These represent finite sets of objects indexed by arbitrary index\n sets. The subscript notation "a[k]" selects the item indexed by "k"\n from the mapping "a"; this can be used in expressions and as the\n target of assignments or "del" statements. The built-in function\n "len()" returns the number of items in a mapping.\n\n There is currently a single intrinsic mapping type:\n\n Dictionaries\n These represent finite sets of objects indexed by nearly\n arbitrary values. The only types of values not acceptable as\n keys are values containing lists or dictionaries or other\n mutable types that are compared by value rather than by object\n identity, the reason being that the efficient implementation of\n dictionaries requires a key\'s hash value to remain constant.\n Numeric types used for keys obey the normal rules for numeric\n comparison: if two numbers compare equal (e.g., "1" and "1.0")\n then they can be used interchangeably to index the same\n dictionary entry.\n\n Dictionaries are mutable; they can be created by the "{...}"\n notation (see section *Dictionary displays*).\n\n The extension modules "dbm.ndbm" and "dbm.gnu" provide\n additional examples of mapping types, as does the "collections"\n module.\n\nCallable types\n These are the types to which the function call operation (see\n section *Calls*) can be applied:\n\n User-defined functions\n A user-defined function object is created by a function\n definition (see section *Function definitions*). It should be\n called with an argument list containing the same number of items\n as the function\'s formal parameter list.\n\n Special attributes:\n\n +---------------------------+---------------------------------+-------------+\n +===========================+=================================+=============+\n | "__doc__" | The function\'s documentation | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__name__" | The function\'s name | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__qualname__" | The function\'s *qualified name* | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__module__" | The name of the module the | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__defaults__" | A tuple containing default | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__code__" | The code object representing | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__globals__" | A reference to the dictionary | Read-only |\n +---------------------------+---------------------------------+-------------+\n | "__dict__" | The namespace supporting | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__closure__" | "None" or a tuple of cells that | Read-only |\n +---------------------------+---------------------------------+-------------+\n | "__annotations__" | A dict containing annotations | Writable |\n +---------------------------+---------------------------------+-------------+\n | "__kwdefaults__" | A dict containing defaults for | Writable |\n +---------------------------+---------------------------------+-------------+\n\n Most of the attributes labelled "Writable" check the type of the\n assigned value.\n\n Function objects also support getting and setting arbitrary\n attributes, which can be used, for example, to attach metadata\n to functions. Regular attribute dot-notation is used to get and\n set such attributes. *Note that the current implementation only\n supports function attributes on user-defined functions. Function\n attributes on built-in functions may be supported in the\n future.*\n\n Additional information about a function\'s definition can be\n retrieved from its code object; see the description of internal\n types below.\n\n Instance methods\n An instance method object combines a class, a class instance and\n any callable object (normally a user-defined function).\n\n Special read-only attributes: "__self__" is the class instance\n object, "__func__" is the function object; "__doc__" is the\n method\'s documentation (same as "__func__.__doc__"); "__name__"\n is the method name (same as "__func__.__name__"); "__module__"\n is the name of the module the method was defined in, or "None"\n if unavailable.\n\n Methods also support accessing (but not setting) the arbitrary\n function attributes on the underlying function object.\n\n User-defined method objects may be created when getting an\n attribute of a class (perhaps via an instance of that class), if\n that attribute is a user-defined function object or a class\n method object.\n\n When an instance method object is created by retrieving a user-\n defined function object from a class via one of its instances,\n its "__self__" attribute is the instance, and the method object\n is said to be bound. The new method\'s "__func__" attribute is\n the original function object.\n\n When a user-defined method object is created by retrieving\n another method object from a class or instance, the behaviour is\n the same as for a function object, except that the "__func__"\n attribute of the new instance is not the original method object\n but its "__func__" attribute.\n\n When an instance method object is created by retrieving a class\n method object from a class or instance, its "__self__" attribute\n is the class itself, and its "__func__" attribute is the\n function object underlying the class method.\n\n When an instance method object is called, the underlying\n function ("__func__") is called, inserting the class instance\n ("__self__") in front of the argument list. For instance, when\n "C" is a class which contains a definition for a function "f()",\n and "x" is an instance of "C", calling "x.f(1)" is equivalent to\n calling "C.f(x, 1)".\n\n When an instance method object is derived from a class method\n object, the "class instance" stored in "__self__" will actually\n be the class itself, so that calling either "x.f(1)" or "C.f(1)"\n is equivalent to calling "f(C,1)" where "f" is the underlying\n function.\n\n Note that the transformation from function object to instance\n method object happens each time the attribute is retrieved from\n the instance. In some cases, a fruitful optimization is to\n assign the attribute to a local variable and call that local\n variable. Also notice that this transformation only happens for\n user-defined functions; other callable objects (and all non-\n callable objects) are retrieved without transformation. It is\n also important to note that user-defined functions which are\n attributes of a class instance are not converted to bound\n methods; this *only* happens when the function is an attribute\n of the class.\n\n Generator functions\n A function or method which uses the "yield" statement (see\n section *The yield statement*) is called a *generator function*.\n Such a function, when called, always returns an iterator object\n which can be used to execute the body of the function: calling\n the iterator\'s "iterator.__next__()" method will cause the\n function to execute until it provides a value using the "yield"\n statement. When the function executes a "return" statement or\n falls off the end, a "StopIteration" exception is raised and the\n iterator will have reached the end of the set of values to be\n returned.\n\n Built-in functions\n A built-in function object is a wrapper around a C function.\n Examples of built-in functions are "len()" and "math.sin()"\n ("math" is a standard built-in module). The number and type of\n the arguments are determined by the C function. Special read-\n only attributes: "__doc__" is the function\'s documentation\n string, or "None" if unavailable; "__name__" is the function\'s\n name; "__self__" is set to "None" (but see the next item);\n "__module__" is the name of the module the function was defined\n in or "None" if unavailable.\n\n Built-in methods\n This is really a different disguise of a built-in function, this\n time containing an object passed to the C function as an\n implicit extra argument. An example of a built-in method is\n "alist.append()", assuming *alist* is a list object. In this\n case, the special read-only attribute "__self__" is set to the\n object denoted by *alist*.\n\n Classes\n Classes are callable. These objects normally act as factories\n for new instances of themselves, but variations are possible for\n class types that override "__new__()". The arguments of the\n call are passed to "__new__()" and, in the typical case, to\n "__init__()" to initialize the new instance.\n\n Class Instances\n Instances of arbitrary classes can be made callable by defining\n a "__call__()" method in their class.\n\nModules\n Modules are a basic organizational unit of Python code, and are\n created by the *import system* as invoked either by the "import"\n statement (see "import"), or by calling functions such as\n "importlib.import_module()" and built-in "__import__()". A module\n object has a namespace implemented by a dictionary object (this is\n the dictionary referenced by the "__globals__" attribute of\n functions defined in the module). Attribute references are\n translated to lookups in this dictionary, e.g., "m.x" is equivalent\n to "m.__dict__["x"]". A module object does not contain the code\n object used to initialize the module (since it isn\'t needed once\n the initialization is done).\n\n Attribute assignment updates the module\'s namespace dictionary,\n e.g., "m.x = 1" is equivalent to "m.__dict__["x"] = 1".\n\n Special read-only attribute: "__dict__" is the module\'s namespace\n as a dictionary object.\n\n **CPython implementation detail:** Because of the way CPython\n clears module dictionaries, the module dictionary will be cleared\n when the module falls out of scope even if the dictionary still has\n live references. To avoid this, copy the dictionary or keep the\n module around while using its dictionary directly.\n\n Predefined (writable) attributes: "__name__" is the module\'s name;\n "__doc__" is the module\'s documentation string, or "None" if\n unavailable; "__file__" is the pathname of the file from which the\n module was loaded, if it was loaded from a file. The "__file__"\n attribute may be missing for certain types of modules, such as C\n modules that are statically linked into the interpreter; for\n extension modules loaded dynamically from a shared library, it is\n the pathname of the shared library file.\n\nCustom classes\n Custom class types are typically created by class definitions (see\n section *Class definitions*). A class has a namespace implemented\n by a dictionary object. Class attribute references are translated\n to lookups in this dictionary, e.g., "C.x" is translated to\n "C.__dict__["x"]" (although there are a number of hooks which allow\n for other means of locating attributes). When the attribute name is\n not found there, the attribute search continues in the base\n classes. This search of the base classes uses the C3 method\n resolution order which behaves correctly even in the presence of\n \'diamond\' inheritance structures where there are multiple\n inheritance paths leading back to a common ancestor. Additional\n details on the C3 MRO used by Python can be found in the\n documentation accompanying the 2.3 release at\n http://www.python.org/download/releases/2.3/mro/.\n\n When a class attribute reference (for class "C", say) would yield a\n class method object, it is transformed into an instance method\n object whose "__self__" attributes is "C". When it would yield a\n static method object, it is transformed into the object wrapped by\n the static method object. See section *Implementing Descriptors*\n for another way in which attributes retrieved from a class may\n differ from those actually contained in its "__dict__".\n\n Class attribute assignments update the class\'s dictionary, never\n the dictionary of a base class.\n\n A class object can be called (see above) to yield a class instance\n (see below).\n\n Special attributes: "__name__" is the class name; "__module__" is\n the module name in which the class was defined; "__dict__" is the\n dictionary containing the class\'s namespace; "__bases__" is a tuple\n (possibly empty or a singleton) containing the base classes, in the\n order of their occurrence in the base class list; "__doc__" is the\n class\'s documentation string, or None if undefined.\n\nClass instances\n A class instance is created by calling a class object (see above).\n A class instance has a namespace implemented as a dictionary which\n is the first place in which attribute references are searched.\n When an attribute is not found there, and the instance\'s class has\n an attribute by that name, the search continues with the class\n attributes. If a class attribute is found that is a user-defined\n function object, it is transformed into an instance method object\n whose "__self__" attribute is the instance. Static method and\n class method objects are also transformed; see above under\n "Classes". See section *Implementing Descriptors* for another way\n in which attributes of a class retrieved via its instances may\n differ from the objects actually stored in the class\'s "__dict__".\n If no class attribute is found, and the object\'s class has a\n "__getattr__()" method, that is called to satisfy the lookup.\n\n Attribute assignments and deletions update the instance\'s\n dictionary, never a class\'s dictionary. If the class has a\n "__setattr__()" or "__delattr__()" method, this is called instead\n of updating the instance dictionary directly.\n\n Class instances can pretend to be numbers, sequences, or mappings\n if they have methods with certain special names. See section\n *Special method names*.\n\n Special attributes: "__dict__" is the attribute dictionary;\n "__class__" is the instance\'s class.\n\nI/O objects (also known as file objects)\n A *file object* represents an open file. Various shortcuts are\n available to create file objects: the "open()" built-in function,\n and also "os.popen()", "os.fdopen()", and the "makefile()" method\n of socket objects (and perhaps by other functions or methods\n provided by extension modules).\n\n The objects "sys.stdin", "sys.stdout" and "sys.stderr" are\n initialized to file objects corresponding to the interpreter\'s\n standard input, output and error streams; they are all open in text\n mode and therefore follow the interface defined by the\n "io.TextIOBase" abstract class.\n\nInternal types\n A few types used internally by the interpreter are exposed to the\n user. Their definitions may change with future versions of the\n interpreter, but they are mentioned here for completeness.\n\n Code objects\n Code objects represent *byte-compiled* executable Python code,\n or *bytecode*. The difference between a code object and a\n function object is that the function object contains an explicit\n reference to the function\'s globals (the module in which it was\n defined), while a code object contains no context; also the\n default argument values are stored in the function object, not\n in the code object (because they represent values calculated at\n run-time). Unlike function objects, code objects are immutable\n and contain no references (directly or indirectly) to mutable\n objects.\n\n Special read-only attributes: "co_name" gives the function name;\n "co_argcount" is the number of positional arguments (including\n arguments with default values); "co_nlocals" is the number of\n local variables used by the function (including arguments);\n "co_varnames" is a tuple containing the names of the local\n variables (starting with the argument names); "co_cellvars" is a\n tuple containing the names of local variables that are\n referenced by nested functions; "co_freevars" is a tuple\n containing the names of free variables; "co_code" is a string\n representing the sequence of bytecode instructions; "co_consts"\n is a tuple containing the literals used by the bytecode;\n "co_names" is a tuple containing the names used by the bytecode;\n "co_filename" is the filename from which the code was compiled;\n "co_firstlineno" is the first line number of the function;\n "co_lnotab" is a string encoding the mapping from bytecode\n offsets to line numbers (for details see the source code of the\n interpreter); "co_stacksize" is the required stack size\n (including local variables); "co_flags" is an integer encoding a\n number of flags for the interpreter.\n\n The following flag bits are defined for "co_flags": bit "0x04"\n is set if the function uses the "*arguments" syntax to accept an\n arbitrary number of positional arguments; bit "0x08" is set if\n the function uses the "**keywords" syntax to accept arbitrary\n keyword arguments; bit "0x20" is set if the function is a\n generator.\n\n Future feature declarations ("from __future__ import division")\n also use bits in "co_flags" to indicate whether a code object\n was compiled with a particular feature enabled: bit "0x2000" is\n set if the function was compiled with future division enabled;\n bits "0x10" and "0x1000" were used in earlier versions of\n Python.\n\n Other bits in "co_flags" are reserved for internal use.\n\n If a code object represents a function, the first item in\n "co_consts" is the documentation string of the function, or\n "None" if undefined.\n\n Frame objects\n Frame objects represent execution frames. They may occur in\n traceback objects (see below).\n\n Special read-only attributes: "f_back" is to the previous stack\n frame (towards the caller), or "None" if this is the bottom\n stack frame; "f_code" is the code object being executed in this\n frame; "f_locals" is the dictionary used to look up local\n variables; "f_globals" is used for global variables;\n "f_builtins" is used for built-in (intrinsic) names; "f_lasti"\n gives the precise instruction (this is an index into the\n bytecode string of the code object).\n\n Special writable attributes: "f_trace", if not "None", is a\n function called at the start of each source code line (this is\n used by the debugger); "f_lineno" is the current line number of\n the frame --- writing to this from within a trace function jumps\n to the given line (only for the bottom-most frame). A debugger\n can implement a Jump command (aka Set Next Statement) by writing\n to f_lineno.\n\n Frame objects support one method:\n\n frame.clear()\n\n This method clears all references to local variables held by\n the frame. Also, if the frame belonged to a generator, the\n generator is finalized. This helps break reference cycles\n involving frame objects (for example when catching an\n exception and storing its traceback for later use).\n\n "RuntimeError" is raised if the frame is currently executing.\n\n New in version 3.4.\n\n Traceback objects\n Traceback objects represent a stack trace of an exception. A\n traceback object is created when an exception occurs. When the\n search for an exception handler unwinds the execution stack, at\n each unwound level a traceback object is inserted in front of\n the current traceback. When an exception handler is entered,\n the stack trace is made available to the program. (See section\n *The try statement*.) It is accessible as the third item of the\n tuple returned by "sys.exc_info()". When the program contains no\n suitable handler, the stack trace is written (nicely formatted)\n to the standard error stream; if the interpreter is interactive,\n it is also made available to the user as "sys.last_traceback".\n\n Special read-only attributes: "tb_next" is the next level in the\n stack trace (towards the frame where the exception occurred), or\n "None" if there is no next level; "tb_frame" points to the\n execution frame of the current level; "tb_lineno" gives the line\n number where the exception occurred; "tb_lasti" indicates the\n precise instruction. The line number and last instruction in\n the traceback may differ from the line number of its frame\n object if the exception occurred in a "try" statement with no\n matching except clause or with a finally clause.\n\n Slice objects\n Slice objects are used to represent slices for "__getitem__()"\n methods. They are also created by the built-in "slice()"\n function.\n\n Special read-only attributes: "start" is the lower bound; "stop"\n is the upper bound; "step" is the step value; each is "None" if\n omitted. These attributes can have any type.\n\n Slice objects support one method:\n\n slice.indices(self, length)\n\n This method takes a single integer argument *length* and\n computes information about the slice that the slice object\n would describe if applied to a sequence of *length* items.\n It returns a tuple of three integers; respectively these are\n the *start* and *stop* indices and the *step* or stride\n length of the slice. Missing or out-of-bounds indices are\n handled in a manner consistent with regular slices.\n\n Static method objects\n Static method objects provide a way of defeating the\n transformation of function objects to method objects described\n above. A static method object is a wrapper around any other\n object, usually a user-defined method object. When a static\n method object is retrieved from a class or a class instance, the\n object actually returned is the wrapped object, which is not\n subject to any further transformation. Static method objects are\n not themselves callable, although the objects they wrap usually\n are. Static method objects are created by the built-in\n "staticmethod()" constructor.\n\n Class method objects\n A class method object, like a static method object, is a wrapper\n around another object that alters the way in which that object\n is retrieved from classes and class instances. The behaviour of\n class method objects upon such retrieval is described above,\n under "User-defined methods". Class method objects are created\n by the built-in "classmethod()" constructor.\n', 'typesfunctions': '\nFunctions\n*********\n\nFunction objects are created by function definitions. The only\noperation on a function object is to call it: "func(argument-list)".\n\nThere are really two flavors of function objects: built-in functions\nand user-defined functions. Both support the same operation (to call\nthe function), but the implementation is different, hence the\ndifferent object types.\n\nSee *Function definitions* for more information.\n', - 'typesmapping': '\nMapping Types --- "dict"\n************************\n\nA *mapping* object maps *hashable* values to arbitrary objects.\nMappings are mutable objects. There is currently only one standard\nmapping type, the *dictionary*. (For other containers see the built-\nin "list", "set", and "tuple" classes, and the "collections" module.)\n\nA dictionary\'s keys are *almost* arbitrary values. Values that are\nnot *hashable*, that is, values containing lists, dictionaries or\nother mutable types (that are compared by value rather than by object\nidentity) may not be used as keys. Numeric types used for keys obey\nthe normal rules for numeric comparison: if two numbers compare equal\n(such as "1" and "1.0") then they can be used interchangeably to index\nthe same dictionary entry. (Note however, that since computers store\nfloating-point numbers as approximations it is usually unwise to use\nthem as dictionary keys.)\n\nDictionaries can be created by placing a comma-separated list of "key:\nvalue" pairs within braces, for example: "{\'jack\': 4098, \'sjoerd\':\n4127}" or "{4098: \'jack\', 4127: \'sjoerd\'}", or by the "dict"\nconstructor.\n\nclass class dict(**kwarg)\nclass class dict(mapping, **kwarg)\nclass class dict(iterable, **kwarg)\n\n Return a new dictionary initialized from an optional positional\n argument and a possibly empty set of keyword arguments.\n\n If no positional argument is given, an empty dictionary is created.\n If a positional argument is given and it is a mapping object, a\n dictionary is created with the same key-value pairs as the mapping\n object. Otherwise, the positional argument must be an *iterator*\n object. Each item in the iterable must itself be an iterator with\n exactly two objects. The first object of each item becomes a key\n in the new dictionary, and the second object the corresponding\n value. If a key occurs more than once, the last value for that key\n becomes the corresponding value in the new dictionary.\n\n If keyword arguments are given, the keyword arguments and their\n values are added to the dictionary created from the positional\n argument. If a key being added is already present, the value from\n the keyword argument replaces the value from the positional\n argument.\n\n To illustrate, the following examples all return a dictionary equal\n to "{"one": 1, "two": 2, "three": 3}":\n\n >>> a = dict(one=1, two=2, three=3)\n >>> b = {\'one\': 1, \'two\': 2, \'three\': 3}\n >>> c = dict(zip([\'one\', \'two\', \'three\'], [1, 2, 3]))\n >>> d = dict([(\'two\', 2), (\'one\', 1), (\'three\', 3)])\n >>> e = dict({\'three\': 3, \'one\': 1, \'two\': 2})\n >>> a == b == c == d == e\n True\n\n Providing keyword arguments as in the first example only works for\n keys that are valid Python identifiers. Otherwise, any valid keys\n can be used.\n\n These are the operations that dictionaries support (and therefore,\n custom mapping types should support too):\n\n len(d)\n\n Return the number of items in the dictionary *d*.\n\n d[key]\n\n Return the item of *d* with key *key*. Raises a "KeyError" if\n *key* is not in the map.\n\n If a subclass of dict defines a method "__missing__()", if the\n key *key* is not present, the "d[key]" operation calls that\n method with the key *key* as argument. The "d[key]" operation\n then returns or raises whatever is returned or raised by the\n "__missing__(key)" call if the key is not present. No other\n operations or methods invoke "__missing__()". If "__missing__()"\n is not defined, "KeyError" is raised. "__missing__()" must be a\n method; it cannot be an instance variable:\n\n >>> class Counter(dict):\n ... def __missing__(self, key):\n ... return 0\n >>> c = Counter()\n >>> c[\'red\']\n 0\n >>> c[\'red\'] += 1\n >>> c[\'red\']\n 1\n\n See "collections.Counter" for a complete implementation\n including other methods helpful for accumulating and managing\n tallies.\n\n d[key] = value\n\n Set "d[key]" to *value*.\n\n del d[key]\n\n Remove "d[key]" from *d*. Raises a "KeyError" if *key* is not\n in the map.\n\n key in d\n\n Return "True" if *d* has a key *key*, else "False".\n\n key not in d\n\n Equivalent to "not key in d".\n\n iter(d)\n\n Return an iterator over the keys of the dictionary. This is a\n shortcut for "iter(d.keys())".\n\n clear()\n\n Remove all items from the dictionary.\n\n copy()\n\n Return a shallow copy of the dictionary.\n\n classmethod fromkeys(seq[, value])\n\n Create a new dictionary with keys from *seq* and values set to\n *value*.\n\n "fromkeys()" is a class method that returns a new dictionary.\n *value* defaults to "None".\n\n get(key[, default])\n\n Return the value for *key* if *key* is in the dictionary, else\n *default*. If *default* is not given, it defaults to "None", so\n that this method never raises a "KeyError".\n\n items()\n\n Return a new view of the dictionary\'s items ("(key, value)"\n pairs). See the *documentation of view objects*.\n\n keys()\n\n Return a new view of the dictionary\'s keys. See the\n *documentation of view objects*.\n\n pop(key[, default])\n\n If *key* is in the dictionary, remove it and return its value,\n else return *default*. If *default* is not given and *key* is\n not in the dictionary, a "KeyError" is raised.\n\n popitem()\n\n Remove and return an arbitrary "(key, value)" pair from the\n dictionary.\n\n "popitem()" is useful to destructively iterate over a\n dictionary, as often used in set algorithms. If the dictionary\n is empty, calling "popitem()" raises a "KeyError".\n\n setdefault(key[, default])\n\n If *key* is in the dictionary, return its value. If not, insert\n *key* with a value of *default* and return *default*. *default*\n defaults to "None".\n\n update([other])\n\n Update the dictionary with the key/value pairs from *other*,\n overwriting existing keys. Return "None".\n\n "update()" accepts either another dictionary object or an\n iterable of key/value pairs (as tuples or other iterables of\n length two). If keyword arguments are specified, the dictionary\n is then updated with those key/value pairs: "d.update(red=1,\n blue=2)".\n\n values()\n\n Return a new view of the dictionary\'s values. See the\n *documentation of view objects*.\n\nSee also:\n\n "types.MappingProxyType" can be used to create a read-only view of\n a "dict".\n\n\nDictionary view objects\n=======================\n\nThe objects returned by "dict.keys()", "dict.values()" and\n"dict.items()" are *view objects*. They provide a dynamic view on the\ndictionary\'s entries, which means that when the dictionary changes,\nthe view reflects these changes.\n\nDictionary views can be iterated over to yield their respective data,\nand support membership tests:\n\nlen(dictview)\n\n Return the number of entries in the dictionary.\n\niter(dictview)\n\n Return an iterator over the keys, values or items (represented as\n tuples of "(key, value)") in the dictionary.\n\n Keys and values are iterated over in an arbitrary order which is\n non-random, varies across Python implementations, and depends on\n the dictionary\'s history of insertions and deletions. If keys,\n values and items views are iterated over with no intervening\n modifications to the dictionary, the order of items will directly\n correspond. This allows the creation of "(value, key)" pairs using\n "zip()": "pairs = zip(d.values(), d.keys())". Another way to\n create the same list is "pairs = [(v, k) for (k, v) in d.items()]".\n\n Iterating views while adding or deleting entries in the dictionary\n may raise a "RuntimeError" or fail to iterate over all entries.\n\nx in dictview\n\n Return "True" if *x* is in the underlying dictionary\'s keys, values\n or items (in the latter case, *x* should be a "(key, value)"\n tuple).\n\nKeys views are set-like since their entries are unique and hashable.\nIf all values are hashable, so that "(key, value)" pairs are unique\nand hashable, then the items view is also set-like. (Values views are\nnot treated as set-like since the entries are generally not unique.)\nFor set-like views, all of the operations defined for the abstract\nbase class "collections.abc.Set" are available (for example, "==",\n"<", or "^").\n\nAn example of dictionary view usage:\n\n >>> dishes = {\'eggs\': 2, \'sausage\': 1, \'bacon\': 1, \'spam\': 500}\n >>> keys = dishes.keys()\n >>> values = dishes.values()\n\n >>> # iteration\n >>> n = 0\n >>> for val in values:\n ... n += val\n >>> print(n)\n 504\n\n >>> # keys and values are iterated over in the same order\n >>> list(keys)\n [\'eggs\', \'bacon\', \'sausage\', \'spam\']\n >>> list(values)\n [2, 1, 1, 500]\n\n >>> # view objects are dynamic and reflect dict changes\n >>> del dishes[\'eggs\']\n >>> del dishes[\'sausage\']\n >>> list(keys)\n [\'spam\', \'bacon\']\n\n >>> # set operations\n >>> keys & {\'eggs\', \'bacon\', \'salad\'}\n {\'bacon\'}\n >>> keys ^ {\'sausage\', \'juice\'}\n {\'juice\', \'sausage\', \'bacon\', \'spam\'}\n', + 'typesmapping': '\nMapping Types --- "dict"\n************************\n\nA *mapping* object maps *hashable* values to arbitrary objects.\nMappings are mutable objects. There is currently only one standard\nmapping type, the *dictionary*. (For other containers see the built-\nin "list", "set", and "tuple" classes, and the "collections" module.)\n\nA dictionary\'s keys are *almost* arbitrary values. Values that are\nnot *hashable*, that is, values containing lists, dictionaries or\nother mutable types (that are compared by value rather than by object\nidentity) may not be used as keys. Numeric types used for keys obey\nthe normal rules for numeric comparison: if two numbers compare equal\n(such as "1" and "1.0") then they can be used interchangeably to index\nthe same dictionary entry. (Note however, that since computers store\nfloating-point numbers as approximations it is usually unwise to use\nthem as dictionary keys.)\n\nDictionaries can be created by placing a comma-separated list of "key:\nvalue" pairs within braces, for example: "{\'jack\': 4098, \'sjoerd\':\n4127}" or "{4098: \'jack\', 4127: \'sjoerd\'}", or by the "dict"\nconstructor.\n\nclass class dict(**kwarg)\nclass class dict(mapping, **kwarg)\nclass class dict(iterable, **kwarg)\n\n Return a new dictionary initialized from an optional positional\n argument and a possibly empty set of keyword arguments.\n\n If no positional argument is given, an empty dictionary is created.\n If a positional argument is given and it is a mapping object, a\n dictionary is created with the same key-value pairs as the mapping\n object. Otherwise, the positional argument must be an *iterator*\n object. Each item in the iterable must itself be an iterator with\n exactly two objects. The first object of each item becomes a key\n in the new dictionary, and the second object the corresponding\n value. If a key occurs more than once, the last value for that key\n becomes the corresponding value in the new dictionary.\n\n If keyword arguments are given, the keyword arguments and their\n values are added to the dictionary created from the positional\n argument. If a key being added is already present, the value from\n the keyword argument replaces the value from the positional\n argument.\n\n To illustrate, the following examples all return a dictionary equal\n to "{"one": 1, "two": 2, "three": 3}":\n\n >>> a = dict(one=1, two=2, three=3)\n >>> b = {\'one\': 1, \'two\': 2, \'three\': 3}\n >>> c = dict(zip([\'one\', \'two\', \'three\'], [1, 2, 3]))\n >>> d = dict([(\'two\', 2), (\'one\', 1), (\'three\', 3)])\n >>> e = dict({\'three\': 3, \'one\': 1, \'two\': 2})\n >>> a == b == c == d == e\n True\n\n Providing keyword arguments as in the first example only works for\n keys that are valid Python identifiers. Otherwise, any valid keys\n can be used.\n\n These are the operations that dictionaries support (and therefore,\n custom mapping types should support too):\n\n len(d)\n\n Return the number of items in the dictionary *d*.\n\n d[key]\n\n Return the item of *d* with key *key*. Raises a "KeyError" if\n *key* is not in the map.\n\n If a subclass of dict defines a method "__missing__()", if the\n key *key* is not present, the "d[key]" operation calls that\n method with the key *key* as argument. The "d[key]" operation\n then returns or raises whatever is returned or raised by the\n "__missing__(key)" call if the key is not present. No other\n operations or methods invoke "__missing__()". If "__missing__()"\n is not defined, "KeyError" is raised. "__missing__()" must be a\n method; it cannot be an instance variable:\n\n >>> class Counter(dict):\n ... def __missing__(self, key):\n ... return 0\n >>> c = Counter()\n >>> c[\'red\']\n 0\n >>> c[\'red\'] += 1\n >>> c[\'red\']\n 1\n\n See "collections.Counter" for a complete implementation\n including other methods helpful for accumulating and managing\n tallies.\n\n d[key] = value\n\n Set "d[key]" to *value*.\n\n del d[key]\n\n Remove "d[key]" from *d*. Raises a "KeyError" if *key* is not\n in the map.\n\n key in d\n\n Return "True" if *d* has a key *key*, else "False".\n\n key not in d\n\n Equivalent to "not key in d".\n\n iter(d)\n\n Return an iterator over the keys of the dictionary. This is a\n shortcut for "iter(d.keys())".\n\n clear()\n\n Remove all items from the dictionary.\n\n copy()\n\n Return a shallow copy of the dictionary.\n\n classmethod fromkeys(seq[, value])\n\n Create a new dictionary with keys from *seq* and values set to\n *value*.\n\n "fromkeys()" is a class method that returns a new dictionary.\n *value* defaults to "None".\n\n get(key[, default])\n\n Return the value for *key* if *key* is in the dictionary, else\n *default*. If *default* is not given, it defaults to "None", so\n that this method never raises a "KeyError".\n\n items()\n\n Return a new view of the dictionary\'s items ("(key, value)"\n pairs). See the *documentation of view objects*.\n\n keys()\n\n Return a new view of the dictionary\'s keys. See the\n *documentation of view objects*.\n\n pop(key[, default])\n\n If *key* is in the dictionary, remove it and return its value,\n else return *default*. If *default* is not given and *key* is\n not in the dictionary, a "KeyError" is raised.\n\n popitem()\n\n Remove and return an arbitrary "(key, value)" pair from the\n dictionary.\n\n "popitem()" is useful to destructively iterate over a\n dictionary, as often used in set algorithms. If the dictionary\n is empty, calling "popitem()" raises a "KeyError".\n\n setdefault(key[, default])\n\n If *key* is in the dictionary, return its value. If not, insert\n *key* with a value of *default* and return *default*. *default*\n defaults to "None".\n\n update([other])\n\n Update the dictionary with the key/value pairs from *other*,\n overwriting existing keys. Return "None".\n\n "update()" accepts either another dictionary object or an\n iterable of key/value pairs (as tuples or other iterables of\n length two). If keyword arguments are specified, the dictionary\n is then updated with those key/value pairs: "d.update(red=1,\n blue=2)".\n\n values()\n\n Return a new view of the dictionary\'s values. See the\n *documentation of view objects*.\n\nSee also: "types.MappingProxyType" can be used to create a read-only\n view of a "dict".\n\n\nDictionary view objects\n=======================\n\nThe objects returned by "dict.keys()", "dict.values()" and\n"dict.items()" are *view objects*. They provide a dynamic view on the\ndictionary\'s entries, which means that when the dictionary changes,\nthe view reflects these changes.\n\nDictionary views can be iterated over to yield their respective data,\nand support membership tests:\n\nlen(dictview)\n\n Return the number of entries in the dictionary.\n\niter(dictview)\n\n Return an iterator over the keys, values or items (represented as\n tuples of "(key, value)") in the dictionary.\n\n Keys and values are iterated over in an arbitrary order which is\n non-random, varies across Python implementations, and depends on\n the dictionary\'s history of insertions and deletions. If keys,\n values and items views are iterated over with no intervening\n modifications to the dictionary, the order of items will directly\n correspond. This allows the creation of "(value, key)" pairs using\n "zip()": "pairs = zip(d.values(), d.keys())". Another way to\n create the same list is "pairs = [(v, k) for (k, v) in d.items()]".\n\n Iterating views while adding or deleting entries in the dictionary\n may raise a "RuntimeError" or fail to iterate over all entries.\n\nx in dictview\n\n Return "True" if *x* is in the underlying dictionary\'s keys, values\n or items (in the latter case, *x* should be a "(key, value)"\n tuple).\n\nKeys views are set-like since their entries are unique and hashable.\nIf all values are hashable, so that "(key, value)" pairs are unique\nand hashable, then the items view is also set-like. (Values views are\nnot treated as set-like since the entries are generally not unique.)\nFor set-like views, all of the operations defined for the abstract\nbase class "collections.abc.Set" are available (for example, "==",\n"<", or "^").\n\nAn example of dictionary view usage:\n\n >>> dishes = {\'eggs\': 2, \'sausage\': 1, \'bacon\': 1, \'spam\': 500}\n >>> keys = dishes.keys()\n >>> values = dishes.values()\n\n >>> # iteration\n >>> n = 0\n >>> for val in values:\n ... n += val\n >>> print(n)\n 504\n\n >>> # keys and values are iterated over in the same order\n >>> list(keys)\n [\'eggs\', \'bacon\', \'sausage\', \'spam\']\n >>> list(values)\n [2, 1, 1, 500]\n\n >>> # view objects are dynamic and reflect dict changes\n >>> del dishes[\'eggs\']\n >>> del dishes[\'sausage\']\n >>> list(keys)\n [\'spam\', \'bacon\']\n\n >>> # set operations\n >>> keys & {\'eggs\', \'bacon\', \'salad\'}\n {\'bacon\'}\n >>> keys ^ {\'sausage\', \'juice\'}\n {\'juice\', \'sausage\', \'bacon\', \'spam\'}\n', 'typesmethods': '\nMethods\n*******\n\nMethods are functions that are called using the attribute notation.\nThere are two flavors: built-in methods (such as "append()" on lists)\nand class instance methods. Built-in methods are described with the\ntypes that support them.\n\nIf you access a method (a function defined in a class namespace)\nthrough an instance, you get a special object: a *bound method* (also\ncalled *instance method*) object. When called, it will add the "self"\nargument to the argument list. Bound methods have two special read-\nonly attributes: "m.__self__" is the object on which the method\noperates, and "m.__func__" is the function implementing the method.\nCalling "m(arg-1, arg-2, ..., arg-n)" is completely equivalent to\ncalling "m.__func__(m.__self__, arg-1, arg-2, ..., arg-n)".\n\nLike function objects, bound method objects support getting arbitrary\nattributes. However, since method attributes are actually stored on\nthe underlying function object ("meth.__func__"), setting method\nattributes on bound methods is disallowed. Attempting to set an\nattribute on a method results in an "AttributeError" being raised. In\norder to set a method attribute, you need to explicitly set it on the\nunderlying function object:\n\n >>> class C:\n ... def method(self):\n ... pass\n ...\n >>> c = C()\n >>> c.method.whoami = \'my name is method\' # can\'t set on the method\n Traceback (most recent call last):\n File "<stdin>", line 1, in <module>\n AttributeError: \'method\' object has no attribute \'whoami\'\n >>> c.method.__func__.whoami = \'my name is method\'\n >>> c.method.whoami\n \'my name is method\'\n\nSee *The standard type hierarchy* for more information.\n', 'typesmodules': '\nModules\n*******\n\nThe only special operation on a module is attribute access: "m.name",\nwhere *m* is a module and *name* accesses a name defined in *m*\'s\nsymbol table. Module attributes can be assigned to. (Note that the\n"import" statement is not, strictly speaking, an operation on a module\nobject; "import foo" does not require a module object named *foo* to\nexist, rather it requires an (external) *definition* for a module\nnamed *foo* somewhere.)\n\nA special attribute of every module is "__dict__". This is the\ndictionary containing the module\'s symbol table. Modifying this\ndictionary will actually change the module\'s symbol table, but direct\nassignment to the "__dict__" attribute is not possible (you can write\n"m.__dict__[\'a\'] = 1", which defines "m.a" to be "1", but you can\'t\nwrite "m.__dict__ = {}"). Modifying "__dict__" directly is not\nrecommended.\n\nModules built into the interpreter are written like this: "<module\n\'sys\' (built-in)>". If loaded from a file, they are written as\n"<module \'os\' from \'/usr/local/lib/pythonX.Y/os.pyc\'>".\n', - 'typesseq': '\nSequence Types --- "list", "tuple", "range"\n*******************************************\n\nThere are three basic sequence types: lists, tuples, and range\nobjects. Additional sequence types tailored for processing of *binary\ndata* and *text strings* are described in dedicated sections.\n\n\nCommon Sequence Operations\n==========================\n\nThe operations in the following table are supported by most sequence\ntypes, both mutable and immutable. The "collections.abc.Sequence" ABC\nis provided to make it easier to correctly implement these operations\non custom sequence types.\n\nThis table lists the sequence operations sorted in ascending priority\n(operations in the same box have the same priority). In the table,\n*s* and *t* are sequences of the same type, *n*, *i*, *j* and *k* are\nintegers and *x* is an arbitrary object that meets any type and value\nrestrictions imposed by *s*.\n\nThe "in" and "not in" operations have the same priorities as the\ncomparison operations. The "+" (concatenation) and "*" (repetition)\noperations have the same priority as the corresponding numeric\noperations.\n\n+----------------------------+----------------------------------+------------+\n| Operation | Result | Notes |\n+============================+==================================+============+\n| "x in s" | "True" if an item of *s* is | (1) |\n+----------------------------+----------------------------------+------------+\n| "x not in s" | "False" if an item of *s* is | (1) |\n+----------------------------+----------------------------------+------------+\n| "s + t" | the concatenation of *s* and *t* | (6)(7) |\n+----------------------------+----------------------------------+------------+\n| "s * n" or "n * s" | *n* shallow copies of *s* | (2)(7) |\n+----------------------------+----------------------------------+------------+\n| "s[i]" | *i*th item of *s*, origin 0 | (3) |\n+----------------------------+----------------------------------+------------+\n| "s[i:j]" | slice of *s* from *i* to *j* | (3)(4) |\n+----------------------------+----------------------------------+------------+\n| "s[i:j:k]" | slice of *s* from *i* to *j* | (3)(5) |\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n| "s.index(x[, i[, j]])" | index of the first occurrence of | (8) |\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n\nSequences of the same type also support comparisons. In particular,\ntuples and lists are compared lexicographically by comparing\ncorresponding elements. This means that to compare equal, every\nelement must compare equal and the two sequences must be of the same\ntype and have the same length. (For full details see *Comparisons* in\nthe language reference.)\n\nNotes:\n\n1. While the "in" and "not in" operations are used only for simple\n containment testing in the general case, some specialised sequences\n (such as "str", "bytes" and "bytearray") also use them for\n subsequence testing:\n\n >>> "gg" in "eggs"\n True\n\n2. Values of *n* less than "0" are treated as "0" (which yields an\n empty sequence of the same type as *s*). Note also that the copies\n are shallow; nested structures are not copied. This often haunts\n new Python programmers; consider:\n\n >>> lists = [[]] * 3\n >>> lists\n [[], [], []]\n >>> lists[0].append(3)\n >>> lists\n [[3], [3], [3]]\n\n What has happened is that "[[]]" is a one-element list containing\n an empty list, so all three elements of "[[]] * 3" are (pointers\n to) this single empty list. Modifying any of the elements of\n "lists" modifies this single list. You can create a list of\n different lists this way:\n\n >>> lists = [[] for i in range(3)]\n >>> lists[0].append(3)\n >>> lists[1].append(5)\n >>> lists[2].append(7)\n >>> lists\n [[3], [5], [7]]\n\n3. If *i* or *j* is negative, the index is relative to the end of the\n string: "len(s) + i" or "len(s) + j" is substituted. But note that\n "-0" is still "0".\n\n4. The slice of *s* from *i* to *j* is defined as the sequence of\n items with index *k* such that "i <= k < j". If *i* or *j* is\n greater than "len(s)", use "len(s)". If *i* is omitted or "None",\n use "0". If *j* is omitted or "None", use "len(s)". If *i* is\n greater than or equal to *j*, the slice is empty.\n\n5. The slice of *s* from *i* to *j* with step *k* is defined as the\n sequence of items with index "x = i + n*k" such that "0 <= n <\n (j-i)/k". In other words, the indices are "i", "i+k", "i+2*k",\n "i+3*k" and so on, stopping when *j* is reached (but never\n including *j*). If *i* or *j* is greater than "len(s)", use\n "len(s)". If *i* or *j* are omitted or "None", they become "end"\n values (which end depends on the sign of *k*). Note, *k* cannot be\n zero. If *k* is "None", it is treated like "1".\n\n6. Concatenating immutable sequences always results in a new object.\n This means that building up a sequence by repeated concatenation\n will have a quadratic runtime cost in the total sequence length.\n To get a linear runtime cost, you must switch to one of the\n alternatives below:\n\n * if concatenating "str" objects, you can build a list and use\n "str.join()" at the end or else write to a "io.StringIO" instance\n and retrieve its value when complete\n\n * if concatenating "bytes" objects, you can similarly use\n "bytes.join()" or "io.BytesIO", or you can do in-place\n concatenation with a "bytearray" object. "bytearray" objects are\n mutable and have an efficient overallocation mechanism\n\n * if concatenating "tuple" objects, extend a "list" instead\n\n * for other types, investigate the relevant class documentation\n\n7. Some sequence types (such as "range") only support item sequences\n that follow specific patterns, and hence don\'t support sequence\n concatenation or repetition.\n\n8. "index" raises "ValueError" when *x* is not found in *s*. When\n supported, the additional arguments to the index method allow\n efficient searching of subsections of the sequence. Passing the\n extra arguments is roughly equivalent to using "s[i:j].index(x)",\n only without copying any data and with the returned index being\n relative to the start of the sequence rather than the start of the\n slice.\n\n\nImmutable Sequence Types\n========================\n\nThe only operation that immutable sequence types generally implement\nthat is not also implemented by mutable sequence types is support for\nthe "hash()" built-in.\n\nThis support allows immutable sequences, such as "tuple" instances, to\nbe used as "dict" keys and stored in "set" and "frozenset" instances.\n\nAttempting to hash an immutable sequence that contains unhashable\nvalues will result in "TypeError".\n\n\nMutable Sequence Types\n======================\n\nThe operations in the following table are defined on mutable sequence\ntypes. The "collections.abc.MutableSequence" ABC is provided to make\nit easier to correctly implement these operations on custom sequence\ntypes.\n\nIn the table *s* is an instance of a mutable sequence type, *t* is any\niterable object and *x* is an arbitrary object that meets any type and\nvalue restrictions imposed by *s* (for example, "bytearray" only\naccepts integers that meet the value restriction "0 <= x <= 255").\n\n+--------------------------------+----------------------------------+-----------------------+\n| Operation | Result | Notes |\n+================================+==================================+=======================+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s[i:j:k] = t" | the elements of "s[i:j:k]" are | (1) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.clear()" | removes all items from "s" (same | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.copy()" | creates a shallow copy of "s" | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.pop([i])" | retrieves the item at *i* and | (2) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.remove(x)" | remove the first item from *s* | (3) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.reverse()" | reverses the items of *s* in | (4) |\n+--------------------------------+----------------------------------+-----------------------+\n\nNotes:\n\n1. *t* must have the same length as the slice it is replacing.\n\n2. The optional argument *i* defaults to "-1", so that by default the\n last item is removed and returned.\n\n3. "remove" raises "ValueError" when *x* is not found in *s*.\n\n4. The "reverse()" method modifies the sequence in place for economy\n of space when reversing a large sequence. To remind users that it\n operates by side effect, it does not return the reversed sequence.\n\n5. "clear()" and "copy()" are included for consistency with the\n interfaces of mutable containers that don\'t support slicing\n operations (such as "dict" and "set")\n\n New in version 3.3: "clear()" and "copy()" methods.\n\n\nLists\n=====\n\nLists are mutable sequences, typically used to store collections of\nhomogeneous items (where the precise degree of similarity will vary by\napplication).\n\nclass class list([iterable])\n\n Lists may be constructed in several ways:\n\n * Using a pair of square brackets to denote the empty list: "[]"\n\n * Using square brackets, separating items with commas: "[a]", "[a,\n b, c]"\n\n * Using a list comprehension: "[x for x in iterable]"\n\n * Using the type constructor: "list()" or "list(iterable)"\n\n The constructor builds a list whose items are the same and in the\n same order as *iterable*\'s items. *iterable* may be either a\n sequence, a container that supports iteration, or an iterator\n object. If *iterable* is already a list, a copy is made and\n returned, similar to "iterable[:]". For example, "list(\'abc\')"\n returns "[\'a\', \'b\', \'c\']" and "list( (1, 2, 3) )" returns "[1, 2,\n 3]". If no argument is given, the constructor creates a new empty\n list, "[]".\n\n Many other operations also produce lists, including the "sorted()"\n built-in.\n\n Lists implement all of the *common* and *mutable* sequence\n operations. Lists also provide the following additional method:\n\n sort(*, key=None, reverse=None)\n\n This method sorts the list in place, using only "<" comparisons\n between items. Exceptions are not suppressed - if any comparison\n operations fail, the entire sort operation will fail (and the\n list will likely be left in a partially modified state).\n\n "sort()" accepts two arguments that can only be passed by\n keyword (*keyword-only arguments*):\n\n *key* specifies a function of one argument that is used to\n extract a comparison key from each list element (for example,\n "key=str.lower"). The key corresponding to each item in the list\n is calculated once and then used for the entire sorting process.\n The default value of "None" means that list items are sorted\n directly without calculating a separate key value.\n\n The "functools.cmp_to_key()" utility is available to convert a\n 2.x style *cmp* function to a *key* function.\n\n *reverse* is a boolean value. If set to "True", then the list\n elements are sorted as if each comparison were reversed.\n\n This method modifies the sequence in place for economy of space\n when sorting a large sequence. To remind users that it operates\n by side effect, it does not return the sorted sequence (use\n "sorted()" to explicitly request a new sorted list instance).\n\n The "sort()" method is guaranteed to be stable. A sort is\n stable if it guarantees not to change the relative order of\n elements that compare equal --- this is helpful for sorting in\n multiple passes (for example, sort by department, then by salary\n grade).\n\n **CPython implementation detail:** While a list is being sorted,\n the effect of attempting to mutate, or even inspect, the list is\n undefined. The C implementation of Python makes the list appear\n empty for the duration, and raises "ValueError" if it can detect\n that the list has been mutated during a sort.\n\n\nTuples\n======\n\nTuples are immutable sequences, typically used to store collections of\nheterogeneous data (such as the 2-tuples produced by the "enumerate()"\nbuilt-in). Tuples are also used for cases where an immutable sequence\nof homogeneous data is needed (such as allowing storage in a "set" or\n"dict" instance).\n\nclass class tuple([iterable])\n\n Tuples may be constructed in a number of ways:\n\n * Using a pair of parentheses to denote the empty tuple: "()"\n\n * Using a trailing comma for a singleton tuple: "a," or "(a,)"\n\n * Separating items with commas: "a, b, c" or "(a, b, c)"\n\n * Using the "tuple()" built-in: "tuple()" or "tuple(iterable)"\n\n The constructor builds a tuple whose items are the same and in the\n same order as *iterable*\'s items. *iterable* may be either a\n sequence, a container that supports iteration, or an iterator\n object. If *iterable* is already a tuple, it is returned\n unchanged. For example, "tuple(\'abc\')" returns "(\'a\', \'b\', \'c\')"\n and "tuple( [1, 2, 3] )" returns "(1, 2, 3)". If no argument is\n given, the constructor creates a new empty tuple, "()".\n\n Note that it is actually the comma which makes a tuple, not the\n parentheses. The parentheses are optional, except in the empty\n tuple case, or when they are needed to avoid syntactic ambiguity.\n For example, "f(a, b, c)" is a function call with three arguments,\n while "f((a, b, c))" is a function call with a 3-tuple as the sole\n argument.\n\n Tuples implement all of the *common* sequence operations.\n\nFor heterogeneous collections of data where access by name is clearer\nthan access by index, "collections.namedtuple()" may be a more\nappropriate choice than a simple tuple object.\n\n\nRanges\n======\n\nThe "range" type represents an immutable sequence of numbers and is\ncommonly used for looping a specific number of times in "for" loops.\n\nclass class range(stop)\nclass class range(start, stop[, step])\n\n The arguments to the range constructor must be integers (either\n built-in "int" or any object that implements the "__index__"\n special method). If the *step* argument is omitted, it defaults to\n "1". If the *start* argument is omitted, it defaults to "0". If\n *step* is zero, "ValueError" is raised.\n\n For a positive *step*, the contents of a range "r" are determined\n by the formula "r[i] = start + step*i" where "i >= 0" and "r[i] <\n stop".\n\n For a negative *step*, the contents of the range are still\n determined by the formula "r[i] = start + step*i", but the\n constraints are "i >= 0" and "r[i] > stop".\n\n A range object will be empty if "r[0]" does not meet the value\n constraint. Ranges do support negative indices, but these are\n interpreted as indexing from the end of the sequence determined by\n the positive indices.\n\n Ranges containing absolute values larger than "sys.maxsize" are\n permitted but some features (such as "len()") may raise\n "OverflowError".\n\n Range examples:\n\n >>> list(range(10))\n [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]\n >>> list(range(1, 11))\n [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]\n >>> list(range(0, 30, 5))\n [0, 5, 10, 15, 20, 25]\n >>> list(range(0, 10, 3))\n [0, 3, 6, 9]\n >>> list(range(0, -10, -1))\n [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]\n >>> list(range(0))\n []\n >>> list(range(1, 0))\n []\n\n Ranges implement all of the *common* sequence operations except\n concatenation and repetition (due to the fact that range objects\n can only represent sequences that follow a strict pattern and\n repetition and concatenation will usually violate that pattern).\n\nThe advantage of the "range" type over a regular "list" or "tuple" is\nthat a "range" object will always take the same (small) amount of\nmemory, no matter the size of the range it represents (as it only\nstores the "start", "stop" and "step" values, calculating individual\nitems and subranges as needed).\n\nRange objects implement the "collections.abc.Sequence" ABC, and\nprovide features such as containment tests, element index lookup,\nslicing and support for negative indices (see *Sequence Types ---\nlist, tuple, range*):\n\n>>> r = range(0, 20, 2)\n>>> r\nrange(0, 20, 2)\n>>> 11 in r\nFalse\n>>> 10 in r\nTrue\n>>> r.index(10)\n5\n>>> r[5]\n10\n>>> r[:5]\nrange(0, 10, 2)\n>>> r[-1]\n18\n\nTesting range objects for equality with "==" and "!=" compares them as\nsequences. That is, two range objects are considered equal if they\nrepresent the same sequence of values. (Note that two range objects\nthat compare equal might have different "start", "stop" and "step"\nattributes, for example "range(0) == range(2, 1, 3)" or "range(0, 3,\n2) == range(0, 4, 2)".)\n\nChanged in version 3.2: Implement the Sequence ABC. Support slicing\nand negative indices. Test "int" objects for membership in constant\ntime instead of iterating through all items.\n\nChanged in version 3.3: Define \'==\' and \'!=\' to compare range objects\nbased on the sequence of values they define (instead of comparing\nbased on object identity).\n\nNew in version 3.3: The "start", "stop" and "step" attributes.\n', - 'typesseq-mutable': '\nMutable Sequence Types\n**********************\n\nThe operations in the following table are defined on mutable sequence\ntypes. The "collections.abc.MutableSequence" ABC is provided to make\nit easier to correctly implement these operations on custom sequence\ntypes.\n\nIn the table *s* is an instance of a mutable sequence type, *t* is any\niterable object and *x* is an arbitrary object that meets any type and\nvalue restrictions imposed by *s* (for example, "bytearray" only\naccepts integers that meet the value restriction "0 <= x <= 255").\n\n+--------------------------------+----------------------------------+-----------------------+\n| Operation | Result | Notes |\n+================================+==================================+=======================+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s[i:j:k] = t" | the elements of "s[i:j:k]" are | (1) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.clear()" | removes all items from "s" (same | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.copy()" | creates a shallow copy of "s" | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.pop([i])" | retrieves the item at *i* and | (2) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.remove(x)" | remove the first item from *s* | (3) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.reverse()" | reverses the items of *s* in | (4) |\n+--------------------------------+----------------------------------+-----------------------+\n\nNotes:\n\n1. *t* must have the same length as the slice it is replacing.\n\n2. The optional argument *i* defaults to "-1", so that by default the\n last item is removed and returned.\n\n3. "remove" raises "ValueError" when *x* is not found in *s*.\n\n4. The "reverse()" method modifies the sequence in place for economy\n of space when reversing a large sequence. To remind users that it\n operates by side effect, it does not return the reversed sequence.\n\n5. "clear()" and "copy()" are included for consistency with the\n interfaces of mutable containers that don\'t support slicing\n operations (such as "dict" and "set")\n\n New in version 3.3: "clear()" and "copy()" methods.\n', + 'typesseq': '\nSequence Types --- "list", "tuple", "range"\n*******************************************\n\nThere are three basic sequence types: lists, tuples, and range\nobjects. Additional sequence types tailored for processing of *binary\ndata* and *text strings* are described in dedicated sections.\n\n\nCommon Sequence Operations\n==========================\n\nThe operations in the following table are supported by most sequence\ntypes, both mutable and immutable. The "collections.abc.Sequence" ABC\nis provided to make it easier to correctly implement these operations\non custom sequence types.\n\nThis table lists the sequence operations sorted in ascending priority\n(operations in the same box have the same priority). In the table,\n*s* and *t* are sequences of the same type, *n*, *i*, *j* and *k* are\nintegers and *x* is an arbitrary object that meets any type and value\nrestrictions imposed by *s*.\n\nThe "in" and "not in" operations have the same priorities as the\ncomparison operations. The "+" (concatenation) and "*" (repetition)\noperations have the same priority as the corresponding numeric\noperations.\n\n+----------------------------+----------------------------------+------------+\n| Operation | Result | Notes |\n+============================+==================================+============+\n| "x in s" | "True" if an item of *s* is | (1) |\n+----------------------------+----------------------------------+------------+\n| "x not in s" | "False" if an item of *s* is | (1) |\n+----------------------------+----------------------------------+------------+\n| "s + t" | the concatenation of *s* and *t* | (6)(7) |\n+----------------------------+----------------------------------+------------+\n| "s * n" or "n * s" | *n* shallow copies of *s* | (2)(7) |\n+----------------------------+----------------------------------+------------+\n| "s[i]" | *i*th item of *s*, origin 0 | (3) |\n+----------------------------+----------------------------------+------------+\n| "s[i:j]" | slice of *s* from *i* to *j* | (3)(4) |\n+----------------------------+----------------------------------+------------+\n| "s[i:j:k]" | slice of *s* from *i* to *j* | (3)(5) |\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n| "s.index(x[, i[, j]])" | index of the first occurrence of | (8) |\n+----------------------------+----------------------------------+------------+\n+----------------------------+----------------------------------+------------+\n\nSequences of the same type also support comparisons. In particular,\ntuples and lists are compared lexicographically by comparing\ncorresponding elements. This means that to compare equal, every\nelement must compare equal and the two sequences must be of the same\ntype and have the same length. (For full details see *Comparisons* in\nthe language reference.)\n\nNotes:\n\n1. While the "in" and "not in" operations are used only for simple\n containment testing in the general case, some specialised sequences\n (such as "str", "bytes" and "bytearray") also use them for\n subsequence testing:\n\n >>> "gg" in "eggs"\n True\n\n2. Values of *n* less than "0" are treated as "0" (which yields an\n empty sequence of the same type as *s*). Note also that the copies\n are shallow; nested structures are not copied. This often haunts\n new Python programmers; consider:\n\n >>> lists = [[]] * 3\n >>> lists\n [[], [], []]\n >>> lists[0].append(3)\n >>> lists\n [[3], [3], [3]]\n\n What has happened is that "[[]]" is a one-element list containing\n an empty list, so all three elements of "[[]] * 3" are (pointers\n to) this single empty list. Modifying any of the elements of\n "lists" modifies this single list. You can create a list of\n different lists this way:\n\n >>> lists = [[] for i in range(3)]\n >>> lists[0].append(3)\n >>> lists[1].append(5)\n >>> lists[2].append(7)\n >>> lists\n [[3], [5], [7]]\n\n3. If *i* or *j* is negative, the index is relative to the end of\n the string: "len(s) + i" or "len(s) + j" is substituted. But note\n that "-0" is still "0".\n\n4. The slice of *s* from *i* to *j* is defined as the sequence of\n items with index *k* such that "i <= k < j". If *i* or *j* is\n greater than "len(s)", use "len(s)". If *i* is omitted or "None",\n use "0". If *j* is omitted or "None", use "len(s)". If *i* is\n greater than or equal to *j*, the slice is empty.\n\n5. The slice of *s* from *i* to *j* with step *k* is defined as the\n sequence of items with index "x = i + n*k" such that "0 <= n <\n (j-i)/k". In other words, the indices are "i", "i+k", "i+2*k",\n "i+3*k" and so on, stopping when *j* is reached (but never\n including *j*). If *i* or *j* is greater than "len(s)", use\n "len(s)". If *i* or *j* are omitted or "None", they become "end"\n values (which end depends on the sign of *k*). Note, *k* cannot be\n zero. If *k* is "None", it is treated like "1".\n\n6. Concatenating immutable sequences always results in a new\n object. This means that building up a sequence by repeated\n concatenation will have a quadratic runtime cost in the total\n sequence length. To get a linear runtime cost, you must switch to\n one of the alternatives below:\n\n * if concatenating "str" objects, you can build a list and use\n "str.join()" at the end or else write to a "io.StringIO" instance\n and retrieve its value when complete\n\n * if concatenating "bytes" objects, you can similarly use\n "bytes.join()" or "io.BytesIO", or you can do in-place\n concatenation with a "bytearray" object. "bytearray" objects are\n mutable and have an efficient overallocation mechanism\n\n * if concatenating "tuple" objects, extend a "list" instead\n\n * for other types, investigate the relevant class documentation\n\n7. Some sequence types (such as "range") only support item\n sequences that follow specific patterns, and hence don\'t support\n sequence concatenation or repetition.\n\n8. "index" raises "ValueError" when *x* is not found in *s*. When\n supported, the additional arguments to the index method allow\n efficient searching of subsections of the sequence. Passing the\n extra arguments is roughly equivalent to using "s[i:j].index(x)",\n only without copying any data and with the returned index being\n relative to the start of the sequence rather than the start of the\n slice.\n\n\nImmutable Sequence Types\n========================\n\nThe only operation that immutable sequence types generally implement\nthat is not also implemented by mutable sequence types is support for\nthe "hash()" built-in.\n\nThis support allows immutable sequences, such as "tuple" instances, to\nbe used as "dict" keys and stored in "set" and "frozenset" instances.\n\nAttempting to hash an immutable sequence that contains unhashable\nvalues will result in "TypeError".\n\n\nMutable Sequence Types\n======================\n\nThe operations in the following table are defined on mutable sequence\ntypes. The "collections.abc.MutableSequence" ABC is provided to make\nit easier to correctly implement these operations on custom sequence\ntypes.\n\nIn the table *s* is an instance of a mutable sequence type, *t* is any\niterable object and *x* is an arbitrary object that meets any type and\nvalue restrictions imposed by *s* (for example, "bytearray" only\naccepts integers that meet the value restriction "0 <= x <= 255").\n\n+--------------------------------+----------------------------------+-----------------------+\n| Operation | Result | Notes |\n+================================+==================================+=======================+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s[i:j:k] = t" | the elements of "s[i:j:k]" are | (1) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.clear()" | removes all items from "s" (same | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.copy()" | creates a shallow copy of "s" | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.pop([i])" | retrieves the item at *i* and | (2) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.remove(x)" | remove the first item from *s* | (3) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.reverse()" | reverses the items of *s* in | (4) |\n+--------------------------------+----------------------------------+-----------------------+\n\nNotes:\n\n1. *t* must have the same length as the slice it is replacing.\n\n2. The optional argument *i* defaults to "-1", so that by default\n the last item is removed and returned.\n\n3. "remove" raises "ValueError" when *x* is not found in *s*.\n\n4. The "reverse()" method modifies the sequence in place for\n economy of space when reversing a large sequence. To remind users\n that it operates by side effect, it does not return the reversed\n sequence.\n\n5. "clear()" and "copy()" are included for consistency with the\n interfaces of mutable containers that don\'t support slicing\n operations (such as "dict" and "set")\n\n New in version 3.3: "clear()" and "copy()" methods.\n\n\nLists\n=====\n\nLists are mutable sequences, typically used to store collections of\nhomogeneous items (where the precise degree of similarity will vary by\napplication).\n\nclass class list([iterable])\n\n Lists may be constructed in several ways:\n\n * Using a pair of square brackets to denote the empty list: "[]"\n\n * Using square brackets, separating items with commas: "[a]",\n "[a, b, c]"\n\n * Using a list comprehension: "[x for x in iterable]"\n\n * Using the type constructor: "list()" or "list(iterable)"\n\n The constructor builds a list whose items are the same and in the\n same order as *iterable*\'s items. *iterable* may be either a\n sequence, a container that supports iteration, or an iterator\n object. If *iterable* is already a list, a copy is made and\n returned, similar to "iterable[:]". For example, "list(\'abc\')"\n returns "[\'a\', \'b\', \'c\']" and "list( (1, 2, 3) )" returns "[1, 2,\n 3]". If no argument is given, the constructor creates a new empty\n list, "[]".\n\n Many other operations also produce lists, including the "sorted()"\n built-in.\n\n Lists implement all of the *common* and *mutable* sequence\n operations. Lists also provide the following additional method:\n\n sort(*, key=None, reverse=None)\n\n This method sorts the list in place, using only "<" comparisons\n between items. Exceptions are not suppressed - if any comparison\n operations fail, the entire sort operation will fail (and the\n list will likely be left in a partially modified state).\n\n "sort()" accepts two arguments that can only be passed by\n keyword (*keyword-only arguments*):\n\n *key* specifies a function of one argument that is used to\n extract a comparison key from each list element (for example,\n "key=str.lower"). The key corresponding to each item in the list\n is calculated once and then used for the entire sorting process.\n The default value of "None" means that list items are sorted\n directly without calculating a separate key value.\n\n The "functools.cmp_to_key()" utility is available to convert a\n 2.x style *cmp* function to a *key* function.\n\n *reverse* is a boolean value. If set to "True", then the list\n elements are sorted as if each comparison were reversed.\n\n This method modifies the sequence in place for economy of space\n when sorting a large sequence. To remind users that it operates\n by side effect, it does not return the sorted sequence (use\n "sorted()" to explicitly request a new sorted list instance).\n\n The "sort()" method is guaranteed to be stable. A sort is\n stable if it guarantees not to change the relative order of\n elements that compare equal --- this is helpful for sorting in\n multiple passes (for example, sort by department, then by salary\n grade).\n\n **CPython implementation detail:** While a list is being sorted,\n the effect of attempting to mutate, or even inspect, the list is\n undefined. The C implementation of Python makes the list appear\n empty for the duration, and raises "ValueError" if it can detect\n that the list has been mutated during a sort.\n\n\nTuples\n======\n\nTuples are immutable sequences, typically used to store collections of\nheterogeneous data (such as the 2-tuples produced by the "enumerate()"\nbuilt-in). Tuples are also used for cases where an immutable sequence\nof homogeneous data is needed (such as allowing storage in a "set" or\n"dict" instance).\n\nclass class tuple([iterable])\n\n Tuples may be constructed in a number of ways:\n\n * Using a pair of parentheses to denote the empty tuple: "()"\n\n * Using a trailing comma for a singleton tuple: "a," or "(a,)"\n\n * Separating items with commas: "a, b, c" or "(a, b, c)"\n\n * Using the "tuple()" built-in: "tuple()" or "tuple(iterable)"\n\n The constructor builds a tuple whose items are the same and in the\n same order as *iterable*\'s items. *iterable* may be either a\n sequence, a container that supports iteration, or an iterator\n object. If *iterable* is already a tuple, it is returned\n unchanged. For example, "tuple(\'abc\')" returns "(\'a\', \'b\', \'c\')"\n and "tuple( [1, 2, 3] )" returns "(1, 2, 3)". If no argument is\n given, the constructor creates a new empty tuple, "()".\n\n Note that it is actually the comma which makes a tuple, not the\n parentheses. The parentheses are optional, except in the empty\n tuple case, or when they are needed to avoid syntactic ambiguity.\n For example, "f(a, b, c)" is a function call with three arguments,\n while "f((a, b, c))" is a function call with a 3-tuple as the sole\n argument.\n\n Tuples implement all of the *common* sequence operations.\n\nFor heterogeneous collections of data where access by name is clearer\nthan access by index, "collections.namedtuple()" may be a more\nappropriate choice than a simple tuple object.\n\n\nRanges\n======\n\nThe "range" type represents an immutable sequence of numbers and is\ncommonly used for looping a specific number of times in "for" loops.\n\nclass class range(stop)\nclass class range(start, stop[, step])\n\n The arguments to the range constructor must be integers (either\n built-in "int" or any object that implements the "__index__"\n special method). If the *step* argument is omitted, it defaults to\n "1". If the *start* argument is omitted, it defaults to "0". If\n *step* is zero, "ValueError" is raised.\n\n For a positive *step*, the contents of a range "r" are determined\n by the formula "r[i] = start + step*i" where "i >= 0" and "r[i] <\n stop".\n\n For a negative *step*, the contents of the range are still\n determined by the formula "r[i] = start + step*i", but the\n constraints are "i >= 0" and "r[i] > stop".\n\n A range object will be empty if "r[0]" does not meet the value\n constraint. Ranges do support negative indices, but these are\n interpreted as indexing from the end of the sequence determined by\n the positive indices.\n\n Ranges containing absolute values larger than "sys.maxsize" are\n permitted but some features (such as "len()") may raise\n "OverflowError".\n\n Range examples:\n\n >>> list(range(10))\n [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]\n >>> list(range(1, 11))\n [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]\n >>> list(range(0, 30, 5))\n [0, 5, 10, 15, 20, 25]\n >>> list(range(0, 10, 3))\n [0, 3, 6, 9]\n >>> list(range(0, -10, -1))\n [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]\n >>> list(range(0))\n []\n >>> list(range(1, 0))\n []\n\n Ranges implement all of the *common* sequence operations except\n concatenation and repetition (due to the fact that range objects\n can only represent sequences that follow a strict pattern and\n repetition and concatenation will usually violate that pattern).\n\nThe advantage of the "range" type over a regular "list" or "tuple" is\nthat a "range" object will always take the same (small) amount of\nmemory, no matter the size of the range it represents (as it only\nstores the "start", "stop" and "step" values, calculating individual\nitems and subranges as needed).\n\nRange objects implement the "collections.abc.Sequence" ABC, and\nprovide features such as containment tests, element index lookup,\nslicing and support for negative indices (see *Sequence Types ---\nlist, tuple, range*):\n\n>>> r = range(0, 20, 2)\n>>> r\nrange(0, 20, 2)\n>>> 11 in r\nFalse\n>>> 10 in r\nTrue\n>>> r.index(10)\n5\n>>> r[5]\n10\n>>> r[:5]\nrange(0, 10, 2)\n>>> r[-1]\n18\n\nTesting range objects for equality with "==" and "!=" compares them as\nsequences. That is, two range objects are considered equal if they\nrepresent the same sequence of values. (Note that two range objects\nthat compare equal might have different "start", "stop" and "step"\nattributes, for example "range(0) == range(2, 1, 3)" or "range(0, 3,\n2) == range(0, 4, 2)".)\n\nChanged in version 3.2: Implement the Sequence ABC. Support slicing\nand negative indices. Test "int" objects for membership in constant\ntime instead of iterating through all items.\n\nChanged in version 3.3: Define \'==\' and \'!=\' to compare range objects\nbased on the sequence of values they define (instead of comparing\nbased on object identity).\n\nNew in version 3.3: The "start", "stop" and "step" attributes.\n', + 'typesseq-mutable': '\nMutable Sequence Types\n**********************\n\nThe operations in the following table are defined on mutable sequence\ntypes. The "collections.abc.MutableSequence" ABC is provided to make\nit easier to correctly implement these operations on custom sequence\ntypes.\n\nIn the table *s* is an instance of a mutable sequence type, *t* is any\niterable object and *x* is an arbitrary object that meets any type and\nvalue restrictions imposed by *s* (for example, "bytearray" only\naccepts integers that meet the value restriction "0 <= x <= 255").\n\n+--------------------------------+----------------------------------+-----------------------+\n| Operation | Result | Notes |\n+================================+==================================+=======================+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s[i:j:k] = t" | the elements of "s[i:j:k]" are | (1) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.clear()" | removes all items from "s" (same | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.copy()" | creates a shallow copy of "s" | (5) |\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n+--------------------------------+----------------------------------+-----------------------+\n| "s.pop([i])" | retrieves the item at *i* and | (2) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.remove(x)" | remove the first item from *s* | (3) |\n+--------------------------------+----------------------------------+-----------------------+\n| "s.reverse()" | reverses the items of *s* in | (4) |\n+--------------------------------+----------------------------------+-----------------------+\n\nNotes:\n\n1. *t* must have the same length as the slice it is replacing.\n\n2. The optional argument *i* defaults to "-1", so that by default\n the last item is removed and returned.\n\n3. "remove" raises "ValueError" when *x* is not found in *s*.\n\n4. The "reverse()" method modifies the sequence in place for\n economy of space when reversing a large sequence. To remind users\n that it operates by side effect, it does not return the reversed\n sequence.\n\n5. "clear()" and "copy()" are included for consistency with the\n interfaces of mutable containers that don\'t support slicing\n operations (such as "dict" and "set")\n\n New in version 3.3: "clear()" and "copy()" methods.\n', 'unary': '\nUnary arithmetic and bitwise operations\n***************************************\n\nAll unary arithmetic and bitwise operations have the same priority:\n\n u_expr ::= power | "-" u_expr | "+" u_expr | "~" u_expr\n\nThe unary "-" (minus) operator yields the negation of its numeric\nargument.\n\nThe unary "+" (plus) operator yields its numeric argument unchanged.\n\nThe unary "~" (invert) operator yields the bitwise inversion of its\ninteger argument. The bitwise inversion of "x" is defined as\n"-(x+1)". It only applies to integral numbers.\n\nIn all three cases, if the argument does not have the proper type, a\n"TypeError" exception is raised.\n', 'while': '\nThe "while" statement\n*********************\n\nThe "while" statement is used for repeated execution as long as an\nexpression is true:\n\n while_stmt ::= "while" expression ":" suite\n ["else" ":" suite]\n\nThis repeatedly tests the expression and, if it is true, executes the\nfirst suite; if the expression is false (which may be the first time\nit is tested) the suite of the "else" clause, if present, is executed\nand the loop terminates.\n\nA "break" statement executed in the first suite terminates the loop\nwithout executing the "else" clause\'s suite. A "continue" statement\nexecuted in the first suite skips the rest of the suite and goes back\nto testing the expression.\n', - 'with': '\nThe "with" statement\n********************\n\nThe "with" statement is used to wrap the execution of a block with\nmethods defined by a context manager (see section *With Statement\nContext Managers*). This allows common "try"..."except"..."finally"\nusage patterns to be encapsulated for convenient reuse.\n\n with_stmt ::= "with" with_item ("," with_item)* ":" suite\n with_item ::= expression ["as" target]\n\nThe execution of the "with" statement with one "item" proceeds as\nfollows:\n\n1. The context expression (the expression given in the "with_item") is\n evaluated to obtain a context manager.\n\n2. The context manager\'s "__exit__()" is loaded for later use.\n\n3. The context manager\'s "__enter__()" method is invoked.\n\n4. If a target was included in the "with" statement, the return value\n from "__enter__()" is assigned to it.\n\n Note: The "with" statement guarantees that if the "__enter__()" method\n returns without an error, then "__exit__()" will always be\n called. Thus, if an error occurs during the assignment to the\n target list, it will be treated the same as an error occurring\n within the suite would be. See step 6 below.\n\n5. The suite is executed.\n\n6. The context manager\'s "__exit__()" method is invoked. If an\n exception caused the suite to be exited, its type, value, and\n traceback are passed as arguments to "__exit__()". Otherwise, three\n "None" arguments are supplied.\n\n If the suite was exited due to an exception, and the return value\n from the "__exit__()" method was false, the exception is reraised.\n If the return value was true, the exception is suppressed, and\n execution continues with the statement following the "with"\n statement.\n\n If the suite was exited for any reason other than an exception, the\n return value from "__exit__()" is ignored, and execution proceeds\n at the normal location for the kind of exit that was taken.\n\nWith more than one item, the context managers are processed as if\nmultiple "with" statements were nested:\n\n with A() as a, B() as b:\n suite\n\nis equivalent to\n\n with A() as a:\n with B() as b:\n suite\n\nChanged in version 3.1: Support for multiple context expressions.\n\nSee also:\n\n **PEP 0343** - The "with" statement\n The specification, background, and examples for the Python\n "with" statement.\n', + 'with': '\nThe "with" statement\n********************\n\nThe "with" statement is used to wrap the execution of a block with\nmethods defined by a context manager (see section *With Statement\nContext Managers*). This allows common "try"..."except"..."finally"\nusage patterns to be encapsulated for convenient reuse.\n\n with_stmt ::= "with" with_item ("," with_item)* ":" suite\n with_item ::= expression ["as" target]\n\nThe execution of the "with" statement with one "item" proceeds as\nfollows:\n\n1. The context expression (the expression given in the "with_item")\n is evaluated to obtain a context manager.\n\n2. The context manager\'s "__exit__()" is loaded for later use.\n\n3. The context manager\'s "__enter__()" method is invoked.\n\n4. If a target was included in the "with" statement, the return\n value from "__enter__()" is assigned to it.\n\n Note: The "with" statement guarantees that if the "__enter__()"\n method returns without an error, then "__exit__()" will always be\n called. Thus, if an error occurs during the assignment to the\n target list, it will be treated the same as an error occurring\n within the suite would be. See step 6 below.\n\n5. The suite is executed.\n\n6. The context manager\'s "__exit__()" method is invoked. If an\n exception caused the suite to be exited, its type, value, and\n traceback are passed as arguments to "__exit__()". Otherwise, three\n "None" arguments are supplied.\n\n If the suite was exited due to an exception, and the return value\n from the "__exit__()" method was false, the exception is reraised.\n If the return value was true, the exception is suppressed, and\n execution continues with the statement following the "with"\n statement.\n\n If the suite was exited for any reason other than an exception, the\n return value from "__exit__()" is ignored, and execution proceeds\n at the normal location for the kind of exit that was taken.\n\nWith more than one item, the context managers are processed as if\nmultiple "with" statements were nested:\n\n with A() as a, B() as b:\n suite\n\nis equivalent to\n\n with A() as a:\n with B() as b:\n suite\n\nChanged in version 3.1: Support for multiple context expressions.\n\nSee also: **PEP 0343** - The "with" statement\n\n The specification, background, and examples for the Python "with"\n statement.\n', 'yield': '\nThe "yield" statement\n*********************\n\n yield_stmt ::= yield_expression\n\nA "yield" statement is semantically equivalent to a *yield\nexpression*. The yield statement can be used to omit the parentheses\nthat would otherwise be required in the equivalent yield expression\nstatement. For example, the yield statements\n\n yield <expr>\n yield from <expr>\n\nare equivalent to the yield expression statements\n\n (yield <expr>)\n (yield from <expr>)\n\nYield expressions and statements are only used when defining a\n*generator* function, and are only used in the body of the generator\nfunction. Using yield in a function definition is sufficient to cause\nthat definition to create a generator function instead of a normal\nfunction.\n\nFor full details of "yield" semantics, refer to the *Yield\nexpressions* section.\n'} diff --git a/Lib/random.py b/Lib/random.py index 4642928..1f5be45 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -687,7 +687,7 @@ def _test_generator(n, func, args): print(round(t1-t0, 3), 'sec,', end=' ') avg = total/n stddev = _sqrt(sqsum/n - avg*avg) - print('avg %g, stddev %g, min %g, max %g' % \ + print('avg %g, stddev %g, min %g, max %g\n' % \ (avg, stddev, smallest, largest)) diff --git a/Lib/runpy.py b/Lib/runpy.py index 0bb57d7..d9c643d 100644 --- a/Lib/runpy.py +++ b/Lib/runpy.py @@ -58,7 +58,7 @@ class _ModifiedArgv0(object): self.value = self._sentinel sys.argv[0] = self._saved_value -# TODO: Replace these helpers with importlib._bootstrap._SpecMethods +# TODO: Replace these helpers with importlib._bootstrap functions def _run_code(code, run_globals, init_globals=None, mod_name=None, mod_spec=None, pkg_name=None, script_name=None): diff --git a/Lib/selectors.py b/Lib/selectors.py index 9be9225..4e9ae6e 100644 --- a/Lib/selectors.py +++ b/Lib/selectors.py @@ -441,6 +441,64 @@ if hasattr(select, 'epoll'): super().close() +if hasattr(select, 'devpoll'): + + class DevpollSelector(_BaseSelectorImpl): + """Solaris /dev/poll selector.""" + + def __init__(self): + super().__init__() + self._devpoll = select.devpoll() + + def fileno(self): + return self._devpoll.fileno() + + def register(self, fileobj, events, data=None): + key = super().register(fileobj, events, data) + poll_events = 0 + if events & EVENT_READ: + poll_events |= select.POLLIN + if events & EVENT_WRITE: + poll_events |= select.POLLOUT + self._devpoll.register(key.fd, poll_events) + return key + + def unregister(self, fileobj): + key = super().unregister(fileobj) + self._devpoll.unregister(key.fd) + return key + + def select(self, timeout=None): + if timeout is None: + timeout = None + elif timeout <= 0: + timeout = 0 + else: + # devpoll() has a resolution of 1 millisecond, round away from + # zero to wait *at least* timeout seconds. + timeout = math.ceil(timeout * 1e3) + ready = [] + try: + fd_event_list = self._devpoll.poll(timeout) + except InterruptedError: + return ready + for fd, event in fd_event_list: + events = 0 + if event & ~select.POLLIN: + events |= EVENT_WRITE + if event & ~select.POLLOUT: + events |= EVENT_READ + + key = self._key_from_fd(fd) + if key: + ready.append((key, events & key.events)) + return ready + + def close(self): + self._devpoll.close() + super().close() + + if hasattr(select, 'kqueue'): class KqueueSelector(_BaseSelectorImpl): @@ -513,12 +571,14 @@ if hasattr(select, 'kqueue'): super().close() -# Choose the best implementation: roughly, epoll|kqueue > poll > select. +# Choose the best implementation: roughly, epoll|kqueue|devpoll > poll > select. # select() also can't accept a FD > FD_SETSIZE (usually around 1024) if 'KqueueSelector' in globals(): DefaultSelector = KqueueSelector elif 'EpollSelector' in globals(): DefaultSelector = EpollSelector +elif 'DevpollSelector' in globals(): + DefaultSelector = DevpollSelector elif 'PollSelector' in globals(): DefaultSelector = PollSelector else: diff --git a/Lib/shutil.py b/Lib/shutil.py index 0cd6ec4..b59017b 100644 --- a/Lib/shutil.py +++ b/Lib/shutil.py @@ -486,7 +486,7 @@ def _basename(path): sep = os.path.sep + (os.path.altsep or '') return os.path.basename(path.rstrip(sep)) -def move(src, dst): +def move(src, dst, copy_function=copy2): """Recursively move a file or directory to another location. This is similar to the Unix "mv" command. Return the file or directory's destination. @@ -503,6 +503,11 @@ def move(src, dst): recreated under the new name if os.rename() fails because of cross filesystem renames. + The optional `copy_function` argument is a callable that will be used + to copy the source or it will be delegated to `copytree`. + By default, copy2() is used, but any function that supports the same + signature (like copy()) can be used. + A lot more could be done here... A look at a mv.c shows a lot of the issues this implementation glosses over. @@ -527,11 +532,13 @@ def move(src, dst): os.unlink(src) elif os.path.isdir(src): if _destinsrc(src, dst): - raise Error("Cannot move a directory '%s' into itself '%s'." % (src, dst)) - copytree(src, real_dst, symlinks=True) + raise Error("Cannot move a directory '%s' into itself" + " '%s'." % (src, dst)) + copytree(src, real_dst, copy_function=copy_function, + symlinks=True) rmtree(src) else: - copy2(src, real_dst) + copy_function(src, real_dst) os.unlink(src) return real_dst @@ -630,23 +637,6 @@ def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0, return archive_name -def _call_external_zip(base_dir, zip_filename, verbose=False, dry_run=False): - # XXX see if we want to keep an external call here - if verbose: - zipoptions = "-r" - else: - zipoptions = "-rq" - from distutils.errors import DistutilsExecError - from distutils.spawn import spawn - try: - spawn(["zip", zipoptions, zip_filename, base_dir], dry_run=dry_run) - except DistutilsExecError: - # XXX really should distinguish between "couldn't find - # external 'zip' command" and "zip failed". - raise ExecError("unable to create zip file '%s': " - "could neither import the 'zipfile' module nor " - "find a standalone zip utility") % zip_filename - def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None): """Create a zip file from all the files under 'base_dir'. @@ -656,6 +646,8 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None): available, raises ExecError. Returns the name of the output zip file. """ + import zipfile + zip_filename = base_name + ".zip" archive_dir = os.path.dirname(base_name) @@ -665,30 +657,20 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None): if not dry_run: os.makedirs(archive_dir) - # If zipfile module is not available, try spawning an external 'zip' - # command. - try: - import zipfile - except ImportError: - zipfile = None - - if zipfile is None: - _call_external_zip(base_dir, zip_filename, verbose, dry_run) - else: - if logger is not None: - logger.info("creating '%s' and adding '%s' to it", - zip_filename, base_dir) + if logger is not None: + logger.info("creating '%s' and adding '%s' to it", + zip_filename, base_dir) - if not dry_run: - with zipfile.ZipFile(zip_filename, "w", - compression=zipfile.ZIP_DEFLATED) as zf: - for dirpath, dirnames, filenames in os.walk(base_dir): - for name in filenames: - path = os.path.normpath(os.path.join(dirpath, name)) - if os.path.isfile(path): - zf.write(path, path) - if logger is not None: - logger.info("adding '%s'", path) + if not dry_run: + with zipfile.ZipFile(zip_filename, "w", + compression=zipfile.ZIP_DEFLATED) as zf: + for dirpath, dirnames, filenames in os.walk(base_dir): + for name in filenames: + path = os.path.normpath(os.path.join(dirpath, name)) + if os.path.isfile(path): + zf.write(path, path) + if logger is not None: + logger.info("adding '%s'", path) return zip_filename diff --git a/Lib/signal.py b/Lib/signal.py new file mode 100644 index 0000000..0db3df8 --- /dev/null +++ b/Lib/signal.py @@ -0,0 +1,85 @@ +import _signal +from _signal import * +from functools import wraps as _wraps +from enum import IntEnum as _IntEnum + +_globals = globals() + +Signals = _IntEnum( + 'Signals', + {name: value for name, value in _globals.items() + if name.isupper() + and (name.startswith('SIG') and not name.startswith('SIG_')) + or name.startswith('CTRL_')}) + +class Handlers(_IntEnum): + SIG_DFL = _signal.SIG_DFL + SIG_IGN = _signal.SIG_IGN + +_globals.update(Signals.__members__) +_globals.update(Handlers.__members__) + +if 'pthread_sigmask' in _globals: + class Sigmasks(_IntEnum): + SIG_BLOCK = _signal.SIG_BLOCK + SIG_UNBLOCK = _signal.SIG_UNBLOCK + SIG_SETMASK = _signal.SIG_SETMASK + + _globals.update(Sigmasks.__members__) + + +def _int_to_enum(value, enum_klass): + """Convert a numeric value to an IntEnum member. + If it's not a known member, return the numeric value itself. + """ + try: + return enum_klass(value) + except ValueError: + return value + + +def _enum_to_int(value): + """Convert an IntEnum member to a numeric value. + If it's not a IntEnum member return the value itself. + """ + try: + return int(value) + except (ValueError, TypeError): + return value + + +@_wraps(_signal.signal) +def signal(signalnum, handler): + handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler)) + return _int_to_enum(handler, Handlers) + + +@_wraps(_signal.getsignal) +def getsignal(signalnum): + handler = _signal.getsignal(signalnum) + return _int_to_enum(handler, Handlers) + + +if 'pthread_sigmask' in _globals: + @_wraps(_signal.pthread_sigmask) + def pthread_sigmask(how, mask): + sigs_set = _signal.pthread_sigmask(how, mask) + return set(_int_to_enum(x, Signals) for x in sigs_set) + pthread_sigmask.__doc__ = _signal.pthread_sigmask.__doc__ + + +if 'sigpending' in _globals: + @_wraps(_signal.sigpending) + def sigpending(): + sigs = _signal.sigpending() + return set(_int_to_enum(x, Signals) for x in sigs) + + +if 'sigwait' in _globals: + @_wraps(_signal.sigwait) + def sigwait(sigset): + retsig = _signal.sigwait(sigset) + return _int_to_enum(retsig, Signals) + sigwait.__doc__ = _signal.sigwait + +del _globals, _wraps diff --git a/Lib/site.py b/Lib/site.py index c0149b4..14f4f80 100644 --- a/Lib/site.py +++ b/Lib/site.py @@ -7,7 +7,7 @@ This will append site-specific paths to the module search path. On Unix (including Mac OSX), it starts with sys.prefix and sys.exec_prefix (if different) and appends -lib/python<version>/site-packages as well as lib/site-python. +lib/python<version>/site-packages. On other platforms (such as Windows), it tries each of the prefixes directly, as well as with lib/site-packages appended. The resulting directories, if they exist, are appended to sys.path, and @@ -15,7 +15,7 @@ also inspected for path configuration files. If a file named "pyvenv.cfg" exists one directory above sys.executable, sys.prefix and sys.exec_prefix are set to that directory and -it is also checked for site-packages and site-python (sys.base_prefix and +it is also checked for site-packages (sys.base_prefix and sys.base_exec_prefix will always be the "real" prefixes of the Python installation). If "pyvenv.cfg" (a bootstrap configuration file) contains the key "include-system-site-packages" set to anything other than "false" @@ -285,8 +285,7 @@ def addusersitepackages(known_paths): return known_paths def getsitepackages(prefixes=None): - """Returns a list containing all global site-packages directories - (and possibly site-python). + """Returns a list containing all global site-packages directories. For each directory present in ``prefixes`` (or the global ``PREFIXES``), this function will find its `site-packages` subdirectory depending on the @@ -307,7 +306,6 @@ def getsitepackages(prefixes=None): sitepackages.append(os.path.join(prefix, "lib", "python" + sys.version[:3], "site-packages")) - sitepackages.append(os.path.join(prefix, "lib", "site-python")) else: sitepackages.append(prefix) sitepackages.append(os.path.join(prefix, "lib", "site-packages")) @@ -323,14 +321,9 @@ def getsitepackages(prefixes=None): return sitepackages def addsitepackages(known_paths, prefixes=None): - """Add site-packages (and possibly site-python) to sys.path""" + """Add site-packages to sys.path""" for sitedir in getsitepackages(prefixes): if os.path.isdir(sitedir): - if "site-python" in sitedir: - import warnings - warnings.warn('"site-python" directories will not be ' - 'supported in 3.5 anymore', - DeprecationWarning) addsitedir(sitedir, known_paths) return known_paths diff --git a/Lib/smtpd.py b/Lib/smtpd.py index 1fa157a..f90fae8 100755 --- a/Lib/smtpd.py +++ b/Lib/smtpd.py @@ -98,7 +98,6 @@ class Devnull: DEBUGSTREAM = Devnull() NEWLINE = '\n' -EMPTYSTRING = '' COMMASPACE = ', ' DATA_SIZE_DEFAULT = 33554432 @@ -122,12 +121,28 @@ class SMTPChannel(asynchat.async_chat): max_command_size_limit = max(command_size_limits.values()) def __init__(self, server, conn, addr, data_size_limit=DATA_SIZE_DEFAULT, - map=None): + map=None, decode_data=None): asynchat.async_chat.__init__(self, conn, map=map) self.smtp_server = server self.conn = conn self.addr = addr self.data_size_limit = data_size_limit + if decode_data is None: + warn("The decode_data default of True will change to False in 3.6;" + " specify an explicit value for this keyword", + DeprecationWarning, 2) + decode_data = True + self._decode_data = decode_data + if decode_data: + self._emptystring = '' + self._linesep = '\r\n' + self._dotsep = '.' + self._newline = NEWLINE + else: + self._emptystring = b'' + self._linesep = b'\r\n' + self._dotsep = b'.' + self._newline = b'\n' self.received_lines = [] self.smtp_state = self.COMMAND self.seen_greeting = '' @@ -287,11 +302,14 @@ class SMTPChannel(asynchat.async_chat): return elif limit: self.num_bytes += len(data) - self.received_lines.append(str(data, "utf-8")) + if self._decode_data: + self.received_lines.append(str(data, 'utf-8')) + else: + self.received_lines.append(data) # Implementation of base class abstract method def found_terminator(self): - line = EMPTYSTRING.join(self.received_lines) + line = self._emptystring.join(self.received_lines) print('Data:', repr(line), file=DEBUGSTREAM) self.received_lines = [] if self.smtp_state == self.COMMAND: @@ -300,6 +318,8 @@ class SMTPChannel(asynchat.async_chat): self.push('500 Error: bad syntax') return method = None + if not self._decode_data: + line = str(line, 'utf-8') i = line.find(' ') if i < 0: command = line.upper() @@ -330,12 +350,12 @@ class SMTPChannel(asynchat.async_chat): # Remove extraneous carriage returns and de-transparency according # to RFC 5321, Section 4.5.2. data = [] - for text in line.split('\r\n'): - if text and text[0] == '.': + for text in line.split(self._linesep): + if text and text[0] == self._dotsep: data.append(text[1:]) else: data.append(text) - self.received_data = NEWLINE.join(data) + self.received_data = self._newline.join(data) status = self.smtp_server.process_message(self.peer, self.mailfrom, self.rcpttos, @@ -577,13 +597,22 @@ class SMTPServer(asyncore.dispatcher): channel_class = SMTPChannel def __init__(self, localaddr, remoteaddr, - data_size_limit=DATA_SIZE_DEFAULT, map=None): + data_size_limit=DATA_SIZE_DEFAULT, map=None, + decode_data=None): self._localaddr = localaddr self._remoteaddr = remoteaddr self.data_size_limit = data_size_limit + if decode_data is None: + warn("The decode_data default of True will change to False in 3.6;" + " specify an explicit value for this keyword", + DeprecationWarning, 2) + decode_data = True + self._decode_data = decode_data asyncore.dispatcher.__init__(self, map=map) try: - self.create_socket(socket.AF_INET, socket.SOCK_STREAM) + gai_results = socket.getaddrinfo(*localaddr, + type=socket.SOCK_STREAM) + self.create_socket(gai_results[0][0], gai_results[0][1]) # try to re-use a server port if possible self.set_reuse_addr() self.bind(localaddr) @@ -599,7 +628,7 @@ class SMTPServer(asyncore.dispatcher): def handle_accepted(self, conn, addr): print('Incoming connection from %s' % repr(addr), file=DEBUGSTREAM) channel = self.channel_class(self, conn, addr, self.data_size_limit, - self._map) + self._map, self._decode_data) # API for "doing something useful with the message" def process_message(self, peer, mailfrom, rcpttos, data): diff --git a/Lib/smtplib.py b/Lib/smtplib.py index 759b77e..e62304a 100755 --- a/Lib/smtplib.py +++ b/Lib/smtplib.py @@ -571,12 +571,60 @@ class SMTP: if not (200 <= code <= 299): raise SMTPHeloError(code, resp) + def auth(self, mechanism, authobject): + """Authentication command - requires response processing. + + 'mechanism' specifies which authentication mechanism is to + be used - the valid values are those listed in the 'auth' + element of 'esmtp_features'. + + 'authobject' must be a callable object taking a single argument: + + data = authobject(challenge) + + It will be called to process the server's challenge response; the + challenge argument it is passed will be a bytes. It should return + bytes data that will be base64 encoded and sent to the server. + """ + + mechanism = mechanism.upper() + (code, resp) = self.docmd("AUTH", mechanism) + # Server replies with 334 (challenge) or 535 (not supported) + if code == 334: + challenge = base64.decodebytes(resp) + response = encode_base64( + authobject(challenge).encode('ascii'), eol='') + (code, resp) = self.docmd(response) + if code in (235, 503): + return (code, resp) + raise SMTPAuthenticationError(code, resp) + + def auth_cram_md5(self, challenge): + """ Authobject to use with CRAM-MD5 authentication. Requires self.user + and self.password to be set.""" + return self.user + " " + hmac.HMAC( + self.password.encode('ascii'), challenge, 'md5').hexdigest() + + def auth_plain(self, challenge): + """ Authobject to use with PLAIN authentication. Requires self.user and + self.password to be set.""" + return "\0%s\0%s" % (self.user, self.password) + + def auth_login(self, challenge): + """ Authobject to use with LOGIN authentication. Requires self.user and + self.password to be set.""" + (code, resp) = self.docmd( + encode_base64(self.user.encode('ascii'), eol='')) + if code == 334: + return self.password + raise SMTPAuthenticationError(code, resp) + def login(self, user, password): """Log in on an SMTP server that requires authentication. The arguments are: - - user: The user name to authenticate with. - - password: The password for the authentication. + - user: The user name to authenticate with. + - password: The password for the authentication. If there has been no previous EHLO or HELO command this session, this method tries ESMTP EHLO first. @@ -593,63 +641,40 @@ class SMTP: found. """ - def encode_cram_md5(challenge, user, password): - challenge = base64.decodebytes(challenge) - response = user + " " + hmac.HMAC(password.encode('ascii'), - challenge, 'md5').hexdigest() - return encode_base64(response.encode('ascii'), eol='') - - def encode_plain(user, password): - s = "\0%s\0%s" % (user, password) - return encode_base64(s.encode('ascii'), eol='') - - AUTH_PLAIN = "PLAIN" - AUTH_CRAM_MD5 = "CRAM-MD5" - AUTH_LOGIN = "LOGIN" - self.ehlo_or_helo_if_needed() - if not self.has_extn("auth"): raise SMTPException("SMTP AUTH extension not supported by server.") # Authentication methods the server claims to support advertised_authlist = self.esmtp_features["auth"].split() - # List of authentication methods we support: from preferred to - # less preferred methods. Except for the purpose of testing the weaker - # ones, we prefer stronger methods like CRAM-MD5: - preferred_auths = [AUTH_CRAM_MD5, AUTH_PLAIN, AUTH_LOGIN] + # Authentication methods we can handle in our preferred order: + preferred_auths = ['CRAM-MD5', 'PLAIN', 'LOGIN'] - # We try the authentication methods the server advertises, but only the - # ones *we* support. And in our preferred order. - authlist = [auth for auth in preferred_auths if auth in advertised_authlist] + # We try the supported authentications in our preferred order, if + # the server supports them. + authlist = [auth for auth in preferred_auths + if auth in advertised_authlist] if not authlist: raise SMTPException("No suitable authentication method found.") # Some servers advertise authentication methods they don't really # support, so if authentication fails, we continue until we've tried # all methods. + self.user, self.password = user, password for authmethod in authlist: - if authmethod == AUTH_CRAM_MD5: - (code, resp) = self.docmd("AUTH", AUTH_CRAM_MD5) - if code == 334: - (code, resp) = self.docmd(encode_cram_md5(resp, user, password)) - elif authmethod == AUTH_PLAIN: - (code, resp) = self.docmd("AUTH", - AUTH_PLAIN + " " + encode_plain(user, password)) - elif authmethod == AUTH_LOGIN: - (code, resp) = self.docmd("AUTH", - "%s %s" % (AUTH_LOGIN, encode_base64(user.encode('ascii'), eol=''))) - if code == 334: - (code, resp) = self.docmd(encode_base64(password.encode('ascii'), eol='')) - - # 235 == 'Authentication successful' - # 503 == 'Error: already authenticated' - if code in (235, 503): - return (code, resp) - - # We could not login sucessfully. Return result of last attempt. - raise SMTPAuthenticationError(code, resp) + method_name = 'auth_' + authmethod.lower().replace('-', '_') + try: + (code, resp) = self.auth(authmethod, getattr(self, method_name)) + # 235 == 'Authentication successful' + # 503 == 'Error: already authenticated' + if code in (235, 503): + return (code, resp) + except SMTPAuthenticationError as e: + last_exception = e + + # We could not login successfully. Return result of last attempt. + raise last_exception def starttls(self, keyfile=None, certfile=None, context=None): """Puts the connection to the SMTP server into TLS mode. diff --git a/Lib/socket.py b/Lib/socket.py index 6d67b3d..cbadff7 100644 --- a/Lib/socket.py +++ b/Lib/socket.py @@ -47,7 +47,7 @@ the setsockopt() and getsockopt() methods. import _socket from _socket import * -import os, sys, io +import os, sys, io, selectors from enum import IntEnum try: @@ -109,6 +109,9 @@ if sys.platform.lower().startswith("win"): __all__.append("errorTab") +class _GiveupOnSendfile(Exception): pass + + class socket(_socket.socket): """A subclass of _socket.socket adding the makefile() method.""" @@ -233,6 +236,149 @@ class socket(_socket.socket): text.mode = mode return text + if hasattr(os, 'sendfile'): + + def _sendfile_use_sendfile(self, file, offset=0, count=None): + self._check_sendfile_params(file, offset, count) + sockno = self.fileno() + try: + fileno = file.fileno() + except (AttributeError, io.UnsupportedOperation) as err: + raise _GiveupOnSendfile(err) # not a regular file + try: + fsize = os.fstat(fileno).st_size + except OSError: + raise _GiveupOnSendfile(err) # not a regular file + if not fsize: + return 0 # empty file + blocksize = fsize if not count else count + + timeout = self.gettimeout() + if timeout == 0: + raise ValueError("non-blocking sockets are not supported") + # poll/select have the advantage of not requiring any + # extra file descriptor, contrarily to epoll/kqueue + # (also, they require a single syscall). + if hasattr(selectors, 'PollSelector'): + selector = selectors.PollSelector() + else: + selector = selectors.SelectSelector() + selector.register(sockno, selectors.EVENT_WRITE) + + total_sent = 0 + # localize variable access to minimize overhead + selector_select = selector.select + os_sendfile = os.sendfile + try: + while True: + if timeout and not selector_select(timeout): + raise _socket.timeout('timed out') + if count: + blocksize = count - total_sent + if blocksize <= 0: + break + try: + sent = os_sendfile(sockno, fileno, offset, blocksize) + except BlockingIOError: + if not timeout: + # Block until the socket is ready to send some + # data; avoids hogging CPU resources. + selector_select() + continue + except OSError as err: + if total_sent == 0: + # We can get here for different reasons, the main + # one being 'file' is not a regular mmap(2)-like + # file, in which case we'll fall back on using + # plain send(). + raise _GiveupOnSendfile(err) + raise err from None + else: + if sent == 0: + break # EOF + offset += sent + total_sent += sent + return total_sent + finally: + if total_sent > 0 and hasattr(file, 'seek'): + file.seek(offset) + else: + def _sendfile_use_sendfile(self, file, offset=0, count=None): + raise _GiveupOnSendfile( + "os.sendfile() not available on this platform") + + def _sendfile_use_send(self, file, offset=0, count=None): + self._check_sendfile_params(file, offset, count) + if self.gettimeout() == 0: + raise ValueError("non-blocking sockets are not supported") + if offset: + file.seek(offset) + blocksize = min(count, 8192) if count else 8192 + total_sent = 0 + # localize variable access to minimize overhead + file_read = file.read + sock_send = self.send + try: + while True: + if count: + blocksize = min(count - total_sent, blocksize) + if blocksize <= 0: + break + data = memoryview(file_read(blocksize)) + if not data: + break # EOF + while True: + try: + sent = sock_send(data) + except BlockingIOError: + continue + else: + total_sent += sent + if sent < len(data): + data = data[sent:] + else: + break + return total_sent + finally: + if total_sent > 0 and hasattr(file, 'seek'): + file.seek(offset + total_sent) + + def _check_sendfile_params(self, file, offset, count): + if 'b' not in getattr(file, 'mode', 'b'): + raise ValueError("file should be opened in binary mode") + if not self.type & SOCK_STREAM: + raise ValueError("only SOCK_STREAM type sockets are supported") + if count is not None: + if not isinstance(count, int): + raise TypeError( + "count must be a positive integer (got {!r})".format(count)) + if count <= 0: + raise ValueError( + "count must be a positive integer (got {!r})".format(count)) + + def sendfile(self, file, offset=0, count=None): + """sendfile(file[, offset[, count]]) -> sent + + Send a file until EOF is reached by using high-performance + os.sendfile() and return the total number of bytes which + were sent. + *file* must be a regular file object opened in binary mode. + If os.sendfile() is not available (e.g. Windows) or file is + not a regular file socket.send() will be used instead. + *offset* tells from where to start reading the file. + If specified, *count* is the total number of bytes to transmit + as opposed to sending the file until EOF is reached. + File position is updated on return or also in case of error in + which case file.tell() can be used to figure out the number of + bytes which were sent. + The socket must be of SOCK_STREAM type. + Non-blocking sockets are not supported. + """ + try: + return self._sendfile_use_sendfile(file, offset, count) + except _GiveupOnSendfile: + return self._sendfile_use_send(file, offset, count) + def _decref_socketios(self): if self._io_refs > 0: self._io_refs -= 1 diff --git a/Lib/socketserver.py b/Lib/socketserver.py index 2f395fa..b585640 100644 --- a/Lib/socketserver.py +++ b/Lib/socketserver.py @@ -94,7 +94,7 @@ handle() method. Another approach to handling multiple simultaneous requests in an environment that supports neither threads nor fork (or where these are too expensive or inappropriate for the service) is to maintain an -explicit table of partially finished requests and to use select() to +explicit table of partially finished requests and to use a selector to decide which request to work on next (or whether to handle a new incoming request). This is particularly important for stream services where each client can potentially be connected for a long time (if @@ -104,7 +104,6 @@ Future work: - Standard classes for Sun RPC (which uses either UDP or TCP) - Standard mix-in classes to implement various authentication and encryption schemes -- Standard framework for select-based multiplexing XXX Open problems: - What to do with out-of-band data? @@ -130,13 +129,17 @@ __version__ = "0.4" import socket -import select +import selectors import os import errno try: import threading except ImportError: import dummy_threading as threading +try: + from time import monotonic as time +except ImportError: + from time import time as time __all__ = ["TCPServer","UDPServer","ForkingUDPServer","ForkingTCPServer", "ThreadingUDPServer","ThreadingTCPServer","BaseRequestHandler", @@ -147,14 +150,13 @@ if hasattr(socket, "AF_UNIX"): "ThreadingUnixStreamServer", "ThreadingUnixDatagramServer"]) -def _eintr_retry(func, *args): - """restart a system call interrupted by EINTR""" - while True: - try: - return func(*args) - except OSError as e: - if e.errno != errno.EINTR: - raise +# poll/select have the advantage of not requiring any extra file descriptor, +# contrarily to epoll/kqueue (also, they require a single syscall). +if hasattr(selectors, 'PollSelector'): + _ServerSelector = selectors.PollSelector +else: + _ServerSelector = selectors.SelectSelector + class BaseServer: @@ -166,7 +168,7 @@ class BaseServer: - serve_forever(poll_interval=0.5) - shutdown() - handle_request() # if you do not use serve_forever() - - fileno() -> int # for select() + - fileno() -> int # for selector Methods that may be overridden: @@ -227,17 +229,19 @@ class BaseServer: """ self.__is_shut_down.clear() try: - while not self.__shutdown_request: - # XXX: Consider using another file descriptor or - # connecting to the socket to wake this up instead of - # polling. Polling reduces our responsiveness to a - # shutdown request and wastes cpu at all other times. - r, w, e = _eintr_retry(select.select, [self], [], [], - poll_interval) - if self in r: - self._handle_request_noblock() - - self.service_actions() + # XXX: Consider using another file descriptor or connecting to the + # socket to wake this up instead of polling. Polling reduces our + # responsiveness to a shutdown request and wastes cpu at all other + # times. + with _ServerSelector() as selector: + selector.register(self, selectors.EVENT_READ) + + while not self.__shutdown_request: + ready = selector.select(poll_interval) + if ready: + self._handle_request_noblock() + + self.service_actions() finally: self.__shutdown_request = False self.__is_shut_down.set() @@ -260,16 +264,16 @@ class BaseServer: """ pass - # The distinction between handling, getting, processing and - # finishing a request is fairly arbitrary. Remember: + # The distinction between handling, getting, processing and finishing a + # request is fairly arbitrary. Remember: # - # - handle_request() is the top-level call. It calls - # select, get_request(), verify_request() and process_request() + # - handle_request() is the top-level call. It calls selector.select(), + # get_request(), verify_request() and process_request() # - get_request() is different for stream or datagram sockets - # - process_request() is the place that may fork a new process - # or create a new thread to finish the request - # - finish_request() instantiates the request handler class; - # this constructor will handle the request all by itself + # - process_request() is the place that may fork a new process or create a + # new thread to finish the request + # - finish_request() instantiates the request handler class; this + # constructor will handle the request all by itself def handle_request(self): """Handle one request, possibly blocking. @@ -283,18 +287,30 @@ class BaseServer: timeout = self.timeout elif self.timeout is not None: timeout = min(timeout, self.timeout) - fd_sets = _eintr_retry(select.select, [self], [], [], timeout) - if not fd_sets[0]: - self.handle_timeout() - return - self._handle_request_noblock() + if timeout is not None: + deadline = time() + timeout + + # Wait until a request arrives or the timeout expires - the loop is + # necessary to accomodate early wakeups due to EINTR. + with _ServerSelector() as selector: + selector.register(self, selectors.EVENT_READ) + + while True: + ready = selector.select(timeout) + if ready: + return self._handle_request_noblock() + else: + if timeout is not None: + timeout = deadline - time() + if timeout < 0: + return self.handle_timeout() def _handle_request_noblock(self): """Handle one request, without blocking. - I assume that select.select has returned that the socket is - readable before this function was called, so there should be - no risk of blocking in get_request(). + I assume that selector.select() has returned that the socket is + readable before this function was called, so there should be no risk of + blocking in get_request(). """ try: request, client_address = self.get_request() @@ -377,7 +393,7 @@ class TCPServer(BaseServer): - serve_forever(poll_interval=0.5) - shutdown() - handle_request() # if you don't use serve_forever() - - fileno() -> int # for select() + - fileno() -> int # for selector Methods that may be overridden: @@ -459,7 +475,7 @@ class TCPServer(BaseServer): def fileno(self): """Return socket file number. - Interface required by select(). + Interface required by selector. """ return self.socket.fileno() @@ -92,7 +92,7 @@ import re import sys import os from collections import namedtuple -from enum import Enum as _Enum +from enum import Enum as _Enum, IntEnum as _IntEnum import _ssl # if we can't import it, let the error propagate @@ -119,30 +119,19 @@ _import_symbols('SSL_ERROR_') from _ssl import HAS_SNI, HAS_ECDH, HAS_NPN -from _ssl import PROTOCOL_SSLv3, PROTOCOL_SSLv23, PROTOCOL_TLSv1 from _ssl import _OPENSSL_API_VERSION +_SSLMethod = _IntEnum('_SSLMethod', + {name: value for name, value in vars(_ssl).items() + if name.startswith('PROTOCOL_')}) +globals().update(_SSLMethod.__members__) + +_PROTOCOL_NAMES = {value: name for name, value in _SSLMethod.__members__.items()} -_PROTOCOL_NAMES = { - PROTOCOL_TLSv1: "TLSv1", - PROTOCOL_SSLv23: "SSLv23", - PROTOCOL_SSLv3: "SSLv3", -} try: - from _ssl import PROTOCOL_SSLv2 _SSLv2_IF_EXISTS = PROTOCOL_SSLv2 -except ImportError: +except NameError: _SSLv2_IF_EXISTS = None -else: - _PROTOCOL_NAMES[PROTOCOL_SSLv2] = "SSLv2" - -try: - from _ssl import PROTOCOL_TLSv1_1, PROTOCOL_TLSv1_2 -except ImportError: - pass -else: - _PROTOCOL_NAMES[PROTOCOL_TLSv1_1] = "TLSv1.1" - _PROTOCOL_NAMES[PROTOCOL_TLSv1_2] = "TLSv1.2" if sys.platform == "win32": from _ssl import enum_certificates, enum_crls @@ -675,17 +664,7 @@ class SSLSocket(socket): raise ValueError( "non-zero flags not allowed in calls to send() on %s" % self.__class__) - try: - v = self._sslobj.write(data) - except SSLError as x: - if x.args[0] == SSL_ERROR_WANT_READ: - return 0 - elif x.args[0] == SSL_ERROR_WANT_WRITE: - return 0 - else: - raise - else: - return v + return self._sslobj.write(data) else: return socket.send(self, data, flags) @@ -721,6 +700,16 @@ class SSLSocket(socket): else: return socket.sendall(self, data, flags) + def sendfile(self, file, offset=0, count=None): + """Send a file, possibly by using os.sendfile() if this is a + clear-text socket. Return the total number of bytes sent. + """ + if self._sslobj is None: + # os.sendfile() works with plain sockets only + return super().sendfile(file, offset, count) + else: + return self._sendfile_use_send(file, offset, count) + def recv(self, buflen=1024, flags=0): self._checkClosed() if self._sslobj: @@ -890,12 +879,34 @@ def wrap_socket(sock, keyfile=None, certfile=None, # some utility functions def cert_time_to_seconds(cert_time): - """Takes a date-time string in standard ASN1_print form - ("MON DAY 24HOUR:MINUTE:SEC YEAR TIMEZONE") and return - a Python time value in seconds past the epoch.""" + """Return the time in seconds since the Epoch, given the timestring + representing the "notBefore" or "notAfter" date from a certificate + in ``"%b %d %H:%M:%S %Y %Z"`` strptime format (C locale). - import time - return time.mktime(time.strptime(cert_time, "%b %d %H:%M:%S %Y GMT")) + "notBefore" or "notAfter" dates must use UTC (RFC 5280). + + Month is one of: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec + UTC should be specified as GMT (see ASN1_TIME_print()) + """ + from time import strptime + from calendar import timegm + + months = ( + "Jan","Feb","Mar","Apr","May","Jun", + "Jul","Aug","Sep","Oct","Nov","Dec" + ) + time_format = ' %d %H:%M:%S %Y GMT' # NOTE: no month, fixed GMT + try: + month_number = months.index(cert_time[:3].title()) + 1 + except ValueError: + raise ValueError('time data %r does not match ' + 'format "%%b%s"' % (cert_time, time_format)) + else: + # found valid month + tt = strptime(cert_time[3:], time_format) + # return an integer, the previous mktime()-based implementation + # returned a float (fractional seconds are always zero here). + return timegm((tt[0], month_number) + tt[2:6]) PEM_HEADER = "-----BEGIN CERTIFICATE-----" PEM_FOOTER = "-----END CERTIFICATE-----" @@ -922,7 +933,7 @@ def PEM_cert_to_DER_cert(pem_cert_string): d = pem_cert_string.strip()[len(PEM_HEADER):-len(PEM_FOOTER)] return base64.decodebytes(d.encode('ASCII', 'strict')) -def get_server_certificate(addr, ssl_version=PROTOCOL_SSLv3, ca_certs=None): +def get_server_certificate(addr, ssl_version=PROTOCOL_SSLv23, ca_certs=None): """Retrieve the certificate from the server at the specified address, and return it as a PEM-encoded string. If 'ca_certs' is specified, validate the server cert against it. diff --git a/Lib/stat.py b/Lib/stat.py index 3eecc3e..46837c0 100644 --- a/Lib/stat.py +++ b/Lib/stat.py @@ -148,6 +148,29 @@ def filemode(mode): perm.append("-") return "".join(perm) + +# Windows FILE_ATTRIBUTE constants for interpreting os.stat()'s +# "st_file_attributes" member + +FILE_ATTRIBUTE_ARCHIVE = 32 +FILE_ATTRIBUTE_COMPRESSED = 2048 +FILE_ATTRIBUTE_DEVICE = 64 +FILE_ATTRIBUTE_DIRECTORY = 16 +FILE_ATTRIBUTE_ENCRYPTED = 16384 +FILE_ATTRIBUTE_HIDDEN = 2 +FILE_ATTRIBUTE_INTEGRITY_STREAM = 32768 +FILE_ATTRIBUTE_NORMAL = 128 +FILE_ATTRIBUTE_NOT_CONTENT_INDEXED = 8192 +FILE_ATTRIBUTE_NO_SCRUB_DATA = 131072 +FILE_ATTRIBUTE_OFFLINE = 4096 +FILE_ATTRIBUTE_READONLY = 1 +FILE_ATTRIBUTE_REPARSE_POINT = 1024 +FILE_ATTRIBUTE_SPARSE_FILE = 512 +FILE_ATTRIBUTE_SYSTEM = 4 +FILE_ATTRIBUTE_TEMPORARY = 256 +FILE_ATTRIBUTE_VIRTUAL = 65536 + + # If available, use C implementation try: from _stat import * diff --git a/Lib/subprocess.py b/Lib/subprocess.py index ddc033a..49aa6ab 100644 --- a/Lib/subprocess.py +++ b/Lib/subprocess.py @@ -104,17 +104,21 @@ in the child process prior to executing the command. If env is not None, it defines the environment variables for the new process. -If universal_newlines is false, the file objects stdin, stdout and stderr +If universal_newlines is False, the file objects stdin, stdout and stderr are opened as binary files, and no line ending conversion is done. -If universal_newlines is true, the file objects stdout and stderr are -opened as a text files, but lines may be terminated by any of '\n', +If universal_newlines is True, the file objects stdout and stderr are +opened as a text file, but lines may be terminated by any of '\n', the Unix end-of-line convention, '\r', the old Macintosh convention or '\r\n', the Windows convention. All of these external representations are seen as '\n' by the Python program. Also, the newlines attribute of the file objects stdout, stdin and stderr are not updated by the communicate() method. +In either case, the process being communicated with should start up +expecting to receive bytes on its standard input and decode them with +the same encoding they are sent in. + The startupinfo and creationflags, if given, will be passed to the underlying CreateProcess() function. They can specify things such as appearance of the main window and priority for the new process. @@ -184,6 +188,9 @@ check_output(*popenargs, **kwargs): pass a string to the subprocess's stdin. If you use this argument you may not also use the Popen constructor's "stdin" argument. + If universal_newlines is set to True, the "input" argument must + be a string rather than bytes, and the return value will be a string. + Exceptions ---------- Exceptions raised in the child process, before the new program has @@ -225,9 +232,13 @@ wait() communicate(input=None) Interact with process: Send data to stdin. Read data from stdout and stderr, until end-of-file is reached. Wait for process to - terminate. The optional input argument should be a string to be + terminate. The optional input argument should be data to be sent to the child process, or None, if no data should be sent to - the child. + the child. If the Popen instance was constructed with universal_newlines + set to True, the input argument should be a string and will be encoded + using the preferred system encoding (see locale.getpreferredencoding); + if universal_newlines is False, the input argument should be a + byte string. communicate() returns a tuple (stdout, stderr). @@ -458,10 +469,6 @@ if mswindows: __del__ = Close __str__ = __repr__ -try: - MAXFD = os.sysconf("SC_OPEN_MAX") -except: - MAXFD = 256 # This lists holds Popen instances for which the underlying process had not # exited at the time its __del__ method got called: those processes are wait()ed @@ -591,8 +598,8 @@ def check_output(*popenargs, timeout=None, **kwargs): ... input=b"when in the course of fooman events\n") b'when in the course of barman events\n' - If universal_newlines=True is passed, the return value will be a - string rather than bytes. + If universal_newlines=True is passed, the "input" argument must be a + string and the return value will be a string rather than bytes. """ if 'stdout' in kwargs: raise ValueError('stdout argument not allowed, it will be overridden.') @@ -918,11 +925,16 @@ class Popen(object): def communicate(self, input=None, timeout=None): """Interact with process: Send data to stdin. Read data from stdout and stderr, until end-of-file is reached. Wait for - process to terminate. The optional input argument should be - bytes to be sent to the child process, or None, if no data - should be sent to the child. + process to terminate. - communicate() returns a tuple (stdout, stderr).""" + The optional "input" argument should be data to be sent to the + child process (if self.universal_newlines is True, this should + be a string; if it is False, "input" should be bytes), or + None, if no data should be sent to the child. + + communicate() returns a tuple (stdout, stderr). These will be + bytes or, if self.universal_newlines was True, a string. + """ if self._communication_started and input: raise ValueError("Cannot send input after starting communication") @@ -1319,16 +1331,6 @@ class Popen(object): errread, errwrite) - def _close_fds(self, fds_to_keep): - start_fd = 3 - for fd in sorted(fds_to_keep): - if fd >= start_fd: - os.closerange(start_fd, fd) - start_fd = fd + 1 - if start_fd <= MAXFD: - os.closerange(start_fd, MAXFD) - - def _execute_child(self, args, executable, preexec_fn, close_fds, pass_fds, cwd, env, startupinfo, creationflags, shell, diff --git a/Lib/tempfile.py b/Lib/tempfile.py index f0e25fc..5d9c719 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -473,6 +473,11 @@ if _os.name != 'posix' or _os.sys.platform == 'cygwin': TemporaryFile = NamedTemporaryFile else: + # Is the O_TMPFILE flag available and does it work? + # The flag is set to False if os.open(dir, os.O_TMPFILE) raises an + # IsADirectoryError exception + _O_TMPFILE_WORKS = hasattr(_os, 'O_TMPFILE') + def TemporaryFile(mode='w+b', buffering=-1, encoding=None, newline=None, suffix="", prefix=template, dir=None): @@ -488,11 +493,32 @@ else: Returns an object with a file-like interface. The file has no name, and will cease to exist when it is closed. """ + global _O_TMPFILE_WORKS if dir is None: dir = gettempdir() flags = _bin_openflags + if _O_TMPFILE_WORKS: + try: + flags2 = (flags | _os.O_TMPFILE) & ~_os.O_CREAT + fd = _os.open(dir, flags2, 0o600) + except IsADirectoryError: + # Linux kernel older than 3.11 ignores O_TMPFILE flag. + # Set flag to False to not try again. + _O_TMPFILE_WORKS = False + except OSError: + # The filesystem of the directory does not support O_TMPFILE. + # For example, OSError(95, 'Operation not supported'). + pass + else: + try: + return _io.open(fd, mode, buffering=buffering, + newline=newline, encoding=encoding) + except: + _os.close(fd) + raise + # Fallback to _mkstemp_inner(). (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags) try: diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py index 3f3c60a..b8c6138 100644 --- a/Lib/test/datetimetester.py +++ b/Lib/test/datetimetester.py @@ -2270,13 +2270,14 @@ class TestTime(HarmlessMixedComparison, unittest.TestCase): self.assertEqual(orig, derived) def test_bool(self): + # time is always True. cls = self.theclass self.assertTrue(cls(1)) self.assertTrue(cls(0, 1)) self.assertTrue(cls(0, 0, 1)) self.assertTrue(cls(0, 0, 0, 1)) - self.assertFalse(cls(0)) - self.assertFalse(cls()) + self.assertTrue(cls(0)) + self.assertTrue(cls()) def test_replace(self): cls = self.theclass @@ -2629,7 +2630,7 @@ class TestTimeTZ(TestTime, TZInfoBase, unittest.TestCase): self.assertEqual(derived.tzname(), 'cookie') def test_more_bool(self): - # Test cases with non-None tzinfo. + # time is always True. cls = self.theclass t = cls(0, tzinfo=FixedOffset(-300, "")) @@ -2639,23 +2640,11 @@ class TestTimeTZ(TestTime, TZInfoBase, unittest.TestCase): self.assertTrue(t) t = cls(5, tzinfo=FixedOffset(300, "")) - self.assertFalse(t) + self.assertTrue(t) t = cls(23, 59, tzinfo=FixedOffset(23*60 + 59, "")) - self.assertFalse(t) - - # Mostly ensuring this doesn't overflow internally. - t = cls(0, tzinfo=FixedOffset(23*60 + 59, "")) self.assertTrue(t) - # But this should yield a value error -- the utcoffset is bogus. - t = cls(0, tzinfo=FixedOffset(24*60, "")) - self.assertRaises(ValueError, lambda: bool(t)) - - # Likewise. - t = cls(0, tzinfo=FixedOffset(-24*60, "")) - self.assertRaises(ValueError, lambda: bool(t)) - def test_replace(self): cls = self.theclass z100 = FixedOffset(100, "+100") diff --git a/Lib/test/fork_wait.py b/Lib/test/fork_wait.py index 19b54ec..8c7c3aa 100644 --- a/Lib/test/fork_wait.py +++ b/Lib/test/fork_wait.py @@ -48,7 +48,12 @@ class ForkWait(unittest.TestCase): for i in range(NUM_THREADS): _thread.start_new(self.f, (i,)) - time.sleep(LONGSLEEP) + # busy-loop to wait for threads + deadline = time.monotonic() + 10.0 + while len(self.alive) < NUM_THREADS: + time.sleep(0.1) + if time.monotonic() <= deadline: + break a = sorted(self.alive.keys()) self.assertEqual(a, list(range(NUM_THREADS))) diff --git a/Lib/test/imghdrdata/python.exr b/Lib/test/imghdrdata/python.exr Binary files differnew file mode 100644 index 0000000..773c81e --- /dev/null +++ b/Lib/test/imghdrdata/python.exr diff --git a/Lib/test/imghdrdata/python.webp b/Lib/test/imghdrdata/python.webp Binary files differnew file mode 100644 index 0000000..e824ec7 --- /dev/null +++ b/Lib/test/imghdrdata/python.webp diff --git a/Lib/test/lock_tests.py b/Lib/test/lock_tests.py index 1cbcea2..136f1c3 100644 --- a/Lib/test/lock_tests.py +++ b/Lib/test/lock_tests.py @@ -82,7 +82,13 @@ class BaseLockTests(BaseTestCase): def test_repr(self): lock = self.locktype() - repr(lock) + self.assertRegex(repr(lock), "<unlocked .* object (.*)?at .*>") + del lock + + def test_locked_repr(self): + lock = self.locktype() + lock.acquire() + self.assertRegex(repr(lock), "<locked .* object (.*)?at .*>") del lock def test_acquire_destroy(self): diff --git a/Lib/test/mock_socket.py b/Lib/test/mock_socket.py index e36724f..441e29f 100644 --- a/Lib/test/mock_socket.py +++ b/Lib/test/mock_socket.py @@ -35,8 +35,9 @@ class MockFile: class MockSocket: """Mock socket object used by smtpd and smtplib tests. """ - def __init__(self): + def __init__(self, family=None): global _reply_data + self.family = family self.output = [] self.lines = [] if _reply_data: @@ -108,8 +109,7 @@ class MockSocket: def socket(family=None, type=None, proto=None): - return MockSocket() - + return MockSocket(family) def create_connection(address, timeout=socket_module._GLOBAL_DEFAULT_TIMEOUT, source_address=None): @@ -144,13 +144,16 @@ def gethostname(): def gethostbyname(name): return "" +def getaddrinfo(*args, **kw): + return socket_module.getaddrinfo(*args, **kw) gaierror = socket_module.gaierror error = socket_module.error # Constants -AF_INET = None -SOCK_STREAM = None +AF_INET = socket_module.AF_INET +AF_INET6 = socket_module.AF_INET6 +SOCK_STREAM = socket_module.SOCK_STREAM SOL_SOCKET = None SO_REUSEADDR = None diff --git a/Lib/test/pystone.py b/Lib/test/pystone.py index a41f1e5..1f67e66 100755 --- a/Lib/test/pystone.py +++ b/Lib/test/pystone.py @@ -41,7 +41,7 @@ Version History: LOOPS = 50000 -from time import clock +from time import time __version__ = "1.2" @@ -93,10 +93,10 @@ def Proc0(loops=LOOPS): global PtrGlb global PtrGlbNext - starttime = clock() + starttime = time() for i in range(loops): pass - nulltime = clock() - starttime + nulltime = time() - starttime PtrGlbNext = Record() PtrGlb = Record() @@ -108,7 +108,7 @@ def Proc0(loops=LOOPS): String1Loc = "DHRYSTONE PROGRAM, 1'ST STRING" Array2Glob[8][7] = 10 - starttime = clock() + starttime = time() for i in range(loops): Proc5() @@ -134,7 +134,7 @@ def Proc0(loops=LOOPS): IntLoc2 = 7 * (IntLoc3 - IntLoc2) - IntLoc1 IntLoc1 = Proc2(IntLoc1) - benchtime = clock() - starttime - nulltime + benchtime = time() - starttime - nulltime if benchtime == 0.0: loopsPerBenchtime = 0.0 else: diff --git a/Lib/test/ssl_servers.py b/Lib/test/ssl_servers.py index 759b3f4..f9d30cf 100644 --- a/Lib/test/ssl_servers.py +++ b/Lib/test/ssl_servers.py @@ -150,7 +150,7 @@ class HTTPSServerThread(threading.Thread): def make_https_server(case, *, context=None, certfile=CERTFILE, host=HOST, handler_class=None): if context is None: - context = ssl.SSLContext(ssl.PROTOCOL_SSLv23) + context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH) # We assume the certfile contains both private key and certificate context.load_cert_chain(certfile) server = HTTPSServerThread(context, host, handler_class) @@ -182,6 +182,8 @@ if __name__ == "__main__": parser.add_argument('--curve-name', dest='curve_name', type=str, action='store', help='curve name for EC-based Diffie-Hellman') + parser.add_argument('--ciphers', dest='ciphers', type=str, + help='allowed cipher list') parser.add_argument('--dh', dest='dh_file', type=str, action='store', help='PEM file containing DH parameters') args = parser.parse_args() @@ -192,12 +194,14 @@ if __name__ == "__main__": else: handler_class = RootedHTTPRequestHandler handler_class.root = os.getcwd() - context = ssl.SSLContext(ssl.PROTOCOL_TLSv1) + context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH) context.load_cert_chain(CERTFILE) if args.curve_name: context.set_ecdh_curve(args.curve_name) if args.dh_file: context.load_dh_params(args.dh_file) + if args.ciphers: + context.set_ciphers(args.ciphers) server = HTTPSServer(("", args.port), handler_class, context) if args.verbose: diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py index 5ed01f2..569bae1 100644 --- a/Lib/test/string_tests.py +++ b/Lib/test/string_tests.py @@ -1178,8 +1178,7 @@ class MixinStrUnicodeUserStringTest: self.checkraises(TypeError, 'abc', '__mod__') self.checkraises(TypeError, '%(foo)s', '__mod__', 42) self.checkraises(TypeError, '%s%s', '__mod__', (42,)) - with self.assertWarns(DeprecationWarning): - self.checkraises(TypeError, '%c', '__mod__', (None,)) + self.checkraises(TypeError, '%c', '__mod__', (None,)) self.checkraises(ValueError, '%(foo', '__mod__', {}) self.checkraises(TypeError, '%(foo)s %(bar)s', '__mod__', ('foo', 42)) self.checkraises(TypeError, '%d', '__mod__', "42") # not numeric diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py index 8a4fdb9..e4c9c38 100644 --- a/Lib/test/test_argparse.py +++ b/Lib/test/test_argparse.py @@ -20,15 +20,6 @@ class StdIOBuffer(StringIO): class TestCase(unittest.TestCase): - def assertEqual(self, obj1, obj2): - if obj1 != obj2: - print('') - print(repr(obj1)) - print(repr(obj2)) - print(obj1) - print(obj2) - super(TestCase, self).assertEqual(obj1, obj2) - def setUp(self): # The tests assume that line wrapping occurs at 80 columns, but this # behaviour can be overridden by setting the COLUMNS environment @@ -1993,14 +1984,9 @@ class TestAddSubparsers(TestCase): ''')) def _test_subparser_help(self, args_str, expected_help): - try: + with self.assertRaises(ArgumentParserError) as cm: self.parser.parse_args(args_str.split()) - except ArgumentParserError: - err = sys.exc_info()[1] - if err.stdout != expected_help: - print(repr(expected_help)) - print(repr(err.stdout)) - self.assertEqual(err.stdout, expected_help) + self.assertEqual(expected_help, cm.exception.stdout) def test_subparser1_help(self): self._test_subparser_help('5.0 1 -h', textwrap.dedent('''\ @@ -2839,15 +2825,15 @@ class TestGetDefault(TestCase): def test_get_default(self): parser = ErrorRaisingArgumentParser() - self.assertEqual(None, parser.get_default("foo")) - self.assertEqual(None, parser.get_default("bar")) + self.assertIsNone(parser.get_default("foo")) + self.assertIsNone(parser.get_default("bar")) parser.add_argument("--foo") - self.assertEqual(None, parser.get_default("foo")) - self.assertEqual(None, parser.get_default("bar")) + self.assertIsNone(parser.get_default("foo")) + self.assertIsNone(parser.get_default("bar")) parser.add_argument("--bar", type=int, default=42) - self.assertEqual(None, parser.get_default("foo")) + self.assertIsNone(parser.get_default("foo")) self.assertEqual(42, parser.get_default("bar")) parser.set_defaults(foo="badger") @@ -2862,18 +2848,16 @@ class TestNamespaceContainsSimple(TestCase): def test_empty(self): ns = argparse.Namespace() - self.assertEqual('' in ns, False) - self.assertEqual('' not in ns, True) - self.assertEqual('x' in ns, False) + self.assertNotIn('', ns) + self.assertNotIn('x', ns) def test_non_empty(self): ns = argparse.Namespace(x=1, y=2) - self.assertEqual('x' in ns, True) - self.assertEqual('x' not in ns, False) - self.assertEqual('y' in ns, True) - self.assertEqual('' in ns, False) - self.assertEqual('xx' in ns, False) - self.assertEqual('z' in ns, False) + self.assertNotIn('', ns) + self.assertIn('x', ns) + self.assertIn('y', ns) + self.assertNotIn('xx', ns) + self.assertNotIn('z', ns) # ===================== # Help formatting tests @@ -2929,13 +2913,6 @@ class TestHelpFormattingMetaclass(type): def _test(self, tester, parser_text): expected_text = getattr(tester, self.func_suffix) expected_text = textwrap.dedent(expected_text) - if expected_text != parser_text: - print(repr(expected_text)) - print(repr(parser_text)) - for char1, char2 in zip(expected_text, parser_text): - if char1 != char2: - print('first diff: %r %r' % (char1, char2)) - break tester.assertEqual(expected_text, parser_text) def test_format(self, tester): @@ -4216,24 +4193,17 @@ class TestInvalidArgumentConstructors(TestCase): self.assertValueError('foo', action='baz') self.assertValueError('--foo', action=('store', 'append')) parser = argparse.ArgumentParser() - try: + with self.assertRaises(ValueError) as cm: parser.add_argument("--foo", action="store-true") - except ValueError: - e = sys.exc_info()[1] - expected = 'unknown action' - msg = 'expected %r, found %r' % (expected, e) - self.assertTrue(expected in str(e), msg) + self.assertIn('unknown action', str(cm.exception)) def test_multiple_dest(self): parser = argparse.ArgumentParser() parser.add_argument(dest='foo') - try: + with self.assertRaises(ValueError) as cm: parser.add_argument('bar', dest='baz') - except ValueError: - e = sys.exc_info()[1] - expected = 'dest supplied twice for positional argument' - msg = 'expected %r, found %r' % (expected, e) - self.assertTrue(expected in str(e), msg) + self.assertIn('dest supplied twice for positional argument', + str(cm.exception)) def test_no_argument_actions(self): for action in ['store_const', 'store_true', 'store_false', @@ -4390,18 +4360,10 @@ class TestConflictHandling(TestCase): class TestOptionalsHelpVersionActions(TestCase): """Test the help and version actions""" - def _get_error(self, func, *args, **kwargs): - try: - func(*args, **kwargs) - except ArgumentParserError: - return sys.exc_info()[1] - else: - self.assertRaises(ArgumentParserError, func, *args, **kwargs) - def assertPrintHelpExit(self, parser, args_str): - self.assertEqual( - parser.format_help(), - self._get_error(parser.parse_args, args_str.split()).stdout) + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args(args_str.split()) + self.assertEqual(parser.format_help(), cm.exception.stdout) def assertArgumentParserError(self, parser, *args): self.assertRaises(ArgumentParserError, parser.parse_args, args) @@ -4416,8 +4378,9 @@ class TestOptionalsHelpVersionActions(TestCase): def test_version_format(self): parser = ErrorRaisingArgumentParser(prog='PPP') parser.add_argument('-v', '--version', action='version', version='%(prog)s 3.5') - msg = self._get_error(parser.parse_args, ['-v']).stdout - self.assertEqual('PPP 3.5\n', msg) + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args(['-v']) + self.assertEqual('PPP 3.5\n', cm.exception.stdout) def test_version_no_help(self): parser = ErrorRaisingArgumentParser(add_help=False) @@ -4429,8 +4392,9 @@ class TestOptionalsHelpVersionActions(TestCase): def test_version_action(self): parser = ErrorRaisingArgumentParser(prog='XXX') parser.add_argument('-V', action='version', version='%(prog)s 3.7') - msg = self._get_error(parser.parse_args, ['-V']).stdout - self.assertEqual('XXX 3.7\n', msg) + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args(['-V']) + self.assertEqual('XXX 3.7\n', cm.exception.stdout) def test_no_help(self): parser = ErrorRaisingArgumentParser(add_help=False) @@ -4600,14 +4564,10 @@ class TestArgumentTypeError(TestCase): parser = ErrorRaisingArgumentParser(prog='PROG', add_help=False) parser.add_argument('x', type=spam) - try: + with self.assertRaises(ArgumentParserError) as cm: parser.parse_args(['XXX']) - except ArgumentParserError: - expected = 'usage: PROG x\nPROG: error: argument x: spam!\n' - msg = sys.exc_info()[1].stderr - self.assertEqual(expected, msg) - else: - self.fail() + self.assertEqual('usage: PROG x\nPROG: error: argument x: spam!\n', + cm.exception.stderr) # ========================= # MessageContentError tests diff --git a/Lib/test/test_asdl_parser.py b/Lib/test/test_asdl_parser.py new file mode 100644 index 0000000..7a6426a --- /dev/null +++ b/Lib/test/test_asdl_parser.py @@ -0,0 +1,122 @@ +"""Tests for the asdl parser in Parser/asdl.py""" + +import importlib.machinery +import os +from os.path import dirname +import sys +import sysconfig +import unittest + + +# This test is only relevant for from-source builds of Python. +if not sysconfig.is_python_build(): + raise unittest.SkipTest('test irrelevant for an installed Python') + +src_base = dirname(dirname(dirname(__file__))) +parser_dir = os.path.join(src_base, 'Parser') + + +class TestAsdlParser(unittest.TestCase): + @classmethod + def setUpClass(cls): + # Loads the asdl module dynamically, since it's not in a real importable + # package. + # Parses Python.asdl into a ast.Module and run the check on it. + # There's no need to do this for each test method, hence setUpClass. + sys.path.insert(0, parser_dir) + loader = importlib.machinery.SourceFileLoader( + 'asdl', os.path.join(parser_dir, 'asdl.py')) + cls.asdl = loader.load_module() + cls.mod = cls.asdl.parse(os.path.join(parser_dir, 'Python.asdl')) + cls.assertTrue(cls.asdl.check(cls.mod), 'Module validation failed') + + @classmethod + def tearDownClass(cls): + del sys.path[0] + + def setUp(self): + # alias stuff from the class, for convenience + self.asdl = TestAsdlParser.asdl + self.mod = TestAsdlParser.mod + self.types = self.mod.types + + def test_module(self): + self.assertEqual(self.mod.name, 'Python') + self.assertIn('stmt', self.types) + self.assertIn('expr', self.types) + self.assertIn('mod', self.types) + + def test_definitions(self): + defs = self.mod.dfns + self.assertIsInstance(defs[0], self.asdl.Type) + self.assertIsInstance(defs[0].value, self.asdl.Sum) + + self.assertIsInstance(self.types['withitem'], self.asdl.Product) + self.assertIsInstance(self.types['alias'], self.asdl.Product) + + def test_product(self): + alias = self.types['alias'] + self.assertEqual( + str(alias), + 'Product([Field(identifier, name), Field(identifier, asname, opt=True)])') + + def test_attributes(self): + stmt = self.types['stmt'] + self.assertEqual(len(stmt.attributes), 2) + self.assertEqual(str(stmt.attributes[0]), 'Field(int, lineno)') + self.assertEqual(str(stmt.attributes[1]), 'Field(int, col_offset)') + + def test_constructor_fields(self): + ehandler = self.types['excepthandler'] + self.assertEqual(len(ehandler.types), 1) + self.assertEqual(len(ehandler.attributes), 2) + + cons = ehandler.types[0] + self.assertIsInstance(cons, self.asdl.Constructor) + self.assertEqual(len(cons.fields), 3) + + f0 = cons.fields[0] + self.assertEqual(f0.type, 'expr') + self.assertEqual(f0.name, 'type') + self.assertTrue(f0.opt) + + f1 = cons.fields[1] + self.assertEqual(f1.type, 'identifier') + self.assertEqual(f1.name, 'name') + self.assertTrue(f1.opt) + + f2 = cons.fields[2] + self.assertEqual(f2.type, 'stmt') + self.assertEqual(f2.name, 'body') + self.assertFalse(f2.opt) + self.assertTrue(f2.seq) + + def test_visitor(self): + class CustomVisitor(self.asdl.VisitorBase): + def __init__(self): + super().__init__() + self.names_with_seq = [] + + def visitModule(self, mod): + for dfn in mod.dfns: + self.visit(dfn) + + def visitType(self, type): + self.visit(type.value) + + def visitSum(self, sum): + for t in sum.types: + self.visit(t) + + def visitConstructor(self, cons): + for f in cons.fields: + if f.seq: + self.names_with_seq.append(cons.name) + + v = CustomVisitor() + v.visit(self.types['mod']) + self.assertEqual(v.names_with_seq, ['Module', 'Interactive', 'Suite']) + + +if __name__ == '__main__': + unittest.main() diff --git a/Lib/test/test_asynchat.py b/Lib/test/test_asynchat.py index 84867ec..fd64adc 100644 --- a/Lib/test/test_asynchat.py +++ b/Lib/test/test_asynchat.py @@ -11,6 +11,7 @@ import socket import sys import time import unittest +import warnings try: import threading except ImportError: @@ -281,7 +282,10 @@ class TestHelperFunctions(unittest.TestCase): class TestFifo(unittest.TestCase): def test_basic(self): - f = asynchat.fifo() + with self.assertWarns(DeprecationWarning) as cm: + f = asynchat.fifo() + self.assertEqual(str(cm.warning), + "fifo class will be removed in Python 3.6") f.push(7) f.push(b'a') self.assertEqual(len(f), 2) @@ -296,7 +300,10 @@ class TestFifo(unittest.TestCase): self.assertEqual(f.pop(), (0, None)) def test_given_list(self): - f = asynchat.fifo([b'x', 17, 3]) + with self.assertWarns(DeprecationWarning) as cm: + f = asynchat.fifo([b'x', 17, 3]) + self.assertEqual(str(cm.warning), + "fifo class will be removed in Python 3.6") self.assertEqual(len(f), 3) self.assertEqual(f.pop(), (1, b'x')) self.assertEqual(f.pop(), (1, 17)) diff --git a/Lib/test/test_asyncio/test_streams.py b/Lib/test/test_asyncio/test_streams.py index 73a375a..8adc3b2 100644 --- a/Lib/test/test_asyncio/test_streams.py +++ b/Lib/test/test_asyncio/test_streams.py @@ -596,6 +596,12 @@ class StreamReaderTests(test_utils.TestCase): code = """\ import os, sys +try: + import faulthandler +except ImportError: + pass +else: + faulthandler.dump_traceback_later(60, exit=True) fd = int(sys.argv[1]) os.write(fd, b'data') os.close(fd) diff --git a/Lib/test/test_asyncore.py b/Lib/test/test_asyncore.py index 6cfe580..b4f474f 100644 --- a/Lib/test/test_asyncore.py +++ b/Lib/test/test_asyncore.py @@ -7,7 +7,6 @@ import sys import time import errno import struct -import warnings from test import support from io import BytesIO @@ -298,23 +297,6 @@ class DispatcherTests(unittest.TestCase): 'warning: unhandled connect event'] self.assertEqual(lines, expected) - def test_issue_8594(self): - # XXX - this test is supposed to be removed in next major Python - # version - d = asyncore.dispatcher(socket.socket()) - # make sure the error message no longer refers to the socket - # object but the dispatcher instance instead - self.assertRaisesRegex(AttributeError, 'dispatcher instance', - getattr, d, 'foo') - # cheap inheritance with the underlying socket is supposed - # to still work but a DeprecationWarning is expected - with warnings.catch_warnings(record=True) as w: - warnings.simplefilter("always") - family = d.family - self.assertEqual(family, socket.AF_INET) - self.assertEqual(len(w), 1) - self.assertTrue(issubclass(w[0].category, DeprecationWarning)) - def test_strerror(self): # refers to bug #8573 err = asyncore._strerror(errno.EPERM) @@ -331,9 +313,8 @@ class dispatcherwithsend_noread(asyncore.dispatcher_with_send): def handle_connect(self): pass -class DispatcherWithSendTests(unittest.TestCase): - usepoll = False +class DispatcherWithSendTests(unittest.TestCase): def setUp(self): pass @@ -383,10 +364,6 @@ class DispatcherWithSendTests(unittest.TestCase): self.fail("join() timed out") - -class DispatcherWithSendTests_UsePoll(DispatcherWithSendTests): - usepoll = True - @unittest.skipUnless(hasattr(asyncore, 'file_wrapper'), 'asyncore.file_wrapper required') class FileWrapperTest(unittest.TestCase): diff --git a/Lib/test/test_augassign.py b/Lib/test/test_augassign.py index 9a59c58..19b7687 100644 --- a/Lib/test/test_augassign.py +++ b/Lib/test/test_augassign.py @@ -136,6 +136,14 @@ class AugAssignTest(unittest.TestCase): output.append("__imul__ called") return self + def __matmul__(self, val): + output.append("__matmul__ called") + def __rmatmul__(self, val): + output.append("__rmatmul__ called") + def __imatmul__(self, val): + output.append("__imatmul__ called") + return self + def __div__(self, val): output.append("__div__ called") def __rdiv__(self, val): @@ -233,6 +241,10 @@ class AugAssignTest(unittest.TestCase): 1 * x x *= 1 + x @ 1 + 1 @ x + x @= 1 + x / 1 1 / x x /= 1 @@ -279,6 +291,9 @@ __isub__ called __mul__ called __rmul__ called __imul__ called +__matmul__ called +__rmatmul__ called +__imatmul__ called __truediv__ called __rtruediv__ called __itruediv__ called diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py index b561a6f..018ac8d 100644 --- a/Lib/test/test_builtin.py +++ b/Lib/test/test_builtin.py @@ -1092,7 +1092,7 @@ class BuiltinTest(unittest.TestCase): self.assertAlmostEqual(pow(-1, 0.5), 1j) self.assertAlmostEqual(pow(-1, 1/3), 0.5 + 0.8660254037844386j) - self.assertRaises(TypeError, pow, -1, -2, 3) + self.assertRaises(ValueError, pow, -1, -2, 3) self.assertRaises(ValueError, pow, 1, 2, 0) self.assertRaises(TypeError, pow) diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py index ba7c38d..ba7f2c4 100644 --- a/Lib/test/test_capi.py +++ b/Lib/test/test_capi.py @@ -150,6 +150,23 @@ class CAPITest(unittest.TestCase): self.assertEqual(_testcapi.docstring_with_signature_and_extra_newlines.__text_signature__, "($module, /, parameter)") + def test_c_type_with_matrix_multiplication(self): + M = _testcapi.matmulType + m1 = M() + m2 = M() + self.assertEqual(m1 @ m2, ("matmul", m1, m2)) + self.assertEqual(m1 @ 42, ("matmul", m1, 42)) + self.assertEqual(42 @ m1, ("matmul", 42, m1)) + o = m1 + o @= m2 + self.assertEqual(o, ("imatmul", m1, m2)) + o = m1 + o @= 42 + self.assertEqual(o, ("imatmul", m1, 42)) + o = 42 + o @= m1 + self.assertEqual(o, ("matmul", 42, m1)) + @unittest.skipUnless(threading, 'Threading required for this test.') class TestPendingCalls(unittest.TestCase): @@ -319,34 +336,38 @@ class EmbeddingTests(unittest.TestCase): print() print(out) print(err) + expected_errors = sys.__stdout__.errors expected_stdin_encoding = sys.__stdin__.encoding expected_pipe_encoding = self._get_default_pipe_encoding() expected_output = os.linesep.join([ "--- Use defaults ---", "Expected encoding: default", "Expected errors: default", - "stdin: {0}:strict", - "stdout: {1}:strict", - "stderr: {1}:backslashreplace", + "stdin: {in_encoding}:{errors}", + "stdout: {out_encoding}:{errors}", + "stderr: {out_encoding}:backslashreplace", "--- Set errors only ---", "Expected encoding: default", - "Expected errors: surrogateescape", - "stdin: {0}:surrogateescape", - "stdout: {1}:surrogateescape", - "stderr: {1}:backslashreplace", + "Expected errors: ignore", + "stdin: {in_encoding}:ignore", + "stdout: {out_encoding}:ignore", + "stderr: {out_encoding}:backslashreplace", "--- Set encoding only ---", "Expected encoding: latin-1", "Expected errors: default", - "stdin: latin-1:strict", - "stdout: latin-1:strict", + "stdin: latin-1:{errors}", + "stdout: latin-1:{errors}", "stderr: latin-1:backslashreplace", "--- Set encoding and errors ---", "Expected encoding: latin-1", - "Expected errors: surrogateescape", - "stdin: latin-1:surrogateescape", - "stdout: latin-1:surrogateescape", - "stderr: latin-1:backslashreplace"]).format(expected_stdin_encoding, - expected_pipe_encoding) + "Expected errors: replace", + "stdin: latin-1:replace", + "stdout: latin-1:replace", + "stderr: latin-1:backslashreplace"]) + expected_output = expected_output.format( + in_encoding=expected_stdin_encoding, + out_encoding=expected_pipe_encoding, + errors=expected_errors) # This is useful if we ever trip over odd platform behaviour self.maxDiff = None self.assertEqual(out.strip(), expected_output) diff --git a/Lib/test/test_codeccallbacks.py b/Lib/test/test_codeccallbacks.py index 84804bb..a1ce9cf 100644 --- a/Lib/test/test_codeccallbacks.py +++ b/Lib/test/test_codeccallbacks.py @@ -819,7 +819,7 @@ class CodecCallbackTest(unittest.TestCase): def __getitem__(self, key): raise ValueError #self.assertRaises(ValueError, "\xff".translate, D()) - self.assertRaises(TypeError, "\xff".translate, {0xff: sys.maxunicode+1}) + self.assertRaises(ValueError, "\xff".translate, {0xff: sys.maxunicode+1}) self.assertRaises(TypeError, "\xff".translate, {0xff: ()}) def test_bug828737(self): diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py index 9b62d5b..f59c37d 100644 --- a/Lib/test/test_codecs.py +++ b/Lib/test/test_codecs.py @@ -890,10 +890,6 @@ class CP65001Test(ReadTest, unittest.TestCase): "\U00010fff\uD800") self.assertTrue(codecs.lookup_error("surrogatepass")) - def test_readline(self): - self.skipTest("issue #20571: code page 65001 codec does not " - "support partial decoder yet") - class UTF7Test(ReadTest, unittest.TestCase): encoding = "utf-7" @@ -1600,6 +1596,12 @@ class CodecsModuleTest(unittest.TestCase): self.assertEqual(codecs.decode(b'abc'), 'abc') self.assertRaises(UnicodeDecodeError, codecs.decode, b'\xff', 'ascii') + # test keywords + self.assertEqual(codecs.decode(obj=b'\xe4\xf6\xfc', encoding='latin-1'), + '\xe4\xf6\xfc') + self.assertEqual(codecs.decode(b'[\xff]', 'ascii', errors='ignore'), + '[]') + def test_encode(self): self.assertEqual(codecs.encode('\xe4\xf6\xfc', 'latin-1'), b'\xe4\xf6\xfc') @@ -1608,6 +1610,12 @@ class CodecsModuleTest(unittest.TestCase): self.assertEqual(codecs.encode('abc'), b'abc') self.assertRaises(UnicodeEncodeError, codecs.encode, '\xffff', 'ascii') + # test keywords + self.assertEqual(codecs.encode(obj='\xe4\xf6\xfc', encoding='latin-1'), + b'\xe4\xf6\xfc') + self.assertEqual(codecs.encode('[\xff]', 'ascii', errors='ignore'), + b'[]') + def test_register(self): self.assertRaises(TypeError, codecs.register) self.assertRaises(TypeError, codecs.register, 42) @@ -2750,15 +2758,15 @@ class CodePageTest(unittest.TestCase): self.assertRaisesRegex(UnicodeEncodeError, 'cp932', codecs.code_page_encode, 932, '\xff') self.assertRaisesRegex(UnicodeDecodeError, 'cp932', - codecs.code_page_decode, 932, b'\x81\x00') + codecs.code_page_decode, 932, b'\x81\x00', 'strict', True) self.assertRaisesRegex(UnicodeDecodeError, 'CP_UTF8', - codecs.code_page_decode, self.CP_UTF8, b'\xff') + codecs.code_page_decode, self.CP_UTF8, b'\xff', 'strict', True) def check_decode(self, cp, tests): for raw, errors, expected in tests: if expected is not None: try: - decoded = codecs.code_page_decode(cp, raw, errors) + decoded = codecs.code_page_decode(cp, raw, errors, True) except UnicodeDecodeError as err: self.fail('Unable to decode %a from "cp%s" with ' 'errors=%r: %s' % (raw, cp, errors, err)) @@ -2770,7 +2778,7 @@ class CodePageTest(unittest.TestCase): self.assertLessEqual(decoded[1], len(raw)) else: self.assertRaises(UnicodeDecodeError, - codecs.code_page_decode, cp, raw, errors) + codecs.code_page_decode, cp, raw, errors, True) def check_encode(self, cp, tests): for text, errors, expected in tests: @@ -2799,6 +2807,9 @@ class CodePageTest(unittest.TestCase): ('[\u20ac]', 'replace', b'[?]'), ('[\xff]', 'backslashreplace', b'[\\xff]'), ('[\xff]', 'xmlcharrefreplace', b'[ÿ]'), + ('\udcff', 'strict', None), + ('[\udcff]', 'surrogateescape', b'[\xff]'), + ('[\udcff]', 'surrogatepass', None), )) self.check_decode(932, ( (b'abc', 'strict', 'abc'), @@ -2808,6 +2819,7 @@ class CodePageTest(unittest.TestCase): (b'[\xff]', 'ignore', '[]'), (b'[\xff]', 'replace', '[\ufffd]'), (b'[\xff]', 'surrogateescape', '[\udcff]'), + (b'[\xff]', 'surrogatepass', None), (b'\x81\x00abc', 'strict', None), (b'\x81\x00abc', 'ignore', '\x00abc'), (b'\x81\x00abc', 'replace', '\ufffd\x00abc'), @@ -2818,9 +2830,12 @@ class CodePageTest(unittest.TestCase): ('abc', 'strict', b'abc'), ('\xe9\u20ac', 'strict', b'\xe9\x80'), ('\xff', 'strict', b'\xff'), + # test error handlers ('\u0141', 'strict', None), ('\u0141', 'ignore', b''), ('\u0141', 'replace', b'L'), + ('\udc98', 'surrogateescape', b'\x98'), + ('\udc98', 'surrogatepass', None), )) self.check_decode(1252, ( (b'abc', 'strict', 'abc'), diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py index 6407b6f..e948106 100644 --- a/Lib/test/test_collections.py +++ b/Lib/test/test_collections.py @@ -640,6 +640,59 @@ class TestCollectionABCs(ABCTestCase): a, b = OneTwoThreeSet(), OneTwoThreeSet() self.assertTrue(hash(a) == hash(b)) + def test_isdisjoint_Set(self): + class MySet(Set): + def __init__(self, itr): + self.contents = itr + def __contains__(self, x): + return x in self.contents + def __iter__(self): + return iter(self.contents) + def __len__(self): + return len([x for x in self.contents]) + s1 = MySet((1, 2, 3)) + s2 = MySet((4, 5, 6)) + s3 = MySet((1, 5, 6)) + self.assertTrue(s1.isdisjoint(s2)) + self.assertFalse(s1.isdisjoint(s3)) + + def test_equality_Set(self): + class MySet(Set): + def __init__(self, itr): + self.contents = itr + def __contains__(self, x): + return x in self.contents + def __iter__(self): + return iter(self.contents) + def __len__(self): + return len([x for x in self.contents]) + s1 = MySet((1,)) + s2 = MySet((1, 2)) + s3 = MySet((3, 4)) + s4 = MySet((3, 4)) + self.assertTrue(s2 > s1) + self.assertTrue(s1 < s2) + self.assertFalse(s2 <= s1) + self.assertFalse(s2 <= s3) + self.assertFalse(s1 >= s2) + self.assertEqual(s3, s4) + self.assertNotEqual(s2, s3) + + def test_arithmetic_Set(self): + class MySet(Set): + def __init__(self, itr): + self.contents = itr + def __contains__(self, x): + return x in self.contents + def __iter__(self): + return iter(self.contents) + def __len__(self): + return len([x for x in self.contents]) + s1 = MySet((1, 2, 3)) + s2 = MySet((3, 4, 5)) + s3 = s1 & s2 + self.assertEqual(s3, MySet((3,))) + def test_MutableSet(self): self.assertIsInstance(set(), MutableSet) self.assertTrue(issubclass(set, MutableSet)) @@ -1339,6 +1392,21 @@ class TestOrderedDict(unittest.TestCase): self.assertEqual(list(od.items()), pairs) self.assertEqual(list(reversed(od)), [t[0] for t in reversed(pairs)]) + self.assertEqual(list(reversed(od.keys())), + [t[0] for t in reversed(pairs)]) + self.assertEqual(list(reversed(od.values())), + [t[1] for t in reversed(pairs)]) + self.assertEqual(list(reversed(od.items())), list(reversed(pairs))) + + def test_detect_deletion_during_iteration(self): + od = OrderedDict.fromkeys('abc') + it = iter(od) + key = next(it) + del od[key] + with self.assertRaises(Exception): + # Note, the exact exception raised is not guaranteed + # The only guarantee that the next() will not succeed + next(it) def test_popitem(self): pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)] diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py index c74b2ca..83184c3 100644 --- a/Lib/test/test_concurrent_futures.py +++ b/Lib/test/test_concurrent_futures.py @@ -425,6 +425,13 @@ class ExecutorTest: self.assertTrue(collected, "Stale reference not collected within timeout.") + def test_max_workers_negative(self): + for number in (0, -1): + with self.assertRaisesRegex(ValueError, + "max_workers must be greater " + "than 0"): + self.executor_type(max_workers=number) + class ThreadPoolExecutorTest(ThreadPoolMixin, ExecutorTest, unittest.TestCase): def test_map_submits_without_iteration(self): diff --git a/Lib/test/test_cprofile.py b/Lib/test/test_cprofile.py index ce5d27e..f18983f 100644 --- a/Lib/test/test_cprofile.py +++ b/Lib/test/test_cprofile.py @@ -11,7 +11,7 @@ from test.profilee import testfunc class CProfileTest(ProfileTest): profilerclass = cProfile.Profile profilermodule = cProfile - expected_max_output = "{built-in method max}" + expected_max_output = "{built-in method builtins.max}" def get_expected_output(self): return _ProfileOutput @@ -72,9 +72,9 @@ profilee.py:84(helper2_indirect) <- 2 0.000 0.140 profilee.py:88(helper2) <- 6 0.234 0.300 profilee.py:55(helper) 2 0.078 0.100 profilee.py:84(helper2_indirect) profilee.py:98(subhelper) <- 8 0.064 0.080 profilee.py:88(helper2) -{built-in method exc_info} <- 4 0.000 0.000 profilee.py:73(helper1) -{built-in method hasattr} <- 4 0.000 0.004 profilee.py:73(helper1) +{built-in method builtins.hasattr} <- 4 0.000 0.004 profilee.py:73(helper1) 8 0.000 0.008 profilee.py:88(helper2) +{built-in method sys.exc_info} <- 4 0.000 0.000 profilee.py:73(helper1) {method 'append' of 'list' objects} <- 4 0.000 0.000 profilee.py:73(helper1)""" _ProfileOutput['print_callees'] = """\ <string>:1(<module>) -> 1 0.270 1.000 profilee.py:25(testfunc) @@ -87,12 +87,12 @@ profilee.py:48(mul) -> profilee.py:55(helper) -> 4 0.116 0.120 profilee.py:73(helper1) 2 0.000 0.140 profilee.py:84(helper2_indirect) 6 0.234 0.300 profilee.py:88(helper2) -profilee.py:73(helper1) -> 4 0.000 0.000 {built-in method exc_info} +profilee.py:73(helper1) -> 4 0.000 0.004 {built-in method builtins.hasattr} profilee.py:84(helper2_indirect) -> 2 0.006 0.040 profilee.py:35(factorial) 2 0.078 0.100 profilee.py:88(helper2) profilee.py:88(helper2) -> 8 0.064 0.080 profilee.py:98(subhelper) profilee.py:98(subhelper) -> 16 0.016 0.016 profilee.py:110(__getattr__) -{built-in method hasattr} -> 12 0.012 0.012 profilee.py:110(__getattr__)""" +{built-in method builtins.hasattr} -> 12 0.012 0.012 profilee.py:110(__getattr__)""" if __name__ == "__main__": main() diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py index 7e2485f..7c31ac7 100644 --- a/Lib/test/test_csv.py +++ b/Lib/test/test_csv.py @@ -575,6 +575,16 @@ class TestDictFields(unittest.TestCase): fileobj.readline() # header self.assertEqual(fileobj.read(), "10,,abc\r\n") + def test_write_multiple_dict_rows(self): + fileobj = StringIO() + writer = csv.DictWriter(fileobj, fieldnames=["f1", "f2", "f3"]) + writer.writeheader() + self.assertEqual(fileobj.getvalue(), "f1,f2,f3\r\n") + writer.writerows([{"f1": 1, "f2": "abc", "f3": "f"}, + {"f1": 2, "f2": 5, "f3": "xyz"}]) + self.assertEqual(fileobj.getvalue(), + "f1,f2,f3\r\n1,abc,f\r\n2,5,xyz\r\n") + def test_write_no_fields(self): fileobj = StringIO() self.assertRaises(TypeError, csv.DictWriter, fileobj) diff --git a/Lib/test/test_dbm_dumb.py b/Lib/test/test_dbm_dumb.py index 29f48a3..ee5a32f 100644 --- a/Lib/test/test_dbm_dumb.py +++ b/Lib/test/test_dbm_dumb.py @@ -217,6 +217,14 @@ class DumbDBMTestCase(unittest.TestCase): self.assertEqual(str(cm.exception), "DBM object has already been closed") + def test_create_new(self): + with dumbdbm.open(_fname, 'n') as f: + for k in self._dict: + f[k] = self._dict[k] + + with dumbdbm.open(_fname, 'n') as f: + self.assertEqual(f.keys(), []) + def tearDown(self): _delete_files() diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py index 8358ba6..f8bb7eb 100644 --- a/Lib/test/test_decimal.py +++ b/Lib/test/test_decimal.py @@ -33,12 +33,13 @@ import unittest import numbers import locale from test.support import (run_unittest, run_doctest, is_resource_enabled, - requires_IEEE_754) + requires_IEEE_754, requires_docstrings) from test.support import (check_warnings, import_fresh_module, TestFailed, run_with_locale, cpython_only) import random import time import warnings +import inspect try: import threading except ImportError: @@ -4448,18 +4449,6 @@ class PyCoverage(Coverage): class PyFunctionality(unittest.TestCase): """Extra functionality in decimal.py""" - def test_py_quantize_watchexp(self): - # watchexp functionality - Decimal = P.Decimal - localcontext = P.localcontext - - with localcontext() as c: - c.prec = 1 - c.Emax = 1 - c.Emin = -1 - x = Decimal(99999).quantize(Decimal("1e3"), watchexp=False) - self.assertEqual(x, Decimal('1.00E+5')) - def test_py_alternate_formatting(self): # triples giving a format, a Decimal, and the expected result Decimal = P.Decimal @@ -5402,6 +5391,143 @@ class CWhitebox(unittest.TestCase): y = Decimal(10**(9*25)).__sizeof__() self.assertEqual(y, x+4) +@requires_docstrings +@unittest.skipUnless(C, "test requires C version") +class SignatureTest(unittest.TestCase): + """Function signatures""" + + def test_inspect_module(self): + for attr in dir(P): + if attr.startswith('_'): + continue + p_func = getattr(P, attr) + c_func = getattr(C, attr) + if (attr == 'Decimal' or attr == 'Context' or + inspect.isfunction(p_func)): + p_sig = inspect.signature(p_func) + c_sig = inspect.signature(c_func) + + # parameter names: + c_names = list(c_sig.parameters.keys()) + p_names = [x for x in p_sig.parameters.keys() if not + x.startswith('_')] + + self.assertEqual(c_names, p_names, + msg="parameter name mismatch in %s" % p_func) + + c_kind = [x.kind for x in c_sig.parameters.values()] + p_kind = [x[1].kind for x in p_sig.parameters.items() if not + x[0].startswith('_')] + + # parameters: + if attr != 'setcontext': + self.assertEqual(c_kind, p_kind, + msg="parameter kind mismatch in %s" % p_func) + + def test_inspect_types(self): + + POS = inspect._ParameterKind.POSITIONAL_ONLY + POS_KWD = inspect._ParameterKind.POSITIONAL_OR_KEYWORD + + # Type heuristic (type annotations would help!): + pdict = {C: {'other': C.Decimal(1), + 'third': C.Decimal(1), + 'x': C.Decimal(1), + 'y': C.Decimal(1), + 'z': C.Decimal(1), + 'a': C.Decimal(1), + 'b': C.Decimal(1), + 'c': C.Decimal(1), + 'exp': C.Decimal(1), + 'modulo': C.Decimal(1), + 'num': "1", + 'f': 1.0, + 'rounding': C.ROUND_HALF_UP, + 'context': C.getcontext()}, + P: {'other': P.Decimal(1), + 'third': P.Decimal(1), + 'a': P.Decimal(1), + 'b': P.Decimal(1), + 'c': P.Decimal(1), + 'exp': P.Decimal(1), + 'modulo': P.Decimal(1), + 'num': "1", + 'f': 1.0, + 'rounding': P.ROUND_HALF_UP, + 'context': P.getcontext()}} + + def mkargs(module, sig): + args = [] + kwargs = {} + for name, param in sig.parameters.items(): + if name == 'self': continue + if param.kind == POS: + args.append(pdict[module][name]) + elif param.kind == POS_KWD: + kwargs[name] = pdict[module][name] + else: + raise TestFailed("unexpected parameter kind") + return args, kwargs + + def tr(s): + """The C Context docstrings use 'x' in order to prevent confusion + with the article 'a' in the descriptions.""" + if s == 'x': return 'a' + if s == 'y': return 'b' + if s == 'z': return 'c' + return s + + def doit(ty): + p_type = getattr(P, ty) + c_type = getattr(C, ty) + for attr in dir(p_type): + if attr.startswith('_'): + continue + p_func = getattr(p_type, attr) + c_func = getattr(c_type, attr) + if inspect.isfunction(p_func): + p_sig = inspect.signature(p_func) + c_sig = inspect.signature(c_func) + + # parameter names: + p_names = list(p_sig.parameters.keys()) + c_names = [tr(x) for x in c_sig.parameters.keys()] + + self.assertEqual(c_names, p_names, + msg="parameter name mismatch in %s" % p_func) + + p_kind = [x.kind for x in p_sig.parameters.values()] + c_kind = [x.kind for x in c_sig.parameters.values()] + + # 'self' parameter: + self.assertIs(p_kind[0], POS_KWD) + self.assertIs(c_kind[0], POS) + + # remaining parameters: + if ty == 'Decimal': + self.assertEqual(c_kind[1:], p_kind[1:], + msg="parameter kind mismatch in %s" % p_func) + else: # Context methods are positional only in the C version. + self.assertEqual(len(c_kind), len(p_kind), + msg="parameter kind mismatch in %s" % p_func) + + # Run the function: + args, kwds = mkargs(C, c_sig) + try: + getattr(c_type(9), attr)(*args, **kwds) + except Exception as err: + raise TestFailed("invalid signature for %s: %s %s" % (c_func, args, kwds)) + + args, kwds = mkargs(P, p_sig) + try: + getattr(p_type(9), attr)(*args, **kwds) + except Exception as err: + raise TestFailed("invalid signature for %s: %s %s" % (p_func, args, kwds)) + + doit('Decimal') + doit('Context') + + all_tests = [ CExplicitConstructionTest, PyExplicitConstructionTest, CImplicitConstructionTest, PyImplicitConstructionTest, @@ -5427,6 +5553,7 @@ if not C: all_tests = all_tests[1::2] else: all_tests.insert(0, CheckAttributes) + all_tests.insert(1, SignatureTest) def test_main(arith=None, verbose=None, todo_tests=None, debug=None): diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py index 7bff1d2..787181c 100644 --- a/Lib/test/test_deque.py +++ b/Lib/test/test_deque.py @@ -507,6 +507,11 @@ class TestBasic(unittest.TestCase): for s in ('abcd', range(2000)): self.assertEqual(list(reversed(deque(s))), list(reversed(s))) + def test_reversed_new(self): + klass = type(reversed(deque())) + for s in ('abcd', range(2000)): + self.assertEqual(list(klass(deque(s))), list(reversed(s))) + def test_gc_doesnt_blowup(self): import gc # This used to assert-fail in deque_traverse() under a debug diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py index 26c273a..634ba7e 100644 --- a/Lib/test/test_descr.py +++ b/Lib/test/test_descr.py @@ -4160,6 +4160,7 @@ order (MRO) for bases """ ('__add__', 'x + y', 'x += y'), ('__sub__', 'x - y', 'x -= y'), ('__mul__', 'x * y', 'x *= y'), + ('__matmul__', 'x @ y', 'x @= y'), ('__truediv__', 'operator.truediv(x, y)', None), ('__floordiv__', 'operator.floordiv(x, y)', None), ('__div__', 'x / y', 'x /= y'), diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py index 56193e8..c62e7ca 100644 --- a/Lib/test/test_doctest.py +++ b/Lib/test/test_doctest.py @@ -2096,22 +2096,9 @@ def test_DocTestSuite(): >>> suite.run(unittest.TestResult()) <unittest.result.TestResult run=0 errors=0 failures=0> - However, if DocTestSuite finds no docstrings, it raises an error: + The module need not contain any docstrings either: - >>> try: - ... doctest.DocTestSuite('test.sample_doctest_no_docstrings') - ... except ValueError as e: - ... error = e - - >>> print(error.args[1]) - has no docstrings - - You can prevent this error by passing a DocTestFinder instance with - the `exclude_empty` keyword argument set to False: - - >>> finder = doctest.DocTestFinder(exclude_empty=False) - >>> suite = doctest.DocTestSuite('test.sample_doctest_no_docstrings', - ... test_finder=finder) + >>> suite = doctest.DocTestSuite('test.sample_doctest_no_docstrings') >>> suite.run(unittest.TestResult()) <unittest.result.TestResult run=0 errors=0 failures=0> @@ -2121,6 +2108,22 @@ def test_DocTestSuite(): >>> suite.run(unittest.TestResult()) <unittest.result.TestResult run=9 errors=0 failures=4> + We can also provide a DocTestFinder: + + >>> finder = doctest.DocTestFinder() + >>> suite = doctest.DocTestSuite('test.sample_doctest', + ... test_finder=finder) + >>> suite.run(unittest.TestResult()) + <unittest.result.TestResult run=9 errors=0 failures=4> + + The DocTestFinder need not return any tests: + + >>> finder = doctest.DocTestFinder() + >>> suite = doctest.DocTestSuite('test.sample_doctest_no_docstrings', + ... test_finder=finder) + >>> suite.run(unittest.TestResult()) + <unittest.result.TestResult run=0 errors=0 failures=0> + We can supply global variables. If we pass globs, they will be used instead of the module globals. Here we'll pass an empty globals, triggering an extra error: @@ -2168,7 +2171,7 @@ def test_DocTestSuite(): >>> test.test_doctest.sillySetup Traceback (most recent call last): ... - AttributeError: 'module' object has no attribute 'sillySetup' + AttributeError: module 'test.test_doctest' has no attribute 'sillySetup' The setUp and tearDown funtions are passed test objects. Here we'll use the setUp function to supply the missing variable y: @@ -2314,7 +2317,7 @@ def test_DocFileSuite(): >>> test.test_doctest.sillySetup Traceback (most recent call last): ... - AttributeError: 'module' object has no attribute 'sillySetup' + AttributeError: module 'test.test_doctest' has no attribute 'sillySetup' The setUp and tearDown funtions are passed test objects. Here, we'll use a setUp function to set the favorite color in @@ -2897,7 +2900,7 @@ Invalid doctest option: def test_main(): # Check the doctest cases in doctest itself: - support.run_doctest(doctest, verbosity=True) + ret = support.run_doctest(doctest, verbosity=True) # Check the doctest cases defined here: from test import test_doctest support.run_doctest(test_doctest, verbosity=True) diff --git a/Lib/test/test_docxmlrpc.py b/Lib/test/test_docxmlrpc.py index cb6366c..eb97516 100644 --- a/Lib/test/test_docxmlrpc.py +++ b/Lib/test/test_docxmlrpc.py @@ -87,10 +87,11 @@ class DocXMLRPCHTTPGETServer(unittest.TestCase): threading.Thread(target=server, args=(self.evt, 1)).start() # wait for port to be assigned - n = 1000 - while n > 0 and PORT is None: - time.sleep(0.001) - n -= 1 + deadline = time.monotonic() + 10.0 + while PORT is None: + time.sleep(0.010) + if time.monotonic() > deadline: + break self.client = http.client.HTTPConnection("localhost:%d" % PORT) diff --git a/Lib/test/test_fileio.py b/Lib/test/test_fileio.py index c37482e..b87dc07 100644 --- a/Lib/test/test_fileio.py +++ b/Lib/test/test_fileio.py @@ -60,6 +60,15 @@ class AutoFileTests(unittest.TestCase): self.assertRaises((AttributeError, TypeError), setattr, f, attr, 'oops') + def testBlksize(self): + # test private _blksize attribute + blksize = io.DEFAULT_BUFFER_SIZE + # try to get preferred blksize from stat.st_blksize, if available + if hasattr(os, 'fstat'): + fst = os.fstat(self.f.fileno()) + blksize = getattr(fst, 'st_blksize', blksize) + self.assertEqual(self.f._blksize, blksize) + def testReadinto(self): # verify readinto self.f.write(bytes([1, 2])) @@ -141,7 +150,7 @@ class AutoFileTests(unittest.TestCase): def testOpendir(self): # Issue 3703: opening a directory should fill the errno # Windows always returns "[Errno 13]: Permission denied - # Unix calls dircheck() and returns "[Errno 21]: Is a directory" + # Unix uses fstat and returns "[Errno 21]: Is a directory" try: _FileIO('.', 'r') except OSError as e: diff --git a/Lib/test/test_fork1.py b/Lib/test/test_fork1.py index e0626df..8bcbd46 100644 --- a/Lib/test/test_fork1.py +++ b/Lib/test/test_fork1.py @@ -18,13 +18,14 @@ get_attribute(os, 'fork') class ForkTest(ForkWait): def wait_impl(self, cpid): - for i in range(10): + deadline = time.monotonic() + 10.0 + while time.monotonic() <= deadline: # waitpid() shouldn't hang, but some of the buildbots seem to hang # in the forking tests. This is an attempt to fix the problem. spid, status = os.waitpid(cpid, os.WNOHANG) if spid == cpid: break - time.sleep(1.0) + time.sleep(0.1) self.assertEqual(spid, cpid) self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8)) diff --git a/Lib/test/test_format.py b/Lib/test/test_format.py index fc71e48..631bf35 100644 --- a/Lib/test/test_format.py +++ b/Lib/test/test_format.py @@ -142,8 +142,6 @@ class FormatTest(unittest.TestCase): testformat("%#+027.23X", big, "+0X0001234567890ABCDEF12345") # same, except no 0 flag testformat("%#+27.23X", big, " +0X001234567890ABCDEF12345") - with self.assertWarns(DeprecationWarning): - testformat("%x", float(big), "123456_______________", 6) big = 0o12345670123456701234567012345670 # 32 octal digits testformat("%o", big, "12345670123456701234567012345670") testformat("%o", -big, "-12345670123456701234567012345670") @@ -183,8 +181,6 @@ class FormatTest(unittest.TestCase): testformat("%034.33o", big, "0012345670123456701234567012345670") # base marker shouldn't change that testformat("%0#34.33o", big, "0o012345670123456701234567012345670") - with self.assertWarns(DeprecationWarning): - testformat("%o", float(big), "123456__________________________", 6) # Some small ints, in both Python int and flavors). testformat("%d", 42, "42") testformat("%d", -42, "-42") @@ -195,8 +191,6 @@ class FormatTest(unittest.TestCase): testformat("%#x", 1, "0x1") testformat("%#X", 1, "0X1") testformat("%#X", 1, "0X1") - with self.assertWarns(DeprecationWarning): - testformat("%#x", 1.0, "0x1") testformat("%#o", 1, "0o1") testformat("%#o", 1, "0o1") testformat("%#o", 0, "0o0") @@ -213,14 +207,10 @@ class FormatTest(unittest.TestCase): testformat("%x", -0x42, "-42") testformat("%x", 0x42, "42") testformat("%x", -0x42, "-42") - with self.assertWarns(DeprecationWarning): - testformat("%x", float(0x42), "42") testformat("%o", 0o42, "42") testformat("%o", -0o42, "-42") testformat("%o", 0o42, "42") testformat("%o", -0o42, "-42") - with self.assertWarns(DeprecationWarning): - testformat("%o", float(0o42), "42") testformat("%r", "\u0378", "'\\u0378'") # non printable testformat("%a", "\u0378", "'\\u0378'") # non printable testformat("%r", "\u0374", "'\u0374'") # printable diff --git a/Lib/test/test_fractions.py b/Lib/test/test_fractions.py index 3336532..e86d5ce 100644 --- a/Lib/test/test_fractions.py +++ b/Lib/test/test_fractions.py @@ -330,7 +330,6 @@ class FractionTest(unittest.TestCase): self.assertTypedEquals(F(-2, 10), round(F(-15, 100), 1)) self.assertTypedEquals(F(-2, 10), round(F(-25, 100), 1)) - def testArithmetic(self): self.assertEqual(F(1, 2), F(1, 10) + F(2, 5)) self.assertEqual(F(-3, 10), F(1, 10) - F(2, 5)) @@ -402,6 +401,8 @@ class FractionTest(unittest.TestCase): self.assertTypedEquals(2.0 , 4 ** F(1, 2)) self.assertTypedEquals(0.25, 2.0 ** F(-2, 1)) self.assertTypedEquals(1.0 + 0j, (1.0 + 0j) ** F(1, 10)) + self.assertRaises(ZeroDivisionError, operator.pow, + F(0, 1), -2) def testMixingWithDecimal(self): # Decimal refuses mixed arithmetic (but not mixed comparisons) diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py index 91afe47..3882f4c 100644 --- a/Lib/test/test_generators.py +++ b/Lib/test/test_generators.py @@ -50,6 +50,45 @@ class FinalizationTest(unittest.TestCase): self.assertEqual(gc.garbage, old_garbage) +class GeneratorTest(unittest.TestCase): + + def test_name(self): + def func(): + yield 1 + + # check generator names + gen = func() + self.assertEqual(gen.__name__, "func") + self.assertEqual(gen.__qualname__, + "GeneratorTest.test_name.<locals>.func") + + # modify generator names + gen.__name__ = "name" + gen.__qualname__ = "qualname" + self.assertEqual(gen.__name__, "name") + self.assertEqual(gen.__qualname__, "qualname") + + # generator names must be a string and cannot be deleted + self.assertRaises(TypeError, setattr, gen, '__name__', 123) + self.assertRaises(TypeError, setattr, gen, '__qualname__', 123) + self.assertRaises(TypeError, delattr, gen, '__name__') + self.assertRaises(TypeError, delattr, gen, '__qualname__') + + # modify names of the function creating the generator + func.__qualname__ = "func_qualname" + func.__name__ = "func_name" + gen = func() + self.assertEqual(gen.__name__, "func_name") + self.assertEqual(gen.__qualname__, "func_qualname") + + # unnamed generator + gen = (x for x in range(10)) + self.assertEqual(gen.__name__, + "<genexpr>") + self.assertEqual(gen.__qualname__, + "GeneratorTest.test_name.<locals>.<genexpr>") + + tutorial_tests = """ Let's try a simple generator: diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py index 70d85b1..7069fb9 100644 --- a/Lib/test/test_grammar.py +++ b/Lib/test/test_grammar.py @@ -1016,6 +1016,20 @@ class GrammarTests(unittest.TestCase): self.assertFalse((False is 2) is 3) self.assertFalse(False is 2 is 3) + def test_matrix_mul(self): + # This is not intended to be a comprehensive test, rather just to be few + # samples of the @ operator in test_grammar.py. + class M: + def __matmul__(self, o): + return 4 + def __imatmul__(self, o): + self.other = o + return self + m = M() + self.assertEqual(m @ m, 4) + m @= 42 + self.assertEqual(m.other, 42) + def test_main(): run_unittest(TokenTests, GrammarTests) diff --git a/Lib/test/test_heapq.py b/Lib/test/test_heapq.py index b5a2fd8..0dcd8c5 100644 --- a/Lib/test/test_heapq.py +++ b/Lib/test/test_heapq.py @@ -6,14 +6,15 @@ import unittest from test import support from unittest import TestCase, skipUnless +from operator import itemgetter py_heapq = support.import_fresh_module('heapq', blocked=['_heapq']) c_heapq = support.import_fresh_module('heapq', fresh=['_heapq']) # _heapq.nlargest/nsmallest are saved in heapq._nlargest/_smallest when # _heapq is imported, so check them there -func_names = ['heapify', 'heappop', 'heappush', 'heappushpop', - 'heapreplace', '_nlargest', '_nsmallest'] +func_names = ['heapify', 'heappop', 'heappush', 'heappushpop', 'heapreplace', + '_heappop_max', '_heapreplace_max', '_heapify_max'] class TestModules(TestCase): def test_py_functions(self): @@ -152,11 +153,21 @@ class TestHeap: def test_merge(self): inputs = [] - for i in range(random.randrange(5)): - row = sorted(random.randrange(1000) for j in range(random.randrange(10))) + for i in range(random.randrange(25)): + row = [] + for j in range(random.randrange(100)): + tup = random.choice('ABC'), random.randrange(-500, 500) + row.append(tup) inputs.append(row) - self.assertEqual(sorted(chain(*inputs)), list(self.module.merge(*inputs))) - self.assertEqual(list(self.module.merge()), []) + + for key in [None, itemgetter(0), itemgetter(1), itemgetter(1, 0)]: + for reverse in [False, True]: + seqs = [] + for seq in inputs: + seqs.append(sorted(seq, key=key, reverse=reverse)) + self.assertEqual(sorted(chain(*inputs), key=key, reverse=reverse), + list(self.module.merge(*seqs, key=key, reverse=reverse))) + self.assertEqual(list(self.module.merge()), []) def test_merge_does_not_suppress_index_error(self): # Issue 19018: Heapq.merge suppresses IndexError from user generator diff --git a/Lib/test/test_httplib.py b/Lib/test/test_httplib.py index 22f7329..1a6d8d0 100644 --- a/Lib/test/test_httplib.py +++ b/Lib/test/test_httplib.py @@ -18,6 +18,26 @@ CERT_fakehostname = os.path.join(here, 'keycert2.pem') # Root cert file (CA) for svn.python.org's cert CACERT_svn_python_org = os.path.join(here, 'https_svn_python_org_root.pem') +# constants for testing chunked encoding +chunked_start = ( + 'HTTP/1.1 200 OK\r\n' + 'Transfer-Encoding: chunked\r\n\r\n' + 'a\r\n' + 'hello worl\r\n' + '3\r\n' + 'd! \r\n' + '8\r\n' + 'and now \r\n' + '22\r\n' + 'for something completely different\r\n' +) +chunked_expected = b'hello world! and now for something completely different' +chunk_extension = ";foo=bar" +last_chunk = "0\r\n" +last_chunk_extended = "0" + chunk_extension + "\r\n" +trailers = "X-Dummy: foo\r\nX-Dumm2: bar\r\n" +chunked_end = "\r\n" + HOST = support.HOST class FakeSocket: @@ -38,7 +58,10 @@ class FakeSocket: def makefile(self, mode, bufsize=None): if mode != 'r' and mode != 'rb': raise client.UnimplementedFileMode() - return self.fileclass(self.text) + # keep the file around so we can check how much was read from it + self.file = self.fileclass(self.text) + self.file.close = lambda:None #nerf close () + return self.file def close(self): pass @@ -435,20 +458,8 @@ class BasicTest(TestCase): conn.request('POST', 'test', conn) def test_chunked(self): - chunked_start = ( - 'HTTP/1.1 200 OK\r\n' - 'Transfer-Encoding: chunked\r\n\r\n' - 'a\r\n' - 'hello worl\r\n' - '3\r\n' - 'd! \r\n' - '8\r\n' - 'and now \r\n' - '22\r\n' - 'for something completely different\r\n' - ) - expected = b'hello world! and now for something completely different' - sock = FakeSocket(chunked_start + '0\r\n') + expected = chunked_expected + sock = FakeSocket(chunked_start + last_chunk + chunked_end) resp = client.HTTPResponse(sock, method="GET") resp.begin() self.assertEqual(resp.read(), expected) @@ -456,7 +467,7 @@ class BasicTest(TestCase): # Various read sizes for n in range(1, 12): - sock = FakeSocket(chunked_start + '0\r\n') + sock = FakeSocket(chunked_start + last_chunk + chunked_end) resp = client.HTTPResponse(sock, method="GET") resp.begin() self.assertEqual(resp.read(n) + resp.read(n) + resp.read(), expected) @@ -479,23 +490,12 @@ class BasicTest(TestCase): resp.close() def test_readinto_chunked(self): - chunked_start = ( - 'HTTP/1.1 200 OK\r\n' - 'Transfer-Encoding: chunked\r\n\r\n' - 'a\r\n' - 'hello worl\r\n' - '3\r\n' - 'd! \r\n' - '8\r\n' - 'and now \r\n' - '22\r\n' - 'for something completely different\r\n' - ) - expected = b'hello world! and now for something completely different' + + expected = chunked_expected nexpected = len(expected) b = bytearray(128) - sock = FakeSocket(chunked_start + '0\r\n') + sock = FakeSocket(chunked_start + last_chunk + chunked_end) resp = client.HTTPResponse(sock, method="GET") resp.begin() n = resp.readinto(b) @@ -505,7 +505,7 @@ class BasicTest(TestCase): # Various read sizes for n in range(1, 12): - sock = FakeSocket(chunked_start + '0\r\n') + sock = FakeSocket(chunked_start + last_chunk + chunked_end) resp = client.HTTPResponse(sock, method="GET") resp.begin() m = memoryview(b) @@ -541,7 +541,7 @@ class BasicTest(TestCase): '1\r\n' 'd\r\n' ) - sock = FakeSocket(chunked_start + '0\r\n') + sock = FakeSocket(chunked_start + last_chunk + chunked_end) resp = client.HTTPResponse(sock, method="HEAD") resp.begin() self.assertEqual(resp.read(), b'') @@ -561,7 +561,7 @@ class BasicTest(TestCase): '1\r\n' 'd\r\n' ) - sock = FakeSocket(chunked_start + '0\r\n') + sock = FakeSocket(chunked_start + last_chunk + chunked_end) resp = client.HTTPResponse(sock, method="HEAD") resp.begin() b = bytearray(5) @@ -636,6 +636,7 @@ class BasicTest(TestCase): + '0' * 65536 + 'a\r\n' 'hello world\r\n' '0\r\n' + '\r\n' ) resp = client.HTTPResponse(FakeSocket(body)) resp.begin() @@ -675,6 +676,239 @@ class BasicTest(TestCase): conn.request('POST', '/', body) self.assertGreater(sock.sendall_calls, 1) + def test_chunked_extension(self): + extra = '3;foo=bar\r\n' + 'abc\r\n' + expected = chunked_expected + b'abc' + + sock = FakeSocket(chunked_start + extra + last_chunk_extended + chunked_end) + resp = client.HTTPResponse(sock, method="GET") + resp.begin() + self.assertEqual(resp.read(), expected) + resp.close() + + def test_chunked_missing_end(self): + """some servers may serve up a short chunked encoding stream""" + expected = chunked_expected + sock = FakeSocket(chunked_start + last_chunk) #no terminating crlf + resp = client.HTTPResponse(sock, method="GET") + resp.begin() + self.assertEqual(resp.read(), expected) + resp.close() + + def test_chunked_trailers(self): + """See that trailers are read and ignored""" + expected = chunked_expected + sock = FakeSocket(chunked_start + last_chunk + trailers + chunked_end) + resp = client.HTTPResponse(sock, method="GET") + resp.begin() + self.assertEqual(resp.read(), expected) + # we should have reached the end of the file + self.assertEqual(sock.file.read(100), b"") #we read to the end + resp.close() + + def test_chunked_sync(self): + """Check that we don't read past the end of the chunked-encoding stream""" + expected = chunked_expected + extradata = "extradata" + sock = FakeSocket(chunked_start + last_chunk + trailers + chunked_end + extradata) + resp = client.HTTPResponse(sock, method="GET") + resp.begin() + self.assertEqual(resp.read(), expected) + # the file should now have our extradata ready to be read + self.assertEqual(sock.file.read(100), extradata.encode("ascii")) #we read to the end + resp.close() + + def test_content_length_sync(self): + """Check that we don't read past the end of the Content-Length stream""" + extradata = "extradata" + expected = b"Hello123\r\n" + sock = FakeSocket('HTTP/1.1 200 OK\r\nContent-Length: 10\r\n\r\nHello123\r\n' + extradata) + resp = client.HTTPResponse(sock, method="GET") + resp.begin() + self.assertEqual(resp.read(), expected) + # the file should now have our extradata ready to be read + self.assertEqual(sock.file.read(100), extradata.encode("ascii")) #we read to the end + resp.close() + +class ExtendedReadTest(TestCase): + """ + Test peek(), read1(), readline() + """ + lines = ( + 'HTTP/1.1 200 OK\r\n' + '\r\n' + 'hello world!\n' + 'and now \n' + 'for something completely different\n' + 'foo' + ) + lines_expected = lines[lines.find('hello'):].encode("ascii") + lines_chunked = ( + 'HTTP/1.1 200 OK\r\n' + 'Transfer-Encoding: chunked\r\n\r\n' + 'a\r\n' + 'hello worl\r\n' + '3\r\n' + 'd!\n\r\n' + '9\r\n' + 'and now \n\r\n' + '23\r\n' + 'for something completely different\n\r\n' + '3\r\n' + 'foo\r\n' + '0\r\n' # terminating chunk + '\r\n' # end of trailers + ) + + def setUp(self): + sock = FakeSocket(self.lines) + resp = client.HTTPResponse(sock, method="GET") + resp.begin() + resp.fp = io.BufferedReader(resp.fp) + self.resp = resp + + + + def test_peek(self): + resp = self.resp + # patch up the buffered peek so that it returns not too much stuff + oldpeek = resp.fp.peek + def mypeek(n=-1): + p = oldpeek(n) + if n >= 0: + return p[:n] + return p[:10] + resp.fp.peek = mypeek + + all = [] + while True: + # try a short peek + p = resp.peek(3) + if p: + self.assertGreater(len(p), 0) + # then unbounded peek + p2 = resp.peek() + self.assertGreaterEqual(len(p2), len(p)) + self.assertTrue(p2.startswith(p)) + next = resp.read(len(p2)) + self.assertEqual(next, p2) + else: + next = resp.read() + self.assertFalse(next) + all.append(next) + if not next: + break + self.assertEqual(b"".join(all), self.lines_expected) + + def test_readline(self): + resp = self.resp + self._verify_readline(self.resp.readline, self.lines_expected) + + def _verify_readline(self, readline, expected): + all = [] + while True: + # short readlines + line = readline(5) + if line and line != b"foo": + if len(line) < 5: + self.assertTrue(line.endswith(b"\n")) + all.append(line) + if not line: + break + self.assertEqual(b"".join(all), expected) + + def test_read1(self): + resp = self.resp + def r(): + res = resp.read1(4) + self.assertLessEqual(len(res), 4) + return res + readliner = Readliner(r) + self._verify_readline(readliner.readline, self.lines_expected) + + def test_read1_unbounded(self): + resp = self.resp + all = [] + while True: + data = resp.read1() + if not data: + break + all.append(data) + self.assertEqual(b"".join(all), self.lines_expected) + + def test_read1_bounded(self): + resp = self.resp + all = [] + while True: + data = resp.read1(10) + if not data: + break + self.assertLessEqual(len(data), 10) + all.append(data) + self.assertEqual(b"".join(all), self.lines_expected) + + def test_read1_0(self): + self.assertEqual(self.resp.read1(0), b"") + + def test_peek_0(self): + p = self.resp.peek(0) + self.assertLessEqual(0, len(p)) + +class ExtendedReadTestChunked(ExtendedReadTest): + """ + Test peek(), read1(), readline() in chunked mode + """ + lines = ( + 'HTTP/1.1 200 OK\r\n' + 'Transfer-Encoding: chunked\r\n\r\n' + 'a\r\n' + 'hello worl\r\n' + '3\r\n' + 'd!\n\r\n' + '9\r\n' + 'and now \n\r\n' + '23\r\n' + 'for something completely different\n\r\n' + '3\r\n' + 'foo\r\n' + '0\r\n' # terminating chunk + '\r\n' # end of trailers + ) + + +class Readliner: + """ + a simple readline class that uses an arbitrary read function and buffering + """ + def __init__(self, readfunc): + self.readfunc = readfunc + self.remainder = b"" + + def readline(self, limit): + data = [] + datalen = 0 + read = self.remainder + try: + while True: + idx = read.find(b'\n') + if idx != -1: + break + if datalen + len(read) >= limit: + idx = limit - datalen - 1 + # read more data + data.append(read) + read = self.readfunc() + if not read: + idx = 0 #eof condition + break + idx += 1 + data.append(read[:idx]) + self.remainder = read[idx:] + return b"".join(data) + except: + self.remainder = b"".join(data) + raise + class OfflineTest(TestCase): def test_responses(self): self.assertEqual(client.responses[client.NOT_FOUND], "Not Found") @@ -1019,7 +1253,8 @@ class TunnelTests(TestCase): def test_main(verbose=None): support.run_unittest(HeaderTests, OfflineTest, BasicTest, TimeoutTest, HTTPSTest, RequestBodyTest, SourceAddressTest, - HTTPResponseTest, TunnelTests) + HTTPResponseTest, ExtendedReadTest, + ExtendedReadTestChunked, TunnelTests) if __name__ == '__main__': test_main() diff --git a/Lib/test/test_imghdr.py b/Lib/test/test_imghdr.py index 0ad4343..b54daf8 100644 --- a/Lib/test/test_imghdr.py +++ b/Lib/test/test_imghdr.py @@ -16,7 +16,9 @@ TEST_FILES = ( ('python.ras', 'rast'), ('python.sgi', 'rgb'), ('python.tiff', 'tiff'), - ('python.xbm', 'xbm') + ('python.xbm', 'xbm'), + ('python.webp', 'webp'), + ('python.exr', 'exr'), ) class UnseekableIO(io.FileIO): diff --git a/Lib/test/test_importlib/builtin/test_finder.py b/Lib/test/test_importlib/builtin/test_finder.py index 934562f..a2e6e1e 100644 --- a/Lib/test/test_importlib/builtin/test_finder.py +++ b/Lib/test/test_importlib/builtin/test_finder.py @@ -1,21 +1,21 @@ from .. import abc from .. import util -from . import util as builtin_util -frozen_machinery, source_machinery = util.import_importlib('importlib.machinery') +machinery = util.import_importlib('importlib.machinery') import sys import unittest +@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module') class FindSpecTests(abc.FinderTests): """Test find_spec() for built-in modules.""" def test_module(self): # Common case. - with util.uncache(builtin_util.NAME): - found = self.machinery.BuiltinImporter.find_spec(builtin_util.NAME) + with util.uncache(util.BUILTINS.good_name): + found = self.machinery.BuiltinImporter.find_spec(util.BUILTINS.good_name) self.assertTrue(found) self.assertEqual(found.origin, 'built-in') @@ -39,23 +39,26 @@ class FindSpecTests(abc.FinderTests): def test_ignore_path(self): # The value for 'path' should always trigger a failed import. - with util.uncache(builtin_util.NAME): - spec = self.machinery.BuiltinImporter.find_spec(builtin_util.NAME, + with util.uncache(util.BUILTINS.good_name): + spec = self.machinery.BuiltinImporter.find_spec(util.BUILTINS.good_name, ['pkg']) self.assertIsNone(spec) -Frozen_FindSpecTests, Source_FindSpecTests = util.test_both(FindSpecTests, - machinery=[frozen_machinery, source_machinery]) +(Frozen_FindSpecTests, + Source_FindSpecTests + ) = util.test_both(FindSpecTests, machinery=machinery) + +@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module') class FinderTests(abc.FinderTests): """Test find_module() for built-in modules.""" def test_module(self): # Common case. - with util.uncache(builtin_util.NAME): - found = self.machinery.BuiltinImporter.find_module(builtin_util.NAME) + with util.uncache(util.BUILTINS.good_name): + found = self.machinery.BuiltinImporter.find_module(util.BUILTINS.good_name) self.assertTrue(found) self.assertTrue(hasattr(found, 'load_module')) @@ -72,13 +75,15 @@ class FinderTests(abc.FinderTests): def test_ignore_path(self): # The value for 'path' should always trigger a failed import. - with util.uncache(builtin_util.NAME): - loader = self.machinery.BuiltinImporter.find_module(builtin_util.NAME, + with util.uncache(util.BUILTINS.good_name): + loader = self.machinery.BuiltinImporter.find_module(util.BUILTINS.good_name, ['pkg']) self.assertIsNone(loader) -Frozen_FinderTests, Source_FinderTests = util.test_both(FinderTests, - machinery=[frozen_machinery, source_machinery]) + +(Frozen_FinderTests, + Source_FinderTests + ) = util.test_both(FinderTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/builtin/test_loader.py b/Lib/test/test_importlib/builtin/test_loader.py index 1f83574..1684ab6 100644 --- a/Lib/test/test_importlib/builtin/test_loader.py +++ b/Lib/test/test_importlib/builtin/test_loader.py @@ -1,14 +1,13 @@ from .. import abc from .. import util -from . import util as builtin_util -frozen_machinery, source_machinery = util.import_importlib('importlib.machinery') +machinery = util.import_importlib('importlib.machinery') import sys import types import unittest - +@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module') class LoaderTests(abc.LoaderTests): """Test load_module() for built-in modules.""" @@ -29,8 +28,8 @@ class LoaderTests(abc.LoaderTests): def test_module(self): # Common case. - with util.uncache(builtin_util.NAME): - module = self.load_module(builtin_util.NAME) + with util.uncache(util.BUILTINS.good_name): + module = self.load_module(util.BUILTINS.good_name) self.verify(module) # Built-in modules cannot be a package. @@ -41,9 +40,9 @@ class LoaderTests(abc.LoaderTests): def test_module_reuse(self): # Test that the same module is used in a reload. - with util.uncache(builtin_util.NAME): - module1 = self.load_module(builtin_util.NAME) - module2 = self.load_module(builtin_util.NAME) + with util.uncache(util.BUILTINS.good_name): + module1 = self.load_module(util.BUILTINS.good_name) + module2 = self.load_module(util.BUILTINS.good_name) self.assertIs(module1, module2) def test_unloadable(self): @@ -66,40 +65,44 @@ class LoaderTests(abc.LoaderTests): self.assertEqual(cm.exception.name, module_name) -Frozen_LoaderTests, Source_LoaderTests = util.test_both(LoaderTests, - machinery=[frozen_machinery, source_machinery]) +(Frozen_LoaderTests, + Source_LoaderTests + ) = util.test_both(LoaderTests, machinery=machinery) +@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module') class InspectLoaderTests: """Tests for InspectLoader methods for BuiltinImporter.""" def test_get_code(self): # There is no code object. - result = self.machinery.BuiltinImporter.get_code(builtin_util.NAME) + result = self.machinery.BuiltinImporter.get_code(util.BUILTINS.good_name) self.assertIsNone(result) def test_get_source(self): # There is no source. - result = self.machinery.BuiltinImporter.get_source(builtin_util.NAME) + result = self.machinery.BuiltinImporter.get_source(util.BUILTINS.good_name) self.assertIsNone(result) def test_is_package(self): # Cannot be a package. - result = self.machinery.BuiltinImporter.is_package(builtin_util.NAME) + result = self.machinery.BuiltinImporter.is_package(util.BUILTINS.good_name) self.assertFalse(result) + @unittest.skipIf(util.BUILTINS.bad_name is None, 'all modules are built in') def test_not_builtin(self): # Modules not built-in should raise ImportError. for meth_name in ('get_code', 'get_source', 'is_package'): method = getattr(self.machinery.BuiltinImporter, meth_name) with self.assertRaises(ImportError) as cm: - method(builtin_util.BAD_NAME) - self.assertRaises(builtin_util.BAD_NAME) + method(util.BUILTINS.bad_name) + self.assertRaises(util.BUILTINS.bad_name) + -Frozen_InspectLoaderTests, Source_InspectLoaderTests = util.test_both( - InspectLoaderTests, - machinery=[frozen_machinery, source_machinery]) +(Frozen_InspectLoaderTests, + Source_InspectLoaderTests + ) = util.test_both(InspectLoaderTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/builtin/util.py b/Lib/test/test_importlib/builtin/util.py deleted file mode 100644 index 5704699..0000000 --- a/Lib/test/test_importlib/builtin/util.py +++ /dev/null @@ -1,7 +0,0 @@ -import sys - -assert 'errno' in sys.builtin_module_names -NAME = 'errno' - -assert 'importlib' not in sys.builtin_module_names -BAD_NAME = 'importlib' diff --git a/Lib/test/test_importlib/extension/test_case_sensitivity.py b/Lib/test/test_importlib/extension/test_case_sensitivity.py index bb2528e..c7d6ca6 100644 --- a/Lib/test/test_importlib/extension/test_case_sensitivity.py +++ b/Lib/test/test_importlib/extension/test_case_sensitivity.py @@ -4,22 +4,21 @@ from test import support import unittest from .. import util -from . import util as ext_util -frozen_machinery, source_machinery = util.import_importlib('importlib.machinery') +machinery = util.import_importlib('importlib.machinery') # XXX find_spec tests -@unittest.skipIf(ext_util.FILENAME is None, '_testcapi not available') +@unittest.skipIf(util.EXTENSIONS.filename is None, '_testcapi not available') @util.case_insensitive_tests class ExtensionModuleCaseSensitivityTest: def find_module(self): - good_name = ext_util.NAME + good_name = util.EXTENSIONS.name bad_name = good_name.upper() assert good_name != bad_name - finder = self.machinery.FileFinder(ext_util.PATH, + finder = self.machinery.FileFinder(util.EXTENSIONS.path, (self.machinery.ExtensionFileLoader, self.machinery.EXTENSION_SUFFIXES)) return finder.find_module(bad_name) @@ -42,9 +41,10 @@ class ExtensionModuleCaseSensitivityTest: loader = self.find_module() self.assertTrue(hasattr(loader, 'load_module')) -Frozen_ExtensionCaseSensitivity, Source_ExtensionCaseSensitivity = util.test_both( - ExtensionModuleCaseSensitivityTest, - machinery=[frozen_machinery, source_machinery]) + +(Frozen_ExtensionCaseSensitivity, + Source_ExtensionCaseSensitivity + ) = util.test_both(ExtensionModuleCaseSensitivityTest, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/extension/test_finder.py b/Lib/test/test_importlib/extension/test_finder.py index 990f29c..71bf67f 100644 --- a/Lib/test/test_importlib/extension/test_finder.py +++ b/Lib/test/test_importlib/extension/test_finder.py @@ -1,8 +1,7 @@ from .. import abc -from .. import util as test_util -from . import util +from .. import util -machinery = test_util.import_importlib('importlib.machinery') +machinery = util.import_importlib('importlib.machinery') import unittest import warnings @@ -14,7 +13,7 @@ class FinderTests(abc.FinderTests): """Test the finder for extension modules.""" def find_module(self, fullname): - importer = self.machinery.FileFinder(util.PATH, + importer = self.machinery.FileFinder(util.EXTENSIONS.path, (self.machinery.ExtensionFileLoader, self.machinery.EXTENSION_SUFFIXES)) with warnings.catch_warnings(): @@ -22,7 +21,7 @@ class FinderTests(abc.FinderTests): return importer.find_module(fullname) def test_module(self): - self.assertTrue(self.find_module(util.NAME)) + self.assertTrue(self.find_module(util.EXTENSIONS.name)) # No extension module as an __init__ available for testing. test_package = test_package_in_package = None @@ -36,8 +35,10 @@ class FinderTests(abc.FinderTests): def test_failure(self): self.assertIsNone(self.find_module('asdfjkl;')) -Frozen_FinderTests, Source_FinderTests = test_util.test_both( - FinderTests, machinery=machinery) + +(Frozen_FinderTests, + Source_FinderTests + ) = util.test_both(FinderTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/extension/test_loader.py b/Lib/test/test_importlib/extension/test_loader.py index fd9abf2..aefd050 100644 --- a/Lib/test/test_importlib/extension/test_loader.py +++ b/Lib/test/test_importlib/extension/test_loader.py @@ -1,4 +1,3 @@ -from . import util as ext_util from .. import abc from .. import util @@ -15,8 +14,8 @@ class LoaderTests(abc.LoaderTests): """Test load_module() for extension modules.""" def setUp(self): - self.loader = self.machinery.ExtensionFileLoader(ext_util.NAME, - ext_util.FILEPATH) + self.loader = self.machinery.ExtensionFileLoader(util.EXTENSIONS.name, + util.EXTENSIONS.file_path) def load_module(self, fullname): return self.loader.load_module(fullname) @@ -29,23 +28,23 @@ class LoaderTests(abc.LoaderTests): self.load_module('XXX') def test_equality(self): - other = self.machinery.ExtensionFileLoader(ext_util.NAME, - ext_util.FILEPATH) + other = self.machinery.ExtensionFileLoader(util.EXTENSIONS.name, + util.EXTENSIONS.file_path) self.assertEqual(self.loader, other) def test_inequality(self): - other = self.machinery.ExtensionFileLoader('_' + ext_util.NAME, - ext_util.FILEPATH) + other = self.machinery.ExtensionFileLoader('_' + util.EXTENSIONS.name, + util.EXTENSIONS.file_path) self.assertNotEqual(self.loader, other) def test_module(self): - with util.uncache(ext_util.NAME): - module = self.load_module(ext_util.NAME) - for attr, value in [('__name__', ext_util.NAME), - ('__file__', ext_util.FILEPATH), + with util.uncache(util.EXTENSIONS.name): + module = self.load_module(util.EXTENSIONS.name) + for attr, value in [('__name__', util.EXTENSIONS.name), + ('__file__', util.EXTENSIONS.file_path), ('__package__', '')]: self.assertEqual(getattr(module, attr), value) - self.assertIn(ext_util.NAME, sys.modules) + self.assertIn(util.EXTENSIONS.name, sys.modules) self.assertIsInstance(module.__loader__, self.machinery.ExtensionFileLoader) @@ -56,9 +55,9 @@ class LoaderTests(abc.LoaderTests): test_lacking_parent = None def test_module_reuse(self): - with util.uncache(ext_util.NAME): - module1 = self.load_module(ext_util.NAME) - module2 = self.load_module(ext_util.NAME) + with util.uncache(util.EXTENSIONS.name): + module1 = self.load_module(util.EXTENSIONS.name) + module2 = self.load_module(util.EXTENSIONS.name) self.assertIs(module1, module2) # No easy way to trigger a failure after a successful import. @@ -71,14 +70,15 @@ class LoaderTests(abc.LoaderTests): self.assertEqual(cm.exception.name, name) def test_is_package(self): - self.assertFalse(self.loader.is_package(ext_util.NAME)) + self.assertFalse(self.loader.is_package(util.EXTENSIONS.name)) for suffix in self.machinery.EXTENSION_SUFFIXES: path = os.path.join('some', 'path', 'pkg', '__init__' + suffix) loader = self.machinery.ExtensionFileLoader('pkg', path) self.assertTrue(loader.is_package('pkg')) -Frozen_LoaderTests, Source_LoaderTests = util.test_both( - LoaderTests, machinery=machinery) +(Frozen_LoaderTests, + Source_LoaderTests + ) = util.test_both(LoaderTests, machinery=machinery) diff --git a/Lib/test/test_importlib/extension/test_path_hook.py b/Lib/test/test_importlib/extension/test_path_hook.py index 49d6734..8f4b8bb 100644 --- a/Lib/test/test_importlib/extension/test_path_hook.py +++ b/Lib/test/test_importlib/extension/test_path_hook.py @@ -1,7 +1,6 @@ -from .. import util as test_util -from . import util +from .. import util -machinery = test_util.import_importlib('importlib.machinery') +machinery = util.import_importlib('importlib.machinery') import collections import sys @@ -22,10 +21,12 @@ class PathHookTests: def test_success(self): # Path hook should handle a directory where a known extension module # exists. - self.assertTrue(hasattr(self.hook(util.PATH), 'find_module')) + self.assertTrue(hasattr(self.hook(util.EXTENSIONS.path), 'find_module')) -Frozen_PathHooksTests, Source_PathHooksTests = test_util.test_both( - PathHookTests, machinery=machinery) + +(Frozen_PathHooksTests, + Source_PathHooksTests + ) = util.test_both(PathHookTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/extension/util.py b/Lib/test/test_importlib/extension/util.py deleted file mode 100644 index 8d089f0..0000000 --- a/Lib/test/test_importlib/extension/util.py +++ /dev/null @@ -1,19 +0,0 @@ -from importlib import machinery -import os -import sys - -PATH = None -EXT = None -FILENAME = None -NAME = '_testcapi' -try: - for PATH in sys.path: - for EXT in machinery.EXTENSION_SUFFIXES: - FILENAME = NAME + EXT - FILEPATH = os.path.join(PATH, FILENAME) - if os.path.exists(os.path.join(PATH, FILENAME)): - raise StopIteration - else: - PATH = EXT = FILENAME = FILEPATH = None -except StopIteration: - pass diff --git a/Lib/test/test_importlib/frozen/test_finder.py b/Lib/test/test_importlib/frozen/test_finder.py index f9f97f3..519aa02 100644 --- a/Lib/test/test_importlib/frozen/test_finder.py +++ b/Lib/test/test_importlib/frozen/test_finder.py @@ -37,8 +37,10 @@ class FindSpecTests(abc.FinderTests): spec = self.find('<not real>') self.assertIsNone(spec) -Frozen_FindSpecTests, Source_FindSpecTests = util.test_both(FindSpecTests, - machinery=machinery) + +(Frozen_FindSpecTests, + Source_FindSpecTests + ) = util.test_both(FindSpecTests, machinery=machinery) class FinderTests(abc.FinderTests): @@ -72,8 +74,10 @@ class FinderTests(abc.FinderTests): loader = self.find('<not real>') self.assertIsNone(loader) -Frozen_FinderTests, Source_FinderTests = util.test_both(FinderTests, - machinery=machinery) + +(Frozen_FinderTests, + Source_FinderTests + ) = util.test_both(FinderTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/frozen/test_loader.py b/Lib/test/test_importlib/frozen/test_loader.py index 7c01464..603c7d7 100644 --- a/Lib/test/test_importlib/frozen/test_loader.py +++ b/Lib/test/test_importlib/frozen/test_loader.py @@ -85,8 +85,10 @@ class ExecModuleTests(abc.LoaderTests): self.exec_module('_not_real') self.assertEqual(cm.exception.name, '_not_real') -Frozen_ExecModuleTests, Source_ExecModuleTests = util.test_both(ExecModuleTests, - machinery=machinery) + +(Frozen_ExecModuleTests, + Source_ExecModuleTests + ) = util.test_both(ExecModuleTests, machinery=machinery) class LoaderTests(abc.LoaderTests): @@ -175,8 +177,10 @@ class LoaderTests(abc.LoaderTests): self.machinery.FrozenImporter.load_module('_not_real') self.assertEqual(cm.exception.name, '_not_real') -Frozen_LoaderTests, Source_LoaderTests = util.test_both(LoaderTests, - machinery=machinery) + +(Frozen_LoaderTests, + Source_LoaderTests + ) = util.test_both(LoaderTests, machinery=machinery) class InspectLoaderTests: @@ -214,8 +218,9 @@ class InspectLoaderTests: method('importlib') self.assertEqual(cm.exception.name, 'importlib') -Frozen_ILTests, Source_ILTests = util.test_both(InspectLoaderTests, - machinery=machinery) +(Frozen_ILTests, + Source_ILTests + ) = util.test_both(InspectLoaderTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/test___loader__.py b/Lib/test/test_importlib/import_/test___loader__.py index 6df8010..9998cd6 100644 --- a/Lib/test/test_importlib/import_/test___loader__.py +++ b/Lib/test/test_importlib/import_/test___loader__.py @@ -4,7 +4,6 @@ import types import unittest from .. import util -from . import util as import_util class SpecLoaderMock: @@ -24,8 +23,10 @@ class SpecLoaderAttributeTests: module = self.__import__('blah') self.assertEqual(loader, module.__loader__) -Frozen_SpecTests, Source_SpecTests = util.test_both( - SpecLoaderAttributeTests, __import__=import_util.__import__) + +(Frozen_SpecTests, + Source_SpecTests + ) = util.test_both(SpecLoaderAttributeTests, __import__=util.__import__) class LoaderMock: @@ -62,8 +63,9 @@ class LoaderAttributeTests: self.assertEqual(loader, module.__loader__) -Frozen_Tests, Source_Tests = util.test_both(LoaderAttributeTests, - __import__=import_util.__import__) +(Frozen_Tests, + Source_Tests + ) = util.test_both(LoaderAttributeTests, __import__=util.__import__) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/test___package__.py b/Lib/test/test_importlib/import_/test___package__.py index 2e19725..c7d3a2a 100644 --- a/Lib/test/test_importlib/import_/test___package__.py +++ b/Lib/test/test_importlib/import_/test___package__.py @@ -6,7 +6,6 @@ of using the typical __path__/__name__ test). """ import unittest from .. import util -from . import util as import_util class Using__package__: @@ -70,17 +69,23 @@ class Using__package__: with self.assertRaises(TypeError): self.__import__('', globals, {}, ['relimport'], 1) + class Using__package__PEP302(Using__package__): mock_modules = util.mock_modules -Frozen_UsingPackagePEP302, Source_UsingPackagePEP302 = util.test_both( - Using__package__PEP302, __import__=import_util.__import__) -class Using__package__PEP302(Using__package__): +(Frozen_UsingPackagePEP302, + Source_UsingPackagePEP302 + ) = util.test_both(Using__package__PEP302, __import__=util.__import__) + + +class Using__package__PEP451(Using__package__): mock_modules = util.mock_spec -Frozen_UsingPackagePEP451, Source_UsingPackagePEP451 = util.test_both( - Using__package__PEP302, __import__=import_util.__import__) + +(Frozen_UsingPackagePEP451, + Source_UsingPackagePEP451 + ) = util.test_both(Using__package__PEP451, __import__=util.__import__) class Setting__package__: @@ -95,7 +100,7 @@ class Setting__package__: """ - __import__ = import_util.__import__[1] + __import__ = util.__import__['Source'] # [top-level] def test_top_level(self): diff --git a/Lib/test/test_importlib/import_/test_api.py b/Lib/test/test_importlib/import_/test_api.py index 439c105..2c61b01 100644 --- a/Lib/test/test_importlib/import_/test_api.py +++ b/Lib/test/test_importlib/import_/test_api.py @@ -1,5 +1,4 @@ from .. import util -from . import util as import_util from importlib import machinery import sys @@ -79,15 +78,19 @@ class APITest: class OldAPITests(APITest): bad_finder_loader = BadLoaderFinder -Frozen_OldAPITests, Source_OldAPITests = util.test_both( - OldAPITests, __import__=import_util.__import__) + +(Frozen_OldAPITests, + Source_OldAPITests + ) = util.test_both(OldAPITests, __import__=util.__import__) class SpecAPITests(APITest): bad_finder_loader = BadSpecFinderLoader -Frozen_SpecAPITests, Source_SpecAPITests = util.test_both( - SpecAPITests, __import__=import_util.__import__) + +(Frozen_SpecAPITests, + Source_SpecAPITests + ) = util.test_both(SpecAPITests, __import__=util.__import__) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/test_caching.py b/Lib/test/test_importlib/import_/test_caching.py index c292ee4..8079add 100644 --- a/Lib/test/test_importlib/import_/test_caching.py +++ b/Lib/test/test_importlib/import_/test_caching.py @@ -1,6 +1,5 @@ """Test that sys.modules is used properly by import.""" from .. import util -from . import util as import_util import sys from types import MethodType import unittest @@ -39,15 +38,17 @@ class UseCache: self.__import__(name) self.assertEqual(cm.exception.name, name) -Frozen_UseCache, Source_UseCache = util.test_both( - UseCache, __import__=import_util.__import__) + +(Frozen_UseCache, + Source_UseCache + ) = util.test_both(UseCache, __import__=util.__import__) class ImportlibUseCache(UseCache, unittest.TestCase): # Pertinent only to PEP 302; exec_module() doesn't return a module. - __import__ = import_util.__import__[1] + __import__ = util.__import__['Source'] def create_mock(self, *names, return_=None): mock = util.mock_modules(*names) diff --git a/Lib/test/test_importlib/import_/test_fromlist.py b/Lib/test/test_importlib/import_/test_fromlist.py index a755b75..8045465 100644 --- a/Lib/test/test_importlib/import_/test_fromlist.py +++ b/Lib/test/test_importlib/import_/test_fromlist.py @@ -1,6 +1,5 @@ """Test that the semantics relating to the 'fromlist' argument are correct.""" from .. import util -from . import util as import_util import unittest @@ -29,8 +28,10 @@ class ReturnValue: module = self.__import__('pkg.module', fromlist=['attr']) self.assertEqual(module.__name__, 'pkg.module') -Frozen_ReturnValue, Source_ReturnValue = util.test_both( - ReturnValue, __import__=import_util.__import__) + +(Frozen_ReturnValue, + Source_ReturnValue + ) = util.test_both(ReturnValue, __import__=util.__import__) class HandlingFromlist: @@ -121,8 +122,10 @@ class HandlingFromlist: self.assertEqual(module.module1.__name__, 'pkg.module1') self.assertEqual(module.module2.__name__, 'pkg.module2') -Frozen_FromList, Source_FromList = util.test_both( - HandlingFromlist, __import__=import_util.__import__) + +(Frozen_FromList, + Source_FromList + ) = util.test_both(HandlingFromlist, __import__=util.__import__) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/test_meta_path.py b/Lib/test/test_importlib/import_/test_meta_path.py index 5eeb145..c452cdd 100644 --- a/Lib/test/test_importlib/import_/test_meta_path.py +++ b/Lib/test/test_importlib/import_/test_meta_path.py @@ -1,5 +1,4 @@ from .. import util -from . import util as import_util import importlib._bootstrap import sys from types import MethodType @@ -46,8 +45,10 @@ class CallingOrder: self.assertEqual(len(w), 1) self.assertTrue(issubclass(w[-1].category, ImportWarning)) -Frozen_CallingOrder, Source_CallingOrder = util.test_both( - CallingOrder, __import__=import_util.__import__) + +(Frozen_CallingOrder, + Source_CallingOrder + ) = util.test_both(CallingOrder, __import__=util.__import__) class CallSignature: @@ -100,19 +101,25 @@ class CallSignature: self.assertEqual(args[0], mod_name) self.assertIs(args[1], path) + class CallSignaturePEP302(CallSignature): mock_modules = util.mock_modules finder_name = 'find_module' -Frozen_CallSignaturePEP302, Source_CallSignaturePEP302 = util.test_both( - CallSignaturePEP302, __import__=import_util.__import__) + +(Frozen_CallSignaturePEP302, + Source_CallSignaturePEP302 + ) = util.test_both(CallSignaturePEP302, __import__=util.__import__) + class CallSignaturePEP451(CallSignature): mock_modules = util.mock_spec finder_name = 'find_spec' -Frozen_CallSignaturePEP451, Source_CallSignaturePEP451 = util.test_both( - CallSignaturePEP451, __import__=import_util.__import__) + +(Frozen_CallSignaturePEP451, + Source_CallSignaturePEP451 + ) = util.test_both(CallSignaturePEP451, __import__=util.__import__) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/test_packages.py b/Lib/test/test_importlib/import_/test_packages.py index 55a5d14..3755b84 100644 --- a/Lib/test/test_importlib/import_/test_packages.py +++ b/Lib/test/test_importlib/import_/test_packages.py @@ -1,5 +1,4 @@ from .. import util -from . import util as import_util import sys import unittest import importlib @@ -102,8 +101,10 @@ class ParentModuleTests: finally: support.unload(subname) -Frozen_ParentTests, Source_ParentTests = util.test_both( - ParentModuleTests, __import__=import_util.__import__) + +(Frozen_ParentTests, + Source_ParentTests + ) = util.test_both(ParentModuleTests, __import__=util.__import__) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/test_path.py b/Lib/test/test_importlib/import_/test_path.py index 1274f8c..e86c655 100644 --- a/Lib/test/test_importlib/import_/test_path.py +++ b/Lib/test/test_importlib/import_/test_path.py @@ -1,5 +1,4 @@ from .. import util -from . import util as import_util importlib = util.import_importlib('importlib') machinery = util.import_importlib('importlib.machinery') @@ -58,7 +57,7 @@ class FinderTests: module = '<test module>' path = '<test path>' importer = util.mock_spec(module) - hook = import_util.mock_path_hook(path, importer=importer) + hook = util.mock_path_hook(path, importer=importer) with util.import_state(path_hooks=[hook]): loader = self.machinery.PathFinder.find_module(module, [path]) self.assertIs(loader, importer) @@ -83,7 +82,7 @@ class FinderTests: path = '' module = '<test module>' importer = util.mock_spec(module) - hook = import_util.mock_path_hook(os.getcwd(), importer=importer) + hook = util.mock_path_hook(os.getcwd(), importer=importer) with util.import_state(path=[path], path_hooks=[hook]): loader = self.machinery.PathFinder.find_module(module) self.assertIs(loader, importer) @@ -112,8 +111,57 @@ class FinderTests: if email is not missing: sys.modules['email'] = email -Frozen_FinderTests, Source_FinderTests = util.test_both( - FinderTests, importlib=importlib, machinery=machinery) + def test_finder_with_find_module(self): + class TestFinder: + def find_module(self, fullname): + return self.to_return + failing_finder = TestFinder() + failing_finder.to_return = None + path = 'testing path' + with util.import_state(path_importer_cache={path: failing_finder}): + self.assertIsNone( + self.machinery.PathFinder.find_spec('whatever', [path])) + success_finder = TestFinder() + success_finder.to_return = __loader__ + with util.import_state(path_importer_cache={path: success_finder}): + spec = self.machinery.PathFinder.find_spec('whatever', [path]) + self.assertEqual(spec.loader, __loader__) + + def test_finder_with_find_loader(self): + class TestFinder: + loader = None + portions = [] + def find_loader(self, fullname): + return self.loader, self.portions + path = 'testing path' + with util.import_state(path_importer_cache={path: TestFinder()}): + self.assertIsNone( + self.machinery.PathFinder.find_spec('whatever', [path])) + success_finder = TestFinder() + success_finder.loader = __loader__ + with util.import_state(path_importer_cache={path: success_finder}): + spec = self.machinery.PathFinder.find_spec('whatever', [path]) + self.assertEqual(spec.loader, __loader__) + + def test_finder_with_find_spec(self): + class TestFinder: + spec = None + def find_spec(self, fullname, target=None): + return self.spec + path = 'testing path' + with util.import_state(path_importer_cache={path: TestFinder()}): + self.assertIsNone( + self.machinery.PathFinder.find_spec('whatever', [path])) + success_finder = TestFinder() + success_finder.spec = self.machinery.ModuleSpec('whatever', __loader__) + with util.import_state(path_importer_cache={path: success_finder}): + got = self.machinery.PathFinder.find_spec('whatever', [path]) + self.assertEqual(got, success_finder.spec) + + +(Frozen_FinderTests, + Source_FinderTests + ) = util.test_both(FinderTests, importlib=importlib, machinery=machinery) class PathEntryFinderTests: @@ -136,8 +184,10 @@ class PathEntryFinderTests: path_hooks=[Finder]): self.machinery.PathFinder.find_spec('importlib') -Frozen_PEFTests, Source_PEFTests = util.test_both( - PathEntryFinderTests, machinery=machinery) + +(Frozen_PEFTests, + Source_PEFTests + ) = util.test_both(PathEntryFinderTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/test_relative_imports.py b/Lib/test/test_importlib/import_/test_relative_imports.py index b216e9c..28bb6f7 100644 --- a/Lib/test/test_importlib/import_/test_relative_imports.py +++ b/Lib/test/test_importlib/import_/test_relative_imports.py @@ -1,6 +1,5 @@ """Test relative imports (PEP 328).""" from .. import util -from . import util as import_util import sys import unittest @@ -208,8 +207,10 @@ class RelativeImports: with self.assertRaises(KeyError): self.__import__('sys', level=1) -Frozen_RelativeImports, Source_RelativeImports = util.test_both( - RelativeImports, __import__=import_util.__import__) + +(Frozen_RelativeImports, + Source_RelativeImports + ) = util.test_both(RelativeImports, __import__=util.__import__) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/import_/util.py b/Lib/test/test_importlib/import_/util.py deleted file mode 100644 index dcb490f..0000000 --- a/Lib/test/test_importlib/import_/util.py +++ /dev/null @@ -1,20 +0,0 @@ -from .. import util - -frozen_importlib, source_importlib = util.import_importlib('importlib') - -import builtins -import functools -import importlib -import unittest - - -__import__ = staticmethod(builtins.__import__), staticmethod(source_importlib.__import__) - - -def mock_path_hook(*entries, importer): - """A mock sys.path_hooks entry.""" - def hook(entry): - if entry not in entries: - raise ImportError - return importer - return hook diff --git a/Lib/test/test_importlib/source/test_case_sensitivity.py b/Lib/test/test_importlib/source/test_case_sensitivity.py index efd3146..29e95b2 100644 --- a/Lib/test/test_importlib/source/test_case_sensitivity.py +++ b/Lib/test/test_importlib/source/test_case_sensitivity.py @@ -1,6 +1,5 @@ """Test case-sensitivity (PEP 235).""" from .. import util -from . import util as source_util importlib = util.import_importlib('importlib') machinery = util.import_importlib('importlib.machinery') @@ -32,7 +31,7 @@ class CaseSensitivityTest: """Look for a module with matching and non-matching sensitivity.""" sensitive_pkg = 'sensitive.{0}'.format(self.name) insensitive_pkg = 'insensitive.{0}'.format(self.name.lower()) - context = source_util.create_modules(insensitive_pkg, sensitive_pkg) + context = util.create_modules(insensitive_pkg, sensitive_pkg) with context as mapping: sensitive_path = os.path.join(mapping['.root'], 'sensitive') insensitive_path = os.path.join(mapping['.root'], 'insensitive') @@ -63,20 +62,28 @@ class CaseSensitivityTest: self.assertIsNotNone(insensitive) self.assertIn(self.name, insensitive.get_filename(self.name)) + class CaseSensitivityTestPEP302(CaseSensitivityTest): def find(self, finder): return finder.find_module(self.name) -Frozen_CaseSensitivityTestPEP302, Source_CaseSensitivityTestPEP302 = util.test_both( - CaseSensitivityTestPEP302, importlib=importlib, machinery=machinery) + +(Frozen_CaseSensitivityTestPEP302, + Source_CaseSensitivityTestPEP302 + ) = util.test_both(CaseSensitivityTestPEP302, importlib=importlib, + machinery=machinery) + class CaseSensitivityTestPEP451(CaseSensitivityTest): def find(self, finder): found = finder.find_spec(self.name) return found.loader if found is not None else found -Frozen_CaseSensitivityTestPEP451, Source_CaseSensitivityTestPEP451 = util.test_both( - CaseSensitivityTestPEP451, importlib=importlib, machinery=machinery) + +(Frozen_CaseSensitivityTestPEP451, + Source_CaseSensitivityTestPEP451 + ) = util.test_both(CaseSensitivityTestPEP451, importlib=importlib, + machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/source/test_file_loader.py b/Lib/test/test_importlib/source/test_file_loader.py index 2d415f9..73f4c62 100644 --- a/Lib/test/test_importlib/source/test_file_loader.py +++ b/Lib/test/test_importlib/source/test_file_loader.py @@ -1,6 +1,5 @@ from .. import abc from .. import util -from . import util as source_util importlib = util.import_importlib('importlib') importlib_abc = util.import_importlib('importlib.abc') @@ -71,7 +70,7 @@ class SimpleTest(abc.LoaderTests): # [basic] def test_module(self): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: loader = self.machinery.SourceFileLoader('_temp', mapping['_temp']) with warnings.catch_warnings(): warnings.simplefilter('ignore', DeprecationWarning) @@ -83,7 +82,7 @@ class SimpleTest(abc.LoaderTests): self.assertEqual(getattr(module, attr), value) def test_package(self): - with source_util.create_modules('_pkg.__init__') as mapping: + with util.create_modules('_pkg.__init__') as mapping: loader = self.machinery.SourceFileLoader('_pkg', mapping['_pkg.__init__']) with warnings.catch_warnings(): @@ -98,7 +97,7 @@ class SimpleTest(abc.LoaderTests): def test_lacking_parent(self): - with source_util.create_modules('_pkg.__init__', '_pkg.mod')as mapping: + with util.create_modules('_pkg.__init__', '_pkg.mod')as mapping: loader = self.machinery.SourceFileLoader('_pkg.mod', mapping['_pkg.mod']) with warnings.catch_warnings(): @@ -115,7 +114,7 @@ class SimpleTest(abc.LoaderTests): return lambda name: fxn(name) + 1 def test_module_reuse(self): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: loader = self.machinery.SourceFileLoader('_temp', mapping['_temp']) with warnings.catch_warnings(): warnings.simplefilter('ignore', DeprecationWarning) @@ -139,7 +138,7 @@ class SimpleTest(abc.LoaderTests): attributes = ('__file__', '__path__', '__package__') value = '<test>' name = '_temp' - with source_util.create_modules(name) as mapping: + with util.create_modules(name) as mapping: orig_module = types.ModuleType(name) for attr in attributes: setattr(orig_module, attr, value) @@ -159,7 +158,7 @@ class SimpleTest(abc.LoaderTests): # [syntax error] def test_bad_syntax(self): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: with open(mapping['_temp'], 'w') as file: file.write('=') loader = self.machinery.SourceFileLoader('_temp', mapping['_temp']) @@ -190,11 +189,11 @@ class SimpleTest(abc.LoaderTests): if os.path.exists(pycache): shutil.rmtree(pycache) - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_timestamp_overflow(self): # When a modification timestamp is larger than 2**32, it should be # truncated rather than raise an OverflowError. - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: source = mapping['_temp'] compiled = self.util.cache_from_source(source) with open(source, 'w') as f: @@ -236,9 +235,11 @@ class SimpleTest(abc.LoaderTests): warnings.simplefilter('ignore', DeprecationWarning) loader.load_module('bad name') -Frozen_SimpleTest, Source_SimpleTest = util.test_both( - SimpleTest, importlib=importlib, machinery=machinery, abc=importlib_abc, - util=importlib_util) + +(Frozen_SimpleTest, + Source_SimpleTest + ) = util.test_both(SimpleTest, importlib=importlib, machinery=machinery, + abc=importlib_abc, util=importlib_util) class BadBytecodeTest: @@ -275,45 +276,45 @@ class BadBytecodeTest: return bytecode_path def _test_empty_file(self, test, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bc_path = self.manipulate_bytecode('_temp', mapping, lambda bc: b'', del_source=del_source) test('_temp', mapping, bc_path) - @source_util.writes_bytecode_files + @util.writes_bytecode_files def _test_partial_magic(self, test, *, del_source=False): # When their are less than 4 bytes to a .pyc, regenerate it if # possible, else raise ImportError. - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bc_path = self.manipulate_bytecode('_temp', mapping, lambda bc: bc[:3], del_source=del_source) test('_temp', mapping, bc_path) def _test_magic_only(self, test, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bc_path = self.manipulate_bytecode('_temp', mapping, lambda bc: bc[:4], del_source=del_source) test('_temp', mapping, bc_path) def _test_partial_timestamp(self, test, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bc_path = self.manipulate_bytecode('_temp', mapping, lambda bc: bc[:7], del_source=del_source) test('_temp', mapping, bc_path) def _test_partial_size(self, test, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bc_path = self.manipulate_bytecode('_temp', mapping, lambda bc: bc[:11], del_source=del_source) test('_temp', mapping, bc_path) def _test_no_marshal(self, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bc_path = self.manipulate_bytecode('_temp', mapping, lambda bc: bc[:12], del_source=del_source) @@ -322,7 +323,7 @@ class BadBytecodeTest: self.import_(file_path, '_temp') def _test_non_code_marshal(self, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bytecode_path = self.manipulate_bytecode('_temp', mapping, lambda bc: bc[:12] + marshal.dumps(b'abcd'), del_source=del_source) @@ -333,7 +334,7 @@ class BadBytecodeTest: self.assertEqual(cm.exception.path, bytecode_path) def _test_bad_marshal(self, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bytecode_path = self.manipulate_bytecode('_temp', mapping, lambda bc: bc[:12] + b'<test>', del_source=del_source) @@ -342,11 +343,12 @@ class BadBytecodeTest: self.import_(file_path, '_temp') def _test_bad_magic(self, test, *, del_source=False): - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: bc_path = self.manipulate_bytecode('_temp', mapping, lambda bc: b'\x00\x00\x00\x00' + bc[4:]) test('_temp', mapping, bc_path) + class BadBytecodeTestPEP451(BadBytecodeTest): def import_(self, file, module_name): @@ -355,6 +357,7 @@ class BadBytecodeTestPEP451(BadBytecodeTest): module.__spec__ = self.util.spec_from_loader(module_name, loader) loader.exec_module(module) + class BadBytecodeTestPEP302(BadBytecodeTest): def import_(self, file, module_name): @@ -371,7 +374,7 @@ class SourceLoaderBadBytecodeTest: def setUpClass(cls): cls.loader = cls.machinery.SourceFileLoader - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_empty_file(self): # When a .pyc is empty, regenerate it if possible, else raise # ImportError. @@ -390,7 +393,7 @@ class SourceLoaderBadBytecodeTest: self._test_partial_magic(test) - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_magic_only(self): # When there is only the magic number, regenerate the .pyc if possible, # else raise EOFError. @@ -401,7 +404,7 @@ class SourceLoaderBadBytecodeTest: self._test_magic_only(test) - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_bad_magic(self): # When the magic number is different, the bytecode should be # regenerated. @@ -413,7 +416,7 @@ class SourceLoaderBadBytecodeTest: self._test_bad_magic(test) - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_partial_timestamp(self): # When the timestamp is partial, regenerate the .pyc, else # raise EOFError. @@ -424,7 +427,7 @@ class SourceLoaderBadBytecodeTest: self._test_partial_timestamp(test) - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_partial_size(self): # When the size is partial, regenerate the .pyc, else # raise EOFError. @@ -435,29 +438,29 @@ class SourceLoaderBadBytecodeTest: self._test_partial_size(test) - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_no_marshal(self): # When there is only the magic number and timestamp, raise EOFError. self._test_no_marshal() - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_non_code_marshal(self): self._test_non_code_marshal() # XXX ImportError when sourceless # [bad marshal] - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_bad_marshal(self): # Bad marshal data should raise a ValueError. self._test_bad_marshal() # [bad timestamp] - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_old_timestamp(self): # When the timestamp is older than the source, bytecode should be # regenerated. zeros = b'\x00\x00\x00\x00' - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: py_compile.compile(mapping['_temp']) bytecode_path = self.util.cache_from_source(mapping['_temp']) with open(bytecode_path, 'r+b') as bytecode_file: @@ -471,10 +474,10 @@ class SourceLoaderBadBytecodeTest: self.assertEqual(bytecode_file.read(4), source_timestamp) # [bytecode read-only] - @source_util.writes_bytecode_files + @util.writes_bytecode_files def test_read_only_bytecode(self): # When bytecode is read-only but should be rewritten, fail silently. - with source_util.create_modules('_temp') as mapping: + with util.create_modules('_temp') as mapping: # Create bytecode that will need to be re-created. py_compile.compile(mapping['_temp']) bytecode_path = self.util.cache_from_source(mapping['_temp']) @@ -491,21 +494,29 @@ class SourceLoaderBadBytecodeTest: # Make writable for eventual clean-up. os.chmod(bytecode_path, stat.S_IWUSR) + class SourceLoaderBadBytecodeTestPEP451( SourceLoaderBadBytecodeTest, BadBytecodeTestPEP451): pass -Frozen_SourceBadBytecodePEP451, Source_SourceBadBytecodePEP451 = util.test_both( - SourceLoaderBadBytecodeTestPEP451, importlib=importlib, machinery=machinery, - abc=importlib_abc, util=importlib_util) + +(Frozen_SourceBadBytecodePEP451, + Source_SourceBadBytecodePEP451 + ) = util.test_both(SourceLoaderBadBytecodeTestPEP451, importlib=importlib, + machinery=machinery, abc=importlib_abc, + util=importlib_util) + class SourceLoaderBadBytecodeTestPEP302( SourceLoaderBadBytecodeTest, BadBytecodeTestPEP302): pass -Frozen_SourceBadBytecodePEP302, Source_SourceBadBytecodePEP302 = util.test_both( - SourceLoaderBadBytecodeTestPEP302, importlib=importlib, machinery=machinery, - abc=importlib_abc, util=importlib_util) + +(Frozen_SourceBadBytecodePEP302, + Source_SourceBadBytecodePEP302 + ) = util.test_both(SourceLoaderBadBytecodeTestPEP302, importlib=importlib, + machinery=machinery, abc=importlib_abc, + util=importlib_util) class SourcelessLoaderBadBytecodeTest: @@ -567,21 +578,29 @@ class SourcelessLoaderBadBytecodeTest: def test_non_code_marshal(self): self._test_non_code_marshal(del_source=True) + class SourcelessLoaderBadBytecodeTestPEP451(SourcelessLoaderBadBytecodeTest, BadBytecodeTestPEP451): pass -Frozen_SourcelessBadBytecodePEP451, Source_SourcelessBadBytecodePEP451 = util.test_both( - SourcelessLoaderBadBytecodeTestPEP451, importlib=importlib, - machinery=machinery, abc=importlib_abc, util=importlib_util) + +(Frozen_SourcelessBadBytecodePEP451, + Source_SourcelessBadBytecodePEP451 + ) = util.test_both(SourcelessLoaderBadBytecodeTestPEP451, importlib=importlib, + machinery=machinery, abc=importlib_abc, + util=importlib_util) + class SourcelessLoaderBadBytecodeTestPEP302(SourcelessLoaderBadBytecodeTest, BadBytecodeTestPEP302): pass -Frozen_SourcelessBadBytecodePEP302, Source_SourcelessBadBytecodePEP302 = util.test_both( - SourcelessLoaderBadBytecodeTestPEP302, importlib=importlib, - machinery=machinery, abc=importlib_abc, util=importlib_util) + +(Frozen_SourcelessBadBytecodePEP302, + Source_SourcelessBadBytecodePEP302 + ) = util.test_both(SourcelessLoaderBadBytecodeTestPEP302, importlib=importlib, + machinery=machinery, abc=importlib_abc, + util=importlib_util) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/source/test_finder.py b/Lib/test/test_importlib/source/test_finder.py index 473297b..f372b85 100644 --- a/Lib/test/test_importlib/source/test_finder.py +++ b/Lib/test/test_importlib/source/test_finder.py @@ -1,6 +1,5 @@ from .. import abc from .. import util -from . import util as source_util machinery = util.import_importlib('importlib.machinery') @@ -60,7 +59,7 @@ class FinderTests(abc.FinderTests): """ if create is None: create = {test} - with source_util.create_modules(*create) as mapping: + with util.create_modules(*create) as mapping: if compile_: for name in compile_: py_compile.compile(mapping[name]) @@ -100,14 +99,14 @@ class FinderTests(abc.FinderTests): # [sub module] def test_module_in_package(self): - with source_util.create_modules('pkg.__init__', 'pkg.sub') as mapping: + with util.create_modules('pkg.__init__', 'pkg.sub') as mapping: pkg_dir = os.path.dirname(mapping['pkg.__init__']) loader = self.import_(pkg_dir, 'pkg.sub') self.assertTrue(hasattr(loader, 'load_module')) # [sub package] def test_package_in_package(self): - context = source_util.create_modules('pkg.__init__', 'pkg.sub.__init__') + context = util.create_modules('pkg.__init__', 'pkg.sub.__init__') with context as mapping: pkg_dir = os.path.dirname(mapping['pkg.__init__']) loader = self.import_(pkg_dir, 'pkg.sub') @@ -120,7 +119,7 @@ class FinderTests(abc.FinderTests): self.assertIn('__init__', loader.get_filename(name)) def test_failure(self): - with source_util.create_modules('blah') as mapping: + with util.create_modules('blah') as mapping: nothing = self.import_(mapping['.root'], 'sdfsadsadf') self.assertIsNone(nothing) @@ -147,7 +146,7 @@ class FinderTests(abc.FinderTests): # Regression test for http://bugs.python.org/issue14846 def test_dir_removal_handling(self): mod = 'mod' - with source_util.create_modules(mod) as mapping: + with util.create_modules(mod) as mapping: finder = self.get_finder(mapping['.root']) found = self._find(finder, 'mod', loader_only=True) self.assertIsNotNone(found) @@ -196,8 +195,10 @@ class FinderTestsPEP451(FinderTests): spec = finder.find_spec(name) return spec.loader if spec is not None else spec -Frozen_FinderTestsPEP451, Source_FinderTestsPEP451 = util.test_both( - FinderTestsPEP451, machinery=machinery) + +(Frozen_FinderTestsPEP451, + Source_FinderTestsPEP451 + ) = util.test_both(FinderTestsPEP451, machinery=machinery) class FinderTestsPEP420(FinderTests): @@ -210,8 +211,10 @@ class FinderTestsPEP420(FinderTests): loader_portions = finder.find_loader(name) return loader_portions[0] if loader_only else loader_portions -Frozen_FinderTestsPEP420, Source_FinderTestsPEP420 = util.test_both( - FinderTestsPEP420, machinery=machinery) + +(Frozen_FinderTestsPEP420, + Source_FinderTestsPEP420 + ) = util.test_both(FinderTestsPEP420, machinery=machinery) class FinderTestsPEP302(FinderTests): @@ -223,9 +226,10 @@ class FinderTestsPEP302(FinderTests): warnings.simplefilter("ignore", DeprecationWarning) return finder.find_module(name) -Frozen_FinderTestsPEP302, Source_FinderTestsPEP302 = util.test_both( - FinderTestsPEP302, machinery=machinery) +(Frozen_FinderTestsPEP302, + Source_FinderTestsPEP302 + ) = util.test_both(FinderTestsPEP302, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/source/test_path_hook.py b/Lib/test/test_importlib/source/test_path_hook.py index 92da772..e6a2415 100644 --- a/Lib/test/test_importlib/source/test_path_hook.py +++ b/Lib/test/test_importlib/source/test_path_hook.py @@ -1,5 +1,4 @@ from .. import util -from . import util as source_util machinery = util.import_importlib('importlib.machinery') @@ -15,7 +14,7 @@ class PathHookTest: self.machinery.SOURCE_SUFFIXES)) def test_success(self): - with source_util.create_modules('dummy') as mapping: + with util.create_modules('dummy') as mapping: self.assertTrue(hasattr(self.path_hook()(mapping['.root']), 'find_module')) @@ -23,7 +22,10 @@ class PathHookTest: # The empty string represents the cwd. self.assertTrue(hasattr(self.path_hook()(''), 'find_module')) -Frozen_PathHookTest, Source_PathHooktest = util.test_both(PathHookTest, machinery=machinery) + +(Frozen_PathHookTest, + Source_PathHooktest + ) = util.test_both(PathHookTest, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/source/test_source_encoding.py b/Lib/test/test_importlib/source/test_source_encoding.py index c62dfa1..b604afb 100644 --- a/Lib/test/test_importlib/source/test_source_encoding.py +++ b/Lib/test/test_importlib/source/test_source_encoding.py @@ -1,5 +1,4 @@ from .. import util -from . import util as source_util machinery = util.import_importlib('importlib.machinery') @@ -37,7 +36,7 @@ class EncodingTest: module_name = '_temp' def run_test(self, source): - with source_util.create_modules(self.module_name) as mapping: + with util.create_modules(self.module_name) as mapping: with open(mapping[self.module_name], 'wb') as file: file.write(source) loader = self.machinery.SourceFileLoader(self.module_name, @@ -89,6 +88,7 @@ class EncodingTest: with self.assertRaises(SyntaxError): self.run_test(source) + class EncodingTestPEP451(EncodingTest): def load(self, loader): @@ -97,8 +97,11 @@ class EncodingTestPEP451(EncodingTest): loader.exec_module(module) return module -Frozen_EncodingTestPEP451, Source_EncodingTestPEP451 = util.test_both( - EncodingTestPEP451, machinery=machinery) + +(Frozen_EncodingTestPEP451, + Source_EncodingTestPEP451 + ) = util.test_both(EncodingTestPEP451, machinery=machinery) + class EncodingTestPEP302(EncodingTest): @@ -107,8 +110,10 @@ class EncodingTestPEP302(EncodingTest): warnings.simplefilter('ignore', DeprecationWarning) return loader.load_module(self.module_name) -Frozen_EncodingTestPEP302, Source_EncodingTestPEP302 = util.test_both( - EncodingTestPEP302, machinery=machinery) + +(Frozen_EncodingTestPEP302, + Source_EncodingTestPEP302 + ) = util.test_both(EncodingTestPEP302, machinery=machinery) class LineEndingTest: @@ -120,7 +125,7 @@ class LineEndingTest: module_name = '_temp' source_lines = [b"a = 42", b"b = -13", b''] source = line_ending.join(source_lines) - with source_util.create_modules(module_name) as mapping: + with util.create_modules(module_name) as mapping: with open(mapping[module_name], 'wb') as file: file.write(source) loader = self.machinery.SourceFileLoader(module_name, @@ -139,6 +144,7 @@ class LineEndingTest: def test_lf(self): self.run_test(b'\n') + class LineEndingTestPEP451(LineEndingTest): def load(self, loader, module_name): @@ -147,8 +153,11 @@ class LineEndingTestPEP451(LineEndingTest): loader.exec_module(module) return module -Frozen_LineEndingTestPEP451, Source_LineEndingTestPEP451 = util.test_both( - LineEndingTestPEP451, machinery=machinery) + +(Frozen_LineEndingTestPEP451, + Source_LineEndingTestPEP451 + ) = util.test_both(LineEndingTestPEP451, machinery=machinery) + class LineEndingTestPEP302(LineEndingTest): @@ -157,8 +166,10 @@ class LineEndingTestPEP302(LineEndingTest): warnings.simplefilter('ignore', DeprecationWarning) return loader.load_module(module_name) -Frozen_LineEndingTestPEP302, Source_LineEndingTestPEP302 = util.test_both( - LineEndingTestPEP302, machinery=machinery) + +(Frozen_LineEndingTestPEP302, + Source_LineEndingTestPEP302 + ) = util.test_both(LineEndingTestPEP302, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/source/util.py b/Lib/test/test_importlib/source/util.py deleted file mode 100644 index 63cd25a..0000000 --- a/Lib/test/test_importlib/source/util.py +++ /dev/null @@ -1,96 +0,0 @@ -from .. import util -import contextlib -import errno -import functools -import os -import os.path -import sys -import tempfile -from test import support - - -def writes_bytecode_files(fxn): - """Decorator to protect sys.dont_write_bytecode from mutation and to skip - tests that require it to be set to False.""" - if sys.dont_write_bytecode: - return lambda *args, **kwargs: None - @functools.wraps(fxn) - def wrapper(*args, **kwargs): - original = sys.dont_write_bytecode - sys.dont_write_bytecode = False - try: - to_return = fxn(*args, **kwargs) - finally: - sys.dont_write_bytecode = original - return to_return - return wrapper - - -def ensure_bytecode_path(bytecode_path): - """Ensure that the __pycache__ directory for PEP 3147 pyc file exists. - - :param bytecode_path: File system path to PEP 3147 pyc file. - """ - try: - os.mkdir(os.path.dirname(bytecode_path)) - except OSError as error: - if error.errno != errno.EEXIST: - raise - - -@contextlib.contextmanager -def create_modules(*names): - """Temporarily create each named module with an attribute (named 'attr') - that contains the name passed into the context manager that caused the - creation of the module. - - All files are created in a temporary directory returned by - tempfile.mkdtemp(). This directory is inserted at the beginning of - sys.path. When the context manager exits all created files (source and - bytecode) are explicitly deleted. - - No magic is performed when creating packages! This means that if you create - a module within a package you must also create the package's __init__ as - well. - - """ - source = 'attr = {0!r}' - created_paths = [] - mapping = {} - state_manager = None - uncache_manager = None - try: - temp_dir = tempfile.mkdtemp() - mapping['.root'] = temp_dir - import_names = set() - for name in names: - if not name.endswith('__init__'): - import_name = name - else: - import_name = name[:-len('.__init__')] - import_names.add(import_name) - if import_name in sys.modules: - del sys.modules[import_name] - name_parts = name.split('.') - file_path = temp_dir - for directory in name_parts[:-1]: - file_path = os.path.join(file_path, directory) - if not os.path.exists(file_path): - os.mkdir(file_path) - created_paths.append(file_path) - file_path = os.path.join(file_path, name_parts[-1] + '.py') - with open(file_path, 'w') as file: - file.write(source.format(name)) - created_paths.append(file_path) - mapping[name] = file_path - uncache_manager = util.uncache(*import_names) - uncache_manager.__enter__() - state_manager = util.import_state(path=[temp_dir]) - state_manager.__enter__() - yield mapping - finally: - if state_manager is not None: - state_manager.__exit__(None, None, None) - if uncache_manager is not None: - uncache_manager.__exit__(None, None, None) - support.rmtree(temp_dir) diff --git a/Lib/test/test_importlib/test_abc.py b/Lib/test/test_importlib/test_abc.py index a1f8e76..d4bf915 100644 --- a/Lib/test/test_importlib/test_abc.py +++ b/Lib/test/test_importlib/test_abc.py @@ -10,12 +10,13 @@ import unittest from unittest import mock import warnings -from . import util +from . import util as test_util + +init = test_util.import_importlib('importlib') +abc = test_util.import_importlib('importlib.abc') +machinery = test_util.import_importlib('importlib.machinery') +util = test_util.import_importlib('importlib.util') -frozen_init, source_init = util.import_importlib('importlib') -frozen_abc, source_abc = util.import_importlib('importlib.abc') -machinery = util.import_importlib('importlib.machinery') -frozen_util, source_util = util.import_importlib('importlib.util') ##### Inheritance ############################################################## class InheritanceTests: @@ -26,8 +27,7 @@ class InheritanceTests: subclasses = [] superclasses = [] - def __init__(self, *args, **kwargs): - super().__init__(*args, **kwargs) + def setUp(self): self.superclasses = [getattr(self.abc, class_name) for class_name in self.superclass_names] if hasattr(self, 'subclass_names'): @@ -36,11 +36,11 @@ class InheritanceTests: # checking across module boundaries (i.e. the _bootstrap in abc is # not the same as the one in machinery). That means stealing one of # the modules from the other to make sure the same instance is used. - self.subclasses = [getattr(self.abc.machinery, class_name) - for class_name in self.subclass_names] + machinery = self.abc.machinery + self.subclasses = [getattr(machinery, class_name) + for class_name in self.subclass_names] assert self.subclasses or self.superclasses, self.__class__ - testing = self.__class__.__name__.partition('_')[2] - self.__test = getattr(self.abc, testing) + self.__test = getattr(self.abc, self._NAME) def test_subclasses(self): # Test that the expected subclasses inherit. @@ -54,94 +54,97 @@ class InheritanceTests: self.assertTrue(issubclass(self.__test, superclass), "{0} is not a superclass of {1}".format(superclass, self.__test)) -def create_inheritance_tests(base_class): - def set_frozen(ns): - ns['abc'] = frozen_abc - def set_source(ns): - ns['abc'] = source_abc - - classes = [] - for prefix, ns_set in [('Frozen', set_frozen), ('Source', set_source)]: - classes.append(types.new_class('_'.join([prefix, base_class.__name__]), - (base_class, unittest.TestCase), - exec_body=ns_set)) - return classes - class MetaPathFinder(InheritanceTests): superclass_names = ['Finder'] subclass_names = ['BuiltinImporter', 'FrozenImporter', 'PathFinder', 'WindowsRegistryFinder'] -tests = create_inheritance_tests(MetaPathFinder) -Frozen_MetaPathFinderInheritanceTests, Source_MetaPathFinderInheritanceTests = tests + +(Frozen_MetaPathFinderInheritanceTests, + Source_MetaPathFinderInheritanceTests + ) = test_util.test_both(MetaPathFinder, abc=abc) class PathEntryFinder(InheritanceTests): superclass_names = ['Finder'] subclass_names = ['FileFinder'] -tests = create_inheritance_tests(PathEntryFinder) -Frozen_PathEntryFinderInheritanceTests, Source_PathEntryFinderInheritanceTests = tests + +(Frozen_PathEntryFinderInheritanceTests, + Source_PathEntryFinderInheritanceTests + ) = test_util.test_both(PathEntryFinder, abc=abc) class ResourceLoader(InheritanceTests): superclass_names = ['Loader'] -tests = create_inheritance_tests(ResourceLoader) -Frozen_ResourceLoaderInheritanceTests, Source_ResourceLoaderInheritanceTests = tests + +(Frozen_ResourceLoaderInheritanceTests, + Source_ResourceLoaderInheritanceTests + ) = test_util.test_both(ResourceLoader, abc=abc) class InspectLoader(InheritanceTests): superclass_names = ['Loader'] subclass_names = ['BuiltinImporter', 'FrozenImporter', 'ExtensionFileLoader'] -tests = create_inheritance_tests(InspectLoader) -Frozen_InspectLoaderInheritanceTests, Source_InspectLoaderInheritanceTests = tests + +(Frozen_InspectLoaderInheritanceTests, + Source_InspectLoaderInheritanceTests + ) = test_util.test_both(InspectLoader, abc=abc) class ExecutionLoader(InheritanceTests): superclass_names = ['InspectLoader'] subclass_names = ['ExtensionFileLoader'] -tests = create_inheritance_tests(ExecutionLoader) -Frozen_ExecutionLoaderInheritanceTests, Source_ExecutionLoaderInheritanceTests = tests + +(Frozen_ExecutionLoaderInheritanceTests, + Source_ExecutionLoaderInheritanceTests + ) = test_util.test_both(ExecutionLoader, abc=abc) class FileLoader(InheritanceTests): superclass_names = ['ResourceLoader', 'ExecutionLoader'] subclass_names = ['SourceFileLoader', 'SourcelessFileLoader'] -tests = create_inheritance_tests(FileLoader) -Frozen_FileLoaderInheritanceTests, Source_FileLoaderInheritanceTests = tests + +(Frozen_FileLoaderInheritanceTests, + Source_FileLoaderInheritanceTests + ) = test_util.test_both(FileLoader, abc=abc) class SourceLoader(InheritanceTests): superclass_names = ['ResourceLoader', 'ExecutionLoader'] subclass_names = ['SourceFileLoader'] -tests = create_inheritance_tests(SourceLoader) -Frozen_SourceLoaderInheritanceTests, Source_SourceLoaderInheritanceTests = tests + +(Frozen_SourceLoaderInheritanceTests, + Source_SourceLoaderInheritanceTests + ) = test_util.test_both(SourceLoader, abc=abc) + ##### Default return values #################################################### -def make_abc_subclasses(base_class): - classes = [] - for kind, abc in [('Frozen', frozen_abc), ('Source', source_abc)]: - name = '_'.join([kind, base_class.__name__]) - base_classes = base_class, getattr(abc, base_class.__name__) - classes.append(types.new_class(name, base_classes)) - return classes - -def make_return_value_tests(base_class, test_class): - frozen_class, source_class = make_abc_subclasses(base_class) - tests = [] - for prefix, class_in_test in [('Frozen', frozen_class), ('Source', source_class)]: - def set_ns(ns): - ns['ins'] = class_in_test() - tests.append(types.new_class('_'.join([prefix, test_class.__name__]), - (test_class, unittest.TestCase), - exec_body=set_ns)) - return tests + +def make_abc_subclasses(base_class, name=None, inst=False, **kwargs): + if name is None: + name = base_class.__name__ + base = {kind: getattr(splitabc, name) + for kind, splitabc in abc.items()} + return {cls._KIND: cls() if inst else cls + for cls in test_util.split_frozen(base_class, base, **kwargs)} + + +class ABCTestHarness: + + @property + def ins(self): + # Lazily set ins on the class. + cls = self.SPLIT[self._KIND] + ins = cls() + self.__class__.ins = ins + return ins class MetaPathFinder: @@ -149,10 +152,10 @@ class MetaPathFinder: def find_module(self, fullname, path): return super().find_module(fullname, path) -Frozen_MPF, Source_MPF = make_abc_subclasses(MetaPathFinder) +class MetaPathFinderDefaultsTests(ABCTestHarness): -class MetaPathFinderDefaultsTests: + SPLIT = make_abc_subclasses(MetaPathFinder) def test_find_module(self): # Default should return None. @@ -163,8 +166,9 @@ class MetaPathFinderDefaultsTests: self.ins.invalidate_caches() -tests = make_return_value_tests(MetaPathFinder, MetaPathFinderDefaultsTests) -Frozen_MPFDefaultTests, Source_MPFDefaultTests = tests +(Frozen_MPFDefaultTests, + Source_MPFDefaultTests + ) = test_util.test_both(MetaPathFinderDefaultsTests) class PathEntryFinder: @@ -172,10 +176,10 @@ class PathEntryFinder: def find_loader(self, fullname): return super().find_loader(fullname) -Frozen_PEF, Source_PEF = make_abc_subclasses(PathEntryFinder) +class PathEntryFinderDefaultsTests(ABCTestHarness): -class PathEntryFinderDefaultsTests: + SPLIT = make_abc_subclasses(PathEntryFinder) def test_find_loader(self): self.assertEqual((None, []), self.ins.find_loader('something')) @@ -188,8 +192,9 @@ class PathEntryFinderDefaultsTests: self.ins.invalidate_caches() -tests = make_return_value_tests(PathEntryFinder, PathEntryFinderDefaultsTests) -Frozen_PEFDefaultTests, Source_PEFDefaultTests = tests +(Frozen_PEFDefaultTests, + Source_PEFDefaultTests + ) = test_util.test_both(PathEntryFinderDefaultsTests) class Loader: @@ -198,10 +203,9 @@ class Loader: return super().load_module(fullname) -Frozen_L, Source_L = make_abc_subclasses(Loader) +class LoaderDefaultsTests(ABCTestHarness): - -class LoaderDefaultsTests: + SPLIT = make_abc_subclasses(Loader) def test_load_module(self): with self.assertRaises(ImportError): @@ -217,8 +221,9 @@ class LoaderDefaultsTests: self.assertTrue(repr(mod)) -tests = make_return_value_tests(Loader, LoaderDefaultsTests) -Frozen_LDefaultTests, SourceLDefaultTests = tests +(Frozen_LDefaultTests, + SourceLDefaultTests + ) = test_util.test_both(LoaderDefaultsTests) class ResourceLoader(Loader): @@ -227,18 +232,18 @@ class ResourceLoader(Loader): return super().get_data(path) -Frozen_RL, Source_RL = make_abc_subclasses(ResourceLoader) - +class ResourceLoaderDefaultsTests(ABCTestHarness): -class ResourceLoaderDefaultsTests: + SPLIT = make_abc_subclasses(ResourceLoader) def test_get_data(self): with self.assertRaises(IOError): self.ins.get_data('/some/path') -tests = make_return_value_tests(ResourceLoader, ResourceLoaderDefaultsTests) -Frozen_RLDefaultTests, Source_RLDefaultTests = tests +(Frozen_RLDefaultTests, + Source_RLDefaultTests + ) = test_util.test_both(ResourceLoaderDefaultsTests) class InspectLoader(Loader): @@ -250,10 +255,12 @@ class InspectLoader(Loader): return super().get_source(fullname) -Frozen_IL, Source_IL = make_abc_subclasses(InspectLoader) +SPLIT_IL = make_abc_subclasses(InspectLoader) -class InspectLoaderDefaultsTests: +class InspectLoaderDefaultsTests(ABCTestHarness): + + SPLIT = SPLIT_IL def test_is_package(self): with self.assertRaises(ImportError): @@ -264,8 +271,9 @@ class InspectLoaderDefaultsTests: self.ins.get_source('blah') -tests = make_return_value_tests(InspectLoader, InspectLoaderDefaultsTests) -Frozen_ILDefaultTests, Source_ILDefaultTests = tests +(Frozen_ILDefaultTests, + Source_ILDefaultTests + ) = test_util.test_both(InspectLoaderDefaultsTests) class ExecutionLoader(InspectLoader): @@ -273,21 +281,25 @@ class ExecutionLoader(InspectLoader): def get_filename(self, fullname): return super().get_filename(fullname) -Frozen_EL, Source_EL = make_abc_subclasses(ExecutionLoader) + +SPLIT_EL = make_abc_subclasses(ExecutionLoader) -class ExecutionLoaderDefaultsTests: +class ExecutionLoaderDefaultsTests(ABCTestHarness): + + SPLIT = SPLIT_EL def test_get_filename(self): with self.assertRaises(ImportError): self.ins.get_filename('blah') -tests = make_return_value_tests(ExecutionLoader, InspectLoaderDefaultsTests) -Frozen_ELDefaultTests, Source_ELDefaultsTests = tests +(Frozen_ELDefaultTests, + Source_ELDefaultsTests + ) = test_util.test_both(InspectLoaderDefaultsTests) -##### MetaPathFinder concrete methods ########################################## +##### MetaPathFinder concrete methods ########################################## class MetaPathFinderFindModuleTests: @classmethod @@ -317,13 +329,12 @@ class MetaPathFinderFindModuleTests: self.assertIs(found, spec.loader) -Frozen_MPFFindModuleTests, Source_MPFFindModuleTests = util.test_both( - MetaPathFinderFindModuleTests, - abc=(frozen_abc, source_abc), - util=(frozen_util, source_util)) +(Frozen_MPFFindModuleTests, + Source_MPFFindModuleTests + ) = test_util.test_both(MetaPathFinderFindModuleTests, abc=abc, util=util) -##### PathEntryFinder concrete methods ######################################### +##### PathEntryFinder concrete methods ######################################### class PathEntryFinderFindLoaderTests: @classmethod @@ -361,11 +372,10 @@ class PathEntryFinderFindLoaderTests: self.assertEqual(paths, found[1]) -Frozen_PEFFindLoaderTests, Source_PEFFindLoaderTests = util.test_both( - PathEntryFinderFindLoaderTests, - abc=(frozen_abc, source_abc), - machinery=machinery, - util=(frozen_util, source_util)) +(Frozen_PEFFindLoaderTests, + Source_PEFFindLoaderTests + ) = test_util.test_both(PathEntryFinderFindLoaderTests, abc=abc, util=util, + machinery=machinery) ##### Loader concrete methods ################################################## @@ -386,7 +396,7 @@ class LoaderLoadModuleTests: def test_fresh(self): loader = self.loader() name = 'blah' - with util.uncache(name): + with test_util.uncache(name): loader.load_module(name) module = loader.found self.assertIs(sys.modules[name], module) @@ -404,7 +414,7 @@ class LoaderLoadModuleTests: module = types.ModuleType(name) module.__spec__ = self.util.spec_from_loader(name, loader) module.__loader__ = loader - with util.uncache(name): + with test_util.uncache(name): sys.modules[name] = module loader.load_module(name) found = loader.found @@ -412,10 +422,9 @@ class LoaderLoadModuleTests: self.assertIs(module, sys.modules[name]) -Frozen_LoaderLoadModuleTests, Source_LoaderLoadModuleTests = util.test_both( - LoaderLoadModuleTests, - abc=(frozen_abc, source_abc), - util=(frozen_util, source_util)) +(Frozen_LoaderLoadModuleTests, + Source_LoaderLoadModuleTests + ) = test_util.test_both(LoaderLoadModuleTests, abc=abc, util=util) ##### InspectLoader concrete methods ########################################### @@ -461,11 +470,10 @@ class InspectLoaderSourceToCodeTests: self.assertEqual(code.co_filename, '<string>') -class Frozen_ILSourceToCodeTests(InspectLoaderSourceToCodeTests, unittest.TestCase): - InspectLoaderSubclass = Frozen_IL - -class Source_ILSourceToCodeTests(InspectLoaderSourceToCodeTests, unittest.TestCase): - InspectLoaderSubclass = Source_IL +(Frozen_ILSourceToCodeTests, + Source_ILSourceToCodeTests + ) = test_util.test_both(InspectLoaderSourceToCodeTests, + InspectLoaderSubclass=SPLIT_IL) class InspectLoaderGetCodeTests: @@ -495,11 +503,10 @@ class InspectLoaderGetCodeTests: loader.get_code('blah') -class Frozen_ILGetCodeTests(InspectLoaderGetCodeTests, unittest.TestCase): - InspectLoaderSubclass = Frozen_IL - -class Source_ILGetCodeTests(InspectLoaderGetCodeTests, unittest.TestCase): - InspectLoaderSubclass = Source_IL +(Frozen_ILGetCodeTests, + Source_ILGetCodeTests + ) = test_util.test_both(InspectLoaderGetCodeTests, + InspectLoaderSubclass=SPLIT_IL) class InspectLoaderLoadModuleTests: @@ -543,11 +550,10 @@ class InspectLoaderLoadModuleTests: self.assertEqual(module, sys.modules[self.module_name]) -class Frozen_ILLoadModuleTests(InspectLoaderLoadModuleTests, unittest.TestCase): - InspectLoaderSubclass = Frozen_IL - -class Source_ILLoadModuleTests(InspectLoaderLoadModuleTests, unittest.TestCase): - InspectLoaderSubclass = Source_IL +(Frozen_ILLoadModuleTests, + Source_ILLoadModuleTests + ) = test_util.test_both(InspectLoaderLoadModuleTests, + InspectLoaderSubclass=SPLIT_IL) ##### ExecutionLoader concrete methods ######################################### @@ -608,15 +614,14 @@ class ExecutionLoaderGetCodeTests: self.assertEqual(module.attr, 42) -class Frozen_ELGetCodeTests(ExecutionLoaderGetCodeTests, unittest.TestCase): - ExecutionLoaderSubclass = Frozen_EL - -class Source_ELGetCodeTests(ExecutionLoaderGetCodeTests, unittest.TestCase): - ExecutionLoaderSubclass = Source_EL +(Frozen_ELGetCodeTests, + Source_ELGetCodeTests + ) = test_util.test_both(ExecutionLoaderGetCodeTests, + ExecutionLoaderSubclass=SPLIT_EL) ##### SourceLoader concrete methods ############################################ -class SourceLoader: +class SourceOnlyLoader: # Globals that should be defined for all modules. source = (b"_ = '::'.join([__name__, __file__, __cached__, __package__, " @@ -637,10 +642,10 @@ class SourceLoader: return '<module>' -Frozen_SourceOnlyL, Source_SourceOnlyL = make_abc_subclasses(SourceLoader) +SPLIT_SOL = make_abc_subclasses(SourceOnlyLoader, 'SourceLoader') -class SourceLoader(SourceLoader): +class SourceLoader(SourceOnlyLoader): source_mtime = 1 @@ -677,11 +682,7 @@ class SourceLoader(SourceLoader): return path == self.bytecode_path -Frozen_SL, Source_SL = make_abc_subclasses(SourceLoader) -Frozen_SL.util = frozen_util -Source_SL.util = source_util -Frozen_SL.init = frozen_init -Source_SL.init = source_init +SPLIT_SL = make_abc_subclasses(SourceLoader, util=util, init=init) class SourceLoaderTestHarness: @@ -765,7 +766,7 @@ class SourceOnlyLoaderTests(SourceLoaderTestHarness): # Loading a module should set __name__, __loader__, __package__, # __path__ (for packages), __file__, and __cached__. # The module should also be put into sys.modules. - with util.uncache(self.name): + with test_util.uncache(self.name): with warnings.catch_warnings(): warnings.simplefilter('ignore', DeprecationWarning) module = self.loader.load_module(self.name) @@ -778,7 +779,7 @@ class SourceOnlyLoaderTests(SourceLoaderTestHarness): # is a package. # Testing the values for a package are covered by test_load_module. self.setUp(is_package=False) - with util.uncache(self.name): + with test_util.uncache(self.name): with warnings.catch_warnings(): warnings.simplefilter('ignore', DeprecationWarning) module = self.loader.load_module(self.name) @@ -798,13 +799,10 @@ class SourceOnlyLoaderTests(SourceLoaderTestHarness): self.assertEqual(returned_source, source) -class Frozen_SourceOnlyLTests(SourceOnlyLoaderTests, unittest.TestCase): - loader_mock = Frozen_SourceOnlyL - util = frozen_util - -class Source_SourceOnlyLTests(SourceOnlyLoaderTests, unittest.TestCase): - loader_mock = Source_SourceOnlyL - util = source_util +(Frozen_SourceOnlyLoaderTests, + Source_SourceOnlyLoaderTests + ) = test_util.test_both(SourceOnlyLoaderTests, util=util, + loader_mock=SPLIT_SOL) @unittest.skipIf(sys.dont_write_bytecode, "sys.dont_write_bytecode is true") @@ -896,15 +894,10 @@ class SourceLoaderBytecodeTests(SourceLoaderTestHarness): self.verify_code(code_object) -class Frozen_SLBytecodeTests(SourceLoaderBytecodeTests, unittest.TestCase): - loader_mock = Frozen_SL - init = frozen_init - util = frozen_util - -class SourceSLBytecodeTests(SourceLoaderBytecodeTests, unittest.TestCase): - loader_mock = Source_SL - init = source_init - util = source_util +(Frozen_SLBytecodeTests, + SourceSLBytecodeTests + ) = test_util.test_both(SourceLoaderBytecodeTests, init=init, util=util, + loader_mock=SPLIT_SL) class SourceLoaderGetSourceTests: @@ -940,11 +933,10 @@ class SourceLoaderGetSourceTests: self.assertEqual(mock.get_source(name), expect) -class Frozen_SourceOnlyLGetSourceTests(SourceLoaderGetSourceTests, unittest.TestCase): - SourceOnlyLoaderMock = Frozen_SourceOnlyL - -class Source_SourceOnlyLGetSourceTests(SourceLoaderGetSourceTests, unittest.TestCase): - SourceOnlyLoaderMock = Source_SourceOnlyL +(Frozen_SourceOnlyLoaderGetSourceTests, + Source_SourceOnlyLoaderGetSourceTests + ) = test_util.test_both(SourceLoaderGetSourceTests, + SourceOnlyLoaderMock=SPLIT_SOL) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/test_api.py b/Lib/test/test_importlib/test_api.py index 2a2d42b..6bc3c56 100644 --- a/Lib/test/test_importlib/test_api.py +++ b/Lib/test/test_importlib/test_api.py @@ -1,8 +1,8 @@ -from . import util +from . import util as test_util -frozen_init, source_init = util.import_importlib('importlib') -frozen_util, source_util = util.import_importlib('importlib.util') -frozen_machinery, source_machinery = util.import_importlib('importlib.machinery') +init = test_util.import_importlib('importlib') +util = test_util.import_importlib('importlib.util') +machinery = test_util.import_importlib('importlib.machinery') import os.path import sys @@ -18,8 +18,8 @@ class ImportModuleTests: def test_module_import(self): # Test importing a top-level module. - with util.mock_modules('top_level') as mock: - with util.import_state(meta_path=[mock]): + with test_util.mock_modules('top_level') as mock: + with test_util.import_state(meta_path=[mock]): module = self.init.import_module('top_level') self.assertEqual(module.__name__, 'top_level') @@ -28,8 +28,8 @@ class ImportModuleTests: pkg_name = 'pkg' pkg_long_name = '{0}.__init__'.format(pkg_name) name = '{0}.mod'.format(pkg_name) - with util.mock_modules(pkg_long_name, name) as mock: - with util.import_state(meta_path=[mock]): + with test_util.mock_modules(pkg_long_name, name) as mock: + with test_util.import_state(meta_path=[mock]): module = self.init.import_module(name) self.assertEqual(module.__name__, name) @@ -40,16 +40,16 @@ class ImportModuleTests: module_name = 'mod' absolute_name = '{0}.{1}'.format(pkg_name, module_name) relative_name = '.{0}'.format(module_name) - with util.mock_modules(pkg_long_name, absolute_name) as mock: - with util.import_state(meta_path=[mock]): + with test_util.mock_modules(pkg_long_name, absolute_name) as mock: + with test_util.import_state(meta_path=[mock]): self.init.import_module(pkg_name) module = self.init.import_module(relative_name, pkg_name) self.assertEqual(module.__name__, absolute_name) def test_deep_relative_package_import(self): modules = ['a.__init__', 'a.b.__init__', 'a.c'] - with util.mock_modules(*modules) as mock: - with util.import_state(meta_path=[mock]): + with test_util.mock_modules(*modules) as mock: + with test_util.import_state(meta_path=[mock]): self.init.import_module('a') self.init.import_module('a.b') module = self.init.import_module('..c', 'a.b') @@ -61,8 +61,8 @@ class ImportModuleTests: pkg_name = 'pkg' pkg_long_name = '{0}.__init__'.format(pkg_name) name = '{0}.mod'.format(pkg_name) - with util.mock_modules(pkg_long_name, name) as mock: - with util.import_state(meta_path=[mock]): + with test_util.mock_modules(pkg_long_name, name) as mock: + with test_util.import_state(meta_path=[mock]): self.init.import_module(pkg_name) module = self.init.import_module(name, pkg_name) self.assertEqual(module.__name__, name) @@ -86,16 +86,15 @@ class ImportModuleTests: b_load_count += 1 code = {'a': load_a, 'a.b': load_b} modules = ['a.__init__', 'a.b'] - with util.mock_modules(*modules, module_code=code) as mock: - with util.import_state(meta_path=[mock]): + with test_util.mock_modules(*modules, module_code=code) as mock: + with test_util.import_state(meta_path=[mock]): self.init.import_module('a.b') self.assertEqual(b_load_count, 1) -class Frozen_ImportModuleTests(ImportModuleTests, unittest.TestCase): - init = frozen_init -class Source_ImportModuleTests(ImportModuleTests, unittest.TestCase): - init = source_init +(Frozen_ImportModuleTests, + Source_ImportModuleTests + ) = test_util.test_both(ImportModuleTests, init=init) class FindLoaderTests: @@ -107,7 +106,7 @@ class FindLoaderTests: def test_sys_modules(self): # If a module with __loader__ is in sys.modules, then return it. name = 'some_mod' - with util.uncache(name): + with test_util.uncache(name): module = types.ModuleType(name) loader = 'a loader!' module.__loader__ = loader @@ -120,7 +119,7 @@ class FindLoaderTests: def test_sys_modules_loader_is_None(self): # If sys.modules[name].__loader__ is None, raise ValueError. name = 'some_mod' - with util.uncache(name): + with test_util.uncache(name): module = types.ModuleType(name) module.__loader__ = None sys.modules[name] = module @@ -133,7 +132,7 @@ class FindLoaderTests: # Should raise ValueError # Issue #17099 name = 'some_mod' - with util.uncache(name): + with test_util.uncache(name): module = types.ModuleType(name) try: del module.__loader__ @@ -148,8 +147,8 @@ class FindLoaderTests: def test_success(self): # Return the loader found on sys.meta_path. name = 'some_mod' - with util.uncache(name): - with util.import_state(meta_path=[self.FakeMetaFinder]): + with test_util.uncache(name): + with test_util.import_state(meta_path=[self.FakeMetaFinder]): with warnings.catch_warnings(): warnings.simplefilter('ignore', DeprecationWarning) self.assertEqual((name, None), self.init.find_loader(name)) @@ -158,8 +157,8 @@ class FindLoaderTests: # Searching on a path should work. name = 'some_mod' path = 'path to some place' - with util.uncache(name): - with util.import_state(meta_path=[self.FakeMetaFinder]): + with test_util.uncache(name): + with test_util.import_state(meta_path=[self.FakeMetaFinder]): with warnings.catch_warnings(): warnings.simplefilter('ignore', DeprecationWarning) self.assertEqual((name, path), @@ -171,11 +170,10 @@ class FindLoaderTests: warnings.simplefilter('ignore', DeprecationWarning) self.assertIsNone(self.init.find_loader('nevergoingtofindthismodule')) -class Frozen_FindLoaderTests(FindLoaderTests, unittest.TestCase): - init = frozen_init -class Source_FindLoaderTests(FindLoaderTests, unittest.TestCase): - init = source_init +(Frozen_FindLoaderTests, + Source_FindLoaderTests + ) = test_util.test_both(FindLoaderTests, init=init) class ReloadTests: @@ -195,10 +193,10 @@ class ReloadTests: module = type(sys)('top_level') module.spam = 3 sys.modules['top_level'] = module - mock = util.mock_modules('top_level', - module_code={'top_level': code}) + mock = test_util.mock_modules('top_level', + module_code={'top_level': code}) with mock: - with util.import_state(meta_path=[mock]): + with test_util.import_state(meta_path=[mock]): module = self.init.import_module('top_level') reloaded = self.init.reload(module) actual = sys.modules['top_level'] @@ -230,7 +228,7 @@ class ReloadTests: def test_reload_location_changed(self): name = 'spam' with support.temp_cwd(None) as cwd: - with util.uncache('spam'): + with test_util.uncache('spam'): with support.DirsOnSysPath(cwd): # Start as a plain module. self.init.invalidate_caches() @@ -281,7 +279,7 @@ class ReloadTests: def test_reload_namespace_changed(self): name = 'spam' with support.temp_cwd(None) as cwd: - with util.uncache('spam'): + with test_util.uncache('spam'): with support.DirsOnSysPath(cwd): # Start as a namespace package. self.init.invalidate_caches() @@ -338,20 +336,16 @@ class ReloadTests: # See #19851. name = 'spam' subname = 'ham' - with util.temp_module(name, pkg=True) as pkg_dir: - fullname, _ = util.submodule(name, subname, pkg_dir) + with test_util.temp_module(name, pkg=True) as pkg_dir: + fullname, _ = test_util.submodule(name, subname, pkg_dir) ham = self.init.import_module(fullname) reloaded = self.init.reload(ham) self.assertIs(reloaded, ham) -class Frozen_ReloadTests(ReloadTests, unittest.TestCase): - init = frozen_init - util = frozen_util - -class Source_ReloadTests(ReloadTests, unittest.TestCase): - init = source_init - util = source_util +(Frozen_ReloadTests, + Source_ReloadTests + ) = test_util.test_both(ReloadTests, init=init, util=util) class InvalidateCacheTests: @@ -384,11 +378,10 @@ class InvalidateCacheTests: self.addCleanup(lambda: sys.path_importer_cache.__delitem__(key)) self.init.invalidate_caches() # Shouldn't trigger an exception. -class Frozen_InvalidateCacheTests(InvalidateCacheTests, unittest.TestCase): - init = frozen_init -class Source_InvalidateCacheTests(InvalidateCacheTests, unittest.TestCase): - init = source_init +(Frozen_InvalidateCacheTests, + Source_InvalidateCacheTests + ) = test_util.test_both(InvalidateCacheTests, init=init) class FrozenImportlibTests(unittest.TestCase): @@ -398,6 +391,7 @@ class FrozenImportlibTests(unittest.TestCase): # Can't do an isinstance() check since separate copies of importlib # may have been used for import, so just check the name is not for the # frozen loader. + source_init = init['Source'] self.assertNotEqual(source_init.__loader__.__class__.__name__, 'FrozenImporter') @@ -426,11 +420,10 @@ class StartupTests: elif self.machinery.FrozenImporter.find_module(name): self.assertIsNot(module.__spec__, None) -class Frozen_StartupTests(StartupTests, unittest.TestCase): - machinery = frozen_machinery -class Source_StartupTests(StartupTests, unittest.TestCase): - machinery = source_machinery +(Frozen_StartupTests, + Source_StartupTests + ) = test_util.test_both(StartupTests, machinery=machinery) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/test_lazy.py b/Lib/test/test_importlib/test_lazy.py new file mode 100644 index 0000000..2e191bb --- /dev/null +++ b/Lib/test/test_importlib/test_lazy.py @@ -0,0 +1,132 @@ +import importlib +from importlib import abc +from importlib import util +import unittest + +from . import util as test_util + + +class CollectInit: + + def __init__(self, *args, **kwargs): + self.args = args + self.kwargs = kwargs + + def exec_module(self, module): + return self + + +class LazyLoaderFactoryTests(unittest.TestCase): + + def test_init(self): + factory = util.LazyLoader.factory(CollectInit) + # E.g. what importlib.machinery.FileFinder instantiates loaders with + # plus keyword arguments. + lazy_loader = factory('module name', 'module path', kw='kw') + loader = lazy_loader.loader + self.assertEqual(('module name', 'module path'), loader.args) + self.assertEqual({'kw': 'kw'}, loader.kwargs) + + def test_validation(self): + # No exec_module(), no lazy loading. + with self.assertRaises(TypeError): + util.LazyLoader.factory(object) + + +class TestingImporter(abc.MetaPathFinder, abc.Loader): + + module_name = 'lazy_loader_test' + mutated_name = 'changed' + loaded = None + source_code = 'attr = 42; __name__ = {!r}'.format(mutated_name) + + def find_spec(self, name, path, target=None): + if name != self.module_name: + return None + return util.spec_from_loader(name, util.LazyLoader(self)) + + def exec_module(self, module): + exec(self.source_code, module.__dict__) + self.loaded = module + + +class LazyLoaderTests(unittest.TestCase): + + def test_init(self): + with self.assertRaises(TypeError): + util.LazyLoader(object) + + def new_module(self, source_code=None): + loader = TestingImporter() + if source_code is not None: + loader.source_code = source_code + spec = util.spec_from_loader(TestingImporter.module_name, + util.LazyLoader(loader)) + module = spec.loader.create_module(spec) + module.__spec__ = spec + module.__loader__ = spec.loader + spec.loader.exec_module(module) + # Module is now lazy. + self.assertIsNone(loader.loaded) + return module + + def test_e2e(self): + # End-to-end test to verify the load is in fact lazy. + importer = TestingImporter() + assert importer.loaded is None + with test_util.uncache(importer.module_name): + with test_util.import_state(meta_path=[importer]): + module = importlib.import_module(importer.module_name) + self.assertIsNone(importer.loaded) + # Trigger load. + self.assertEqual(module.__loader__, importer) + self.assertIsNotNone(importer.loaded) + self.assertEqual(module, importer.loaded) + + def test_attr_unchanged(self): + # An attribute only mutated as a side-effect of import should not be + # changed needlessly. + module = self.new_module() + self.assertEqual(TestingImporter.mutated_name, module.__name__) + + def test_new_attr(self): + # A new attribute should persist. + module = self.new_module() + module.new_attr = 42 + self.assertEqual(42, module.new_attr) + + def test_mutated_preexisting_attr(self): + # Changing an attribute that already existed on the module -- + # e.g. __name__ -- should persist. + module = self.new_module() + module.__name__ = 'bogus' + self.assertEqual('bogus', module.__name__) + + def test_mutated_attr(self): + # Changing an attribute that comes into existence after an import + # should persist. + module = self.new_module() + module.attr = 6 + self.assertEqual(6, module.attr) + + def test_delete_eventual_attr(self): + # Deleting an attribute should stay deleted. + module = self.new_module() + del module.attr + self.assertFalse(hasattr(module, 'attr')) + + def test_delete_preexisting_attr(self): + module = self.new_module() + del module.__name__ + self.assertFalse(hasattr(module, '__name__')) + + def test_module_substitution_error(self): + source_code = 'import sys; sys.modules[__name__] = 42' + module = self.new_module(source_code) + with test_util.uncache(TestingImporter.module_name): + with self.assertRaises(ValueError): + module.__name__ + + +if __name__ == '__main__': + unittest.main() diff --git a/Lib/test/test_importlib/test_locks.py b/Lib/test/test_importlib/test_locks.py index dc97ba1..df0af12 100644 --- a/Lib/test/test_importlib/test_locks.py +++ b/Lib/test/test_importlib/test_locks.py @@ -1,7 +1,6 @@ -from . import util -frozen_init, source_init = util.import_importlib('importlib') -frozen_bootstrap = frozen_init._bootstrap -source_bootstrap = source_init._bootstrap +from . import util as test_util + +init = test_util.import_importlib('importlib') import sys import time @@ -32,14 +31,20 @@ if threading is not None: test_timeout = None # _release_save() unsupported test_release_save_unacquired = None + # lock status in repr unsupported + test_repr = None + test_locked_repr = None - class Frozen_ModuleLockAsRLockTests(ModuleLockAsRLockTests, lock_tests.RLockTests): - LockType = frozen_bootstrap._ModuleLock - - class Source_ModuleLockAsRLockTests(ModuleLockAsRLockTests, lock_tests.RLockTests): - LockType = source_bootstrap._ModuleLock + LOCK_TYPES = {kind: splitinit._bootstrap._ModuleLock + for kind, splitinit in init.items()} + (Frozen_ModuleLockAsRLockTests, + Source_ModuleLockAsRLockTests + ) = test_util.test_both(ModuleLockAsRLockTests, lock_tests.RLockTests, + LockType=LOCK_TYPES) else: + LOCK_TYPES = {} + class Frozen_ModuleLockAsRLockTests(unittest.TestCase): pass @@ -47,78 +52,94 @@ else: pass -class DeadlockAvoidanceTests: - - def setUp(self): - try: - self.old_switchinterval = sys.getswitchinterval() - sys.setswitchinterval(0.000001) - except AttributeError: - self.old_switchinterval = None - - def tearDown(self): - if self.old_switchinterval is not None: - sys.setswitchinterval(self.old_switchinterval) - - def run_deadlock_avoidance_test(self, create_deadlock): - NLOCKS = 10 - locks = [self.LockType(str(i)) for i in range(NLOCKS)] - pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)] - if create_deadlock: - NTHREADS = NLOCKS - else: - NTHREADS = NLOCKS - 1 - barrier = threading.Barrier(NTHREADS) - results = [] - def _acquire(lock): - """Try to acquire the lock. Return True on success, False on deadlock.""" +if threading is not None: + class DeadlockAvoidanceTests: + + def setUp(self): try: - lock.acquire() - except self.DeadlockError: - return False + self.old_switchinterval = sys.getswitchinterval() + sys.setswitchinterval(0.000001) + except AttributeError: + self.old_switchinterval = None + + def tearDown(self): + if self.old_switchinterval is not None: + sys.setswitchinterval(self.old_switchinterval) + + def run_deadlock_avoidance_test(self, create_deadlock): + NLOCKS = 10 + locks = [self.LockType(str(i)) for i in range(NLOCKS)] + pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)] + if create_deadlock: + NTHREADS = NLOCKS else: - return True - def f(): - a, b = pairs.pop() - ra = _acquire(a) - barrier.wait() - rb = _acquire(b) - results.append((ra, rb)) - if rb: - b.release() - if ra: - a.release() - lock_tests.Bunch(f, NTHREADS).wait_for_finished() - self.assertEqual(len(results), NTHREADS) - return results - - def test_deadlock(self): - results = self.run_deadlock_avoidance_test(True) - # At least one of the threads detected a potential deadlock on its - # second acquire() call. It may be several of them, because the - # deadlock avoidance mechanism is conservative. - nb_deadlocks = results.count((True, False)) - self.assertGreaterEqual(nb_deadlocks, 1) - self.assertEqual(results.count((True, True)), len(results) - nb_deadlocks) - - def test_no_deadlock(self): - results = self.run_deadlock_avoidance_test(False) - self.assertEqual(results.count((True, False)), 0) - self.assertEqual(results.count((True, True)), len(results)) - -@unittest.skipUnless(threading, "threads needed for this test") -class Frozen_DeadlockAvoidanceTests(DeadlockAvoidanceTests, unittest.TestCase): - LockType = frozen_bootstrap._ModuleLock - DeadlockError = frozen_bootstrap._DeadlockError - -@unittest.skipUnless(threading, "threads needed for this test") -class Source_DeadlockAvoidanceTests(DeadlockAvoidanceTests, unittest.TestCase): - LockType = source_bootstrap._ModuleLock - DeadlockError = source_bootstrap._DeadlockError + NTHREADS = NLOCKS - 1 + barrier = threading.Barrier(NTHREADS) + results = [] + + def _acquire(lock): + """Try to acquire the lock. Return True on success, + False on deadlock.""" + try: + lock.acquire() + except self.DeadlockError: + return False + else: + return True + + def f(): + a, b = pairs.pop() + ra = _acquire(a) + barrier.wait() + rb = _acquire(b) + results.append((ra, rb)) + if rb: + b.release() + if ra: + a.release() + lock_tests.Bunch(f, NTHREADS).wait_for_finished() + self.assertEqual(len(results), NTHREADS) + return results + + def test_deadlock(self): + results = self.run_deadlock_avoidance_test(True) + # At least one of the threads detected a potential deadlock on its + # second acquire() call. It may be several of them, because the + # deadlock avoidance mechanism is conservative. + nb_deadlocks = results.count((True, False)) + self.assertGreaterEqual(nb_deadlocks, 1) + self.assertEqual(results.count((True, True)), len(results) - nb_deadlocks) + + def test_no_deadlock(self): + results = self.run_deadlock_avoidance_test(False) + self.assertEqual(results.count((True, False)), 0) + self.assertEqual(results.count((True, True)), len(results)) + + + DEADLOCK_ERRORS = {kind: splitinit._bootstrap._DeadlockError + for kind, splitinit in init.items()} + + (Frozen_DeadlockAvoidanceTests, + Source_DeadlockAvoidanceTests + ) = test_util.test_both(DeadlockAvoidanceTests, + LockType=LOCK_TYPES, + DeadlockError=DEADLOCK_ERRORS) +else: + DEADLOCK_ERRORS = {} + + class Frozen_DeadlockAvoidanceTests(unittest.TestCase): + pass + + class Source_DeadlockAvoidanceTests(unittest.TestCase): + pass class LifetimeTests: + @property + def bootstrap(self): + return self.init._bootstrap + def test_lock_lifetime(self): name = "xyzzy" self.assertNotIn(name, self.bootstrap._module_locks) @@ -135,11 +156,10 @@ class LifetimeTests: self.assertEqual(0, len(self.bootstrap._module_locks), self.bootstrap._module_locks) -class Frozen_LifetimeTests(LifetimeTests, unittest.TestCase): - bootstrap = frozen_bootstrap -class Source_LifetimeTests(LifetimeTests, unittest.TestCase): - bootstrap = source_bootstrap +(Frozen_LifetimeTests, + Source_LifetimeTests + ) = test_util.test_both(LifetimeTests, init=init) @support.reap_threads diff --git a/Lib/test/test_importlib/test_spec.py b/Lib/test/test_importlib/test_spec.py index 71541f6..418b4c0 100644 --- a/Lib/test/test_importlib/test_spec.py +++ b/Lib/test/test_importlib/test_spec.py @@ -1,10 +1,8 @@ -from . import util +from . import util as test_util -frozen_init, source_init = util.import_importlib('importlib') -frozen_bootstrap = frozen_init._bootstrap -source_bootstrap = source_init._bootstrap -frozen_machinery, source_machinery = util.import_importlib('importlib.machinery') -frozen_util, source_util = util.import_importlib('importlib.util') +init = test_util.import_importlib('importlib') +machinery = test_util.import_importlib('importlib.machinery') +util = test_util.import_importlib('importlib.util') import os.path from test.support import CleanImport @@ -52,6 +50,8 @@ class LegacyLoader(TestLoader): with warnings.catch_warnings(): warnings.simplefilter("ignore", DeprecationWarning) + frozen_util = util['Frozen'] + @frozen_util.module_for_loader def load_module(self, module): module.ham = self.HAM @@ -221,18 +221,17 @@ class ModuleSpecTests: self.assertEqual(self.loc_spec.cached, 'spam.pyc') -class Frozen_ModuleSpecTests(ModuleSpecTests, unittest.TestCase): - util = frozen_util - machinery = frozen_machinery - - -class Source_ModuleSpecTests(ModuleSpecTests, unittest.TestCase): - util = source_util - machinery = source_machinery +(Frozen_ModuleSpecTests, + Source_ModuleSpecTests + ) = test_util.test_both(ModuleSpecTests, util=util, machinery=machinery) class ModuleSpecMethodsTests: + @property + def bootstrap(self): + return self.init._bootstrap + def setUp(self): self.name = 'spam' self.path = 'spam.py' @@ -243,152 +242,14 @@ class ModuleSpecMethodsTests: origin=self.path) self.loc_spec._set_fileattr = True - # init_module_attrs - - def test_init_module_attrs(self): - module = type(sys)(self.name) - spec = self.machinery.ModuleSpec(self.name, self.loader) - self.bootstrap._SpecMethods(spec).init_module_attrs(module) - - self.assertEqual(module.__name__, spec.name) - self.assertIs(module.__loader__, spec.loader) - self.assertEqual(module.__package__, spec.parent) - self.assertIs(module.__spec__, spec) - self.assertFalse(hasattr(module, '__path__')) - self.assertFalse(hasattr(module, '__file__')) - self.assertFalse(hasattr(module, '__cached__')) - - def test_init_module_attrs_package(self): - module = type(sys)(self.name) - spec = self.machinery.ModuleSpec(self.name, self.loader) - spec.submodule_search_locations = ['spam', 'ham'] - self.bootstrap._SpecMethods(spec).init_module_attrs(module) - - self.assertEqual(module.__name__, spec.name) - self.assertIs(module.__loader__, spec.loader) - self.assertEqual(module.__package__, spec.parent) - self.assertIs(module.__spec__, spec) - self.assertIs(module.__path__, spec.submodule_search_locations) - self.assertFalse(hasattr(module, '__file__')) - self.assertFalse(hasattr(module, '__cached__')) - - def test_init_module_attrs_location(self): - module = type(sys)(self.name) - spec = self.loc_spec - self.bootstrap._SpecMethods(spec).init_module_attrs(module) - - self.assertEqual(module.__name__, spec.name) - self.assertIs(module.__loader__, spec.loader) - self.assertEqual(module.__package__, spec.parent) - self.assertIs(module.__spec__, spec) - self.assertFalse(hasattr(module, '__path__')) - self.assertEqual(module.__file__, spec.origin) - self.assertEqual(module.__cached__, - self.util.cache_from_source(spec.origin)) - - def test_init_module_attrs_different_name(self): - module = type(sys)('eggs') - spec = self.machinery.ModuleSpec(self.name, self.loader) - self.bootstrap._SpecMethods(spec).init_module_attrs(module) - - self.assertEqual(module.__name__, spec.name) - - def test_init_module_attrs_different_spec(self): - module = type(sys)(self.name) - module.__spec__ = self.machinery.ModuleSpec('eggs', object()) - spec = self.machinery.ModuleSpec(self.name, self.loader) - self.bootstrap._SpecMethods(spec).init_module_attrs(module) - - self.assertEqual(module.__name__, spec.name) - self.assertIs(module.__loader__, spec.loader) - self.assertEqual(module.__package__, spec.parent) - self.assertIs(module.__spec__, spec) - - def test_init_module_attrs_already_set(self): - module = type(sys)('ham.eggs') - module.__loader__ = object() - module.__package__ = 'ham' - module.__path__ = ['eggs'] - module.__file__ = 'ham/eggs/__init__.py' - module.__cached__ = self.util.cache_from_source(module.__file__) - original = vars(module).copy() - spec = self.loc_spec - spec.submodule_search_locations = [''] - self.bootstrap._SpecMethods(spec).init_module_attrs(module) - - self.assertIs(module.__loader__, original['__loader__']) - self.assertEqual(module.__package__, original['__package__']) - self.assertIs(module.__path__, original['__path__']) - self.assertEqual(module.__file__, original['__file__']) - self.assertEqual(module.__cached__, original['__cached__']) - - def test_init_module_attrs_immutable(self): - module = object() - spec = self.loc_spec - spec.submodule_search_locations = [''] - self.bootstrap._SpecMethods(spec).init_module_attrs(module) - - self.assertFalse(hasattr(module, '__name__')) - self.assertFalse(hasattr(module, '__loader__')) - self.assertFalse(hasattr(module, '__package__')) - self.assertFalse(hasattr(module, '__spec__')) - self.assertFalse(hasattr(module, '__path__')) - self.assertFalse(hasattr(module, '__file__')) - self.assertFalse(hasattr(module, '__cached__')) - - # create() - - def test_create(self): - created = self.bootstrap._SpecMethods(self.spec).create() - - self.assertEqual(created.__name__, self.spec.name) - self.assertIs(created.__loader__, self.spec.loader) - self.assertEqual(created.__package__, self.spec.parent) - self.assertIs(created.__spec__, self.spec) - self.assertFalse(hasattr(created, '__path__')) - self.assertFalse(hasattr(created, '__file__')) - self.assertFalse(hasattr(created, '__cached__')) - - def test_create_from_loader(self): - module = type(sys.implementation)() - class CreatingLoader(TestLoader): - def create_module(self, spec): - return module - self.spec.loader = CreatingLoader() - created = self.bootstrap._SpecMethods(self.spec).create() - - self.assertIs(created, module) - self.assertEqual(created.__name__, self.spec.name) - self.assertIs(created.__loader__, self.spec.loader) - self.assertEqual(created.__package__, self.spec.parent) - self.assertIs(created.__spec__, self.spec) - self.assertFalse(hasattr(created, '__path__')) - self.assertFalse(hasattr(created, '__file__')) - self.assertFalse(hasattr(created, '__cached__')) - - def test_create_from_loader_not_handled(self): - class CreatingLoader(TestLoader): - def create_module(self, spec): - return None - self.spec.loader = CreatingLoader() - created = self.bootstrap._SpecMethods(self.spec).create() - - self.assertEqual(created.__name__, self.spec.name) - self.assertIs(created.__loader__, self.spec.loader) - self.assertEqual(created.__package__, self.spec.parent) - self.assertIs(created.__spec__, self.spec) - self.assertFalse(hasattr(created, '__path__')) - self.assertFalse(hasattr(created, '__file__')) - self.assertFalse(hasattr(created, '__cached__')) - # exec() def test_exec(self): self.spec.loader = NewLoader() - module = self.bootstrap._SpecMethods(self.spec).create() + module = self.util.module_from_spec(self.spec) sys.modules[self.name] = module self.assertFalse(hasattr(module, 'eggs')) - self.bootstrap._SpecMethods(self.spec).exec(module) + self.bootstrap._exec(self.spec, module) self.assertEqual(module.eggs, 1) @@ -397,7 +258,7 @@ class ModuleSpecMethodsTests: def test_load(self): self.spec.loader = NewLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) installed = sys.modules[self.spec.name] self.assertEqual(loaded.eggs, 1) @@ -410,7 +271,7 @@ class ModuleSpecMethodsTests: sys.modules[module.__name__] = replacement self.spec.loader = ReplacingLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) installed = sys.modules[self.spec.name] self.assertIs(loaded, replacement) @@ -423,7 +284,7 @@ class ModuleSpecMethodsTests: self.spec.loader = FailedLoader() with CleanImport(self.spec.name): with self.assertRaises(RuntimeError): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) self.assertNotIn(self.spec.name, sys.modules) def test_load_failed_removed(self): @@ -434,20 +295,20 @@ class ModuleSpecMethodsTests: self.spec.loader = FailedLoader() with CleanImport(self.spec.name): with self.assertRaises(RuntimeError): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) self.assertNotIn(self.spec.name, sys.modules) def test_load_legacy(self): self.spec.loader = LegacyLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) self.assertEqual(loaded.ham, -1) def test_load_legacy_attributes(self): self.spec.loader = LegacyLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) self.assertIs(loaded.__loader__, self.spec.loader) self.assertEqual(loaded.__package__, self.spec.parent) @@ -461,7 +322,7 @@ class ModuleSpecMethodsTests: return module self.spec.loader = ImmutableLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) self.assertIs(sys.modules[self.spec.name], module) @@ -470,8 +331,8 @@ class ModuleSpecMethodsTests: def test_reload(self): self.spec.loader = NewLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() - reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded) + loaded = self.bootstrap._load(self.spec) + reloaded = self.bootstrap._exec(self.spec, loaded) installed = sys.modules[self.spec.name] self.assertEqual(loaded.eggs, 1) @@ -481,9 +342,9 @@ class ModuleSpecMethodsTests: def test_reload_modified(self): self.spec.loader = NewLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) loaded.eggs = 2 - reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded) + reloaded = self.bootstrap._exec(self.spec, loaded) self.assertEqual(loaded.eggs, 1) self.assertIs(reloaded, loaded) @@ -491,9 +352,9 @@ class ModuleSpecMethodsTests: def test_reload_extra_attributes(self): self.spec.loader = NewLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) loaded.available = False - reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded) + reloaded = self.bootstrap._exec(self.spec, loaded) self.assertFalse(loaded.available) self.assertIs(reloaded, loaded) @@ -501,12 +362,12 @@ class ModuleSpecMethodsTests: def test_reload_init_module_attrs(self): self.spec.loader = NewLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() + loaded = self.bootstrap._load(self.spec) loaded.__name__ = 'ham' del loaded.__loader__ del loaded.__package__ del loaded.__spec__ - self.bootstrap._SpecMethods(self.spec).exec(loaded) + self.bootstrap._exec(self.spec, loaded) self.assertEqual(loaded.__name__, self.spec.name) self.assertIs(loaded.__loader__, self.spec.loader) @@ -519,8 +380,8 @@ class ModuleSpecMethodsTests: def test_reload_legacy(self): self.spec.loader = LegacyLoader() with CleanImport(self.spec.name): - loaded = self.bootstrap._SpecMethods(self.spec).load() - reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded) + loaded = self.bootstrap._load(self.spec) + reloaded = self.bootstrap._exec(self.spec, loaded) installed = sys.modules[self.spec.name] self.assertEqual(loaded.ham, -1) @@ -528,20 +389,18 @@ class ModuleSpecMethodsTests: self.assertIs(installed, loaded) -class Frozen_ModuleSpecMethodsTests(ModuleSpecMethodsTests, unittest.TestCase): - bootstrap = frozen_bootstrap - machinery = frozen_machinery - util = frozen_util - - -class Source_ModuleSpecMethodsTests(ModuleSpecMethodsTests, unittest.TestCase): - bootstrap = source_bootstrap - machinery = source_machinery - util = source_util +(Frozen_ModuleSpecMethodsTests, + Source_ModuleSpecMethodsTests + ) = test_util.test_both(ModuleSpecMethodsTests, init=init, util=util, + machinery=machinery) class ModuleReprTests: + @property + def bootstrap(self): + return self.init._bootstrap + def setUp(self): self.module = type(os)('spam') self.spec = self.machinery.ModuleSpec('spam', TestLoader()) @@ -625,16 +484,10 @@ class ModuleReprTests: self.assertEqual(modrepr, '<module {!r}>'.format('spam')) -class Frozen_ModuleReprTests(ModuleReprTests, unittest.TestCase): - bootstrap = frozen_bootstrap - machinery = frozen_machinery - util = frozen_util - - -class Source_ModuleReprTests(ModuleReprTests, unittest.TestCase): - bootstrap = source_bootstrap - machinery = source_machinery - util = source_util +(Frozen_ModuleReprTests, + Source_ModuleReprTests + ) = test_util.test_both(ModuleReprTests, init=init, util=util, + machinery=machinery) class FactoryTests: @@ -787,13 +640,14 @@ class FactoryTests: # spec_from_file_location() def test_spec_from_file_location_default(self): - if self.machinery is source_machinery: - raise unittest.SkipTest('not sure why this is breaking...') spec = self.util.spec_from_file_location(self.name, self.path) self.assertEqual(spec.name, self.name) + # Need to use a circuitous route to get at importlib.machinery to make + # sure the same class object is used in the isinstance() check as + # would have been used to create the loader. self.assertIsInstance(spec.loader, - self.machinery.SourceFileLoader) + self.util.abc.machinery.SourceFileLoader) self.assertEqual(spec.loader.name, self.name) self.assertEqual(spec.loader.path, self.path) self.assertEqual(spec.origin, self.path) @@ -947,11 +801,10 @@ class FactoryTests: self.assertTrue(spec.has_location) -class Frozen_FactoryTests(FactoryTests, unittest.TestCase): - util = frozen_util - machinery = frozen_machinery +(Frozen_FactoryTests, + Source_FactoryTests + ) = test_util.test_both(FactoryTests, util=util, machinery=machinery) -class Source_FactoryTests(FactoryTests, unittest.TestCase): - util = source_util - machinery = source_machinery +if __name__ == '__main__': + unittest.main() diff --git a/Lib/test/test_importlib/test_util.py b/Lib/test/test_importlib/test_util.py index b2823c6..cd9344c 100644 --- a/Lib/test/test_importlib/test_util.py +++ b/Lib/test/test_importlib/test_util.py @@ -1,8 +1,8 @@ -from importlib import util -from . import util as test_util -frozen_init, source_init = test_util.import_importlib('importlib') -frozen_machinery, source_machinery = test_util.import_importlib('importlib.machinery') -frozen_util, source_util = test_util.import_importlib('importlib.util') +from . import util +abc = util.import_importlib('importlib.abc') +init = util.import_importlib('importlib') +machinery = util.import_importlib('importlib.machinery') +importlib_util = util.import_importlib('importlib.util') import os import sys @@ -32,8 +32,88 @@ class DecodeSourceBytesTests: self.assertEqual(self.util.decode_source(source_bytes), '\n'.join([self.source, self.source])) -Frozen_DecodeSourceBytesTests, Source_DecodeSourceBytesTests = test_util.test_both( - DecodeSourceBytesTests, util=[frozen_util, source_util]) + +(Frozen_DecodeSourceBytesTests, + Source_DecodeSourceBytesTests + ) = util.test_both(DecodeSourceBytesTests, util=importlib_util) + + +class ModuleFromSpecTests: + + def test_no_create_module(self): + class Loader(self.abc.Loader): + pass + spec = self.machinery.ModuleSpec('test', Loader()) + module = self.util.module_from_spec(spec) + self.assertIsInstance(module, types.ModuleType) + self.assertEqual(module.__name__, spec.name) + + def test_create_module_returns_None(self): + class Loader(self.abc.Loader): + def create_module(self, spec): + return None + spec = self.machinery.ModuleSpec('test', Loader()) + module = self.util.module_from_spec(spec) + self.assertIsInstance(module, types.ModuleType) + self.assertEqual(module.__name__, spec.name) + + def test_create_module(self): + name = 'already set' + class CustomModule(types.ModuleType): + pass + class Loader(self.abc.Loader): + def create_module(self, spec): + module = CustomModule(spec.name) + module.__name__ = name + return module + spec = self.machinery.ModuleSpec('test', Loader()) + module = self.util.module_from_spec(spec) + self.assertIsInstance(module, CustomModule) + self.assertEqual(module.__name__, name) + + def test___name__(self): + spec = self.machinery.ModuleSpec('test', object()) + module = self.util.module_from_spec(spec) + self.assertEqual(module.__name__, spec.name) + + def test___spec__(self): + spec = self.machinery.ModuleSpec('test', object()) + module = self.util.module_from_spec(spec) + self.assertEqual(module.__spec__, spec) + + def test___loader__(self): + loader = object() + spec = self.machinery.ModuleSpec('test', loader) + module = self.util.module_from_spec(spec) + self.assertIs(module.__loader__, loader) + + def test___package__(self): + spec = self.machinery.ModuleSpec('test.pkg', object()) + module = self.util.module_from_spec(spec) + self.assertEqual(module.__package__, spec.parent) + + def test___path__(self): + spec = self.machinery.ModuleSpec('test', object(), is_package=True) + module = self.util.module_from_spec(spec) + self.assertEqual(module.__path__, spec.submodule_search_locations) + + def test___file__(self): + spec = self.machinery.ModuleSpec('test', object(), origin='some/path') + spec.has_location = True + module = self.util.module_from_spec(spec) + self.assertEqual(module.__file__, spec.origin) + + def test___cached__(self): + spec = self.machinery.ModuleSpec('test', object()) + spec.cached = 'some/path' + spec.has_location = True + module = self.util.module_from_spec(spec) + self.assertEqual(module.__cached__, spec.cached) + +(Frozen_ModuleFromSpecTests, + Source_ModuleFromSpecTests +) = util.test_both(ModuleFromSpecTests, abc=abc, machinery=machinery, + util=importlib_util) class ModuleForLoaderTests: @@ -70,7 +150,7 @@ class ModuleForLoaderTests: # Test that when no module exists in sys.modules a new module is # created. module_name = 'a.b.c' - with test_util.uncache(module_name): + with util.uncache(module_name): module = self.return_module(module_name) self.assertIn(module_name, sys.modules) self.assertIsInstance(module, types.ModuleType) @@ -88,7 +168,7 @@ class ModuleForLoaderTests: module = types.ModuleType('a.b.c') module.__loader__ = 42 module.__package__ = 42 - with test_util.uncache(name): + with util.uncache(name): sys.modules[name] = module loader = FakeLoader() returned_module = loader.load_module(name) @@ -100,7 +180,7 @@ class ModuleForLoaderTests: # Test that a module is removed from sys.modules if added but an # exception is raised. name = 'a.b.c' - with test_util.uncache(name): + with util.uncache(name): self.raise_exception(name) self.assertNotIn(name, sys.modules) @@ -108,7 +188,7 @@ class ModuleForLoaderTests: # Test that a failure on reload leaves the module in-place. name = 'a.b.c' module = types.ModuleType(name) - with test_util.uncache(name): + with util.uncache(name): sys.modules[name] = module self.raise_exception(name) self.assertIs(module, sys.modules[name]) @@ -127,7 +207,7 @@ class ModuleForLoaderTests: name = 'mod' module = FalseModule(name) - with test_util.uncache(name): + with util.uncache(name): self.assertFalse(module) sys.modules[name] = module given = self.return_module(name) @@ -146,7 +226,7 @@ class ModuleForLoaderTests: return module name = 'pkg.mod' - with test_util.uncache(name): + with util.uncache(name): loader = FakeLoader(False) module = loader.load_module(name) self.assertEqual(module.__name__, name) @@ -154,15 +234,17 @@ class ModuleForLoaderTests: self.assertEqual(module.__package__, 'pkg') name = 'pkg.sub' - with test_util.uncache(name): + with util.uncache(name): loader = FakeLoader(True) module = loader.load_module(name) self.assertEqual(module.__name__, name) self.assertIs(module.__loader__, loader) self.assertEqual(module.__package__, name) -Frozen_ModuleForLoaderTests, Source_ModuleForLoaderTests = test_util.test_both( - ModuleForLoaderTests, util=[frozen_util, source_util]) + +(Frozen_ModuleForLoaderTests, + Source_ModuleForLoaderTests + ) = util.test_both(ModuleForLoaderTests, util=importlib_util) class SetPackageTests: @@ -222,18 +304,25 @@ class SetPackageTests: self.assertEqual(wrapped.__name__, fxn.__name__) self.assertEqual(wrapped.__qualname__, fxn.__qualname__) -Frozen_SetPackageTests, Source_SetPackageTests = test_util.test_both( - SetPackageTests, util=[frozen_util, source_util]) + +(Frozen_SetPackageTests, + Source_SetPackageTests + ) = util.test_both(SetPackageTests, util=importlib_util) class SetLoaderTests: """Tests importlib.util.set_loader().""" - class DummyLoader: - @util.set_loader - def load_module(self, module): - return self.module + @property + def DummyLoader(self): + # Set DummyLoader on the class lazily. + class DummyLoader: + @self.util.set_loader + def load_module(self, module): + return self.module + self.__class__.DummyLoader = DummyLoader + return DummyLoader def test_no_attribute(self): loader = self.DummyLoader() @@ -262,17 +351,10 @@ class SetLoaderTests: warnings.simplefilter('ignore', DeprecationWarning) self.assertEqual(42, loader.load_module('blah').__loader__) -class Frozen_SetLoaderTests(SetLoaderTests, unittest.TestCase): - class DummyLoader: - @frozen_util.set_loader - def load_module(self, module): - return self.module -class Source_SetLoaderTests(SetLoaderTests, unittest.TestCase): - class DummyLoader: - @source_util.set_loader - def load_module(self, module): - return self.module +(Frozen_SetLoaderTests, + Source_SetLoaderTests + ) = util.test_both(SetLoaderTests, util=importlib_util) class ResolveNameTests: @@ -307,9 +389,10 @@ class ResolveNameTests: with self.assertRaises(ValueError): self.util.resolve_name('..bacon', 'spam') -Frozen_ResolveNameTests, Source_ResolveNameTests = test_util.test_both( - ResolveNameTests, - util=[frozen_util, source_util]) + +(Frozen_ResolveNameTests, + Source_ResolveNameTests + ) = util.test_both(ResolveNameTests, util=importlib_util) class FindSpecTests: @@ -320,7 +403,7 @@ class FindSpecTests: def test_sys_modules(self): name = 'some_mod' - with test_util.uncache(name): + with util.uncache(name): module = types.ModuleType(name) loader = 'a loader!' spec = self.machinery.ModuleSpec(name, loader) @@ -332,7 +415,7 @@ class FindSpecTests: def test_sys_modules_without___loader__(self): name = 'some_mod' - with test_util.uncache(name): + with util.uncache(name): module = types.ModuleType(name) del module.__loader__ loader = 'a loader!' @@ -344,7 +427,7 @@ class FindSpecTests: def test_sys_modules_spec_is_None(self): name = 'some_mod' - with test_util.uncache(name): + with util.uncache(name): module = types.ModuleType(name) module.__spec__ = None sys.modules[name] = module @@ -353,7 +436,7 @@ class FindSpecTests: def test_sys_modules_loader_is_None(self): name = 'some_mod' - with test_util.uncache(name): + with util.uncache(name): module = types.ModuleType(name) spec = self.machinery.ModuleSpec(name, None) module.__spec__ = spec @@ -363,7 +446,7 @@ class FindSpecTests: def test_sys_modules_spec_is_not_set(self): name = 'some_mod' - with test_util.uncache(name): + with util.uncache(name): module = types.ModuleType(name) try: del module.__spec__ @@ -375,8 +458,8 @@ class FindSpecTests: def test_success(self): name = 'some_mod' - with test_util.uncache(name): - with test_util.import_state(meta_path=[self.FakeMetaFinder]): + with util.uncache(name): + with util.import_state(meta_path=[self.FakeMetaFinder]): self.assertEqual((name, None, None), self.util.find_spec(name)) @@ -384,8 +467,8 @@ class FindSpecTests: # # Searching on a path should work. # name = 'some_mod' # path = 'path to some place' -# with test_util.uncache(name): -# with test_util.import_state(meta_path=[self.FakeMetaFinder]): +# with util.uncache(name): +# with util.import_state(meta_path=[self.FakeMetaFinder]): # self.assertEqual((name, path, None), # self.util.find_spec(name, path)) @@ -396,8 +479,8 @@ class FindSpecTests: def test_find_submodule(self): name = 'spam' subname = 'ham' - with test_util.temp_module(name, pkg=True) as pkg_dir: - fullname, _ = test_util.submodule(name, subname, pkg_dir) + with util.temp_module(name, pkg=True) as pkg_dir: + fullname, _ = util.submodule(name, subname, pkg_dir) spec = self.util.find_spec(fullname) self.assertIsNot(spec, None) self.assertIn(name, sorted(sys.modules)) @@ -409,9 +492,9 @@ class FindSpecTests: def test_find_submodule_parent_already_imported(self): name = 'spam' subname = 'ham' - with test_util.temp_module(name, pkg=True) as pkg_dir: + with util.temp_module(name, pkg=True) as pkg_dir: self.init.import_module(name) - fullname, _ = test_util.submodule(name, subname, pkg_dir) + fullname, _ = util.submodule(name, subname, pkg_dir) spec = self.util.find_spec(fullname) self.assertIsNot(spec, None) self.assertIn(name, sorted(sys.modules)) @@ -423,8 +506,8 @@ class FindSpecTests: def test_find_relative_module(self): name = 'spam' subname = 'ham' - with test_util.temp_module(name, pkg=True) as pkg_dir: - fullname, _ = test_util.submodule(name, subname, pkg_dir) + with util.temp_module(name, pkg=True) as pkg_dir: + fullname, _ = util.submodule(name, subname, pkg_dir) relname = '.' + subname spec = self.util.find_spec(relname, name) self.assertIsNot(spec, None) @@ -437,8 +520,8 @@ class FindSpecTests: def test_find_relative_module_missing_package(self): name = 'spam' subname = 'ham' - with test_util.temp_module(name, pkg=True) as pkg_dir: - fullname, _ = test_util.submodule(name, subname, pkg_dir) + with util.temp_module(name, pkg=True) as pkg_dir: + fullname, _ = util.submodule(name, subname, pkg_dir) relname = '.' + subname with self.assertRaises(ValueError): self.util.find_spec(relname) @@ -446,15 +529,10 @@ class FindSpecTests: self.assertNotIn(fullname, sorted(sys.modules)) -class Frozen_FindSpecTests(FindSpecTests, unittest.TestCase): - init = frozen_init - machinery = frozen_machinery - util = frozen_util - -class Source_FindSpecTests(FindSpecTests, unittest.TestCase): - init = source_init - machinery = source_machinery - util = source_util +(Frozen_FindSpecTests, + Source_FindSpecTests + ) = util.test_both(FindSpecTests, init=init, util=importlib_util, + machinery=machinery) class MagicNumberTests: @@ -467,8 +545,10 @@ class MagicNumberTests: # The magic number uses \r\n to come out wrong when splitting on lines. self.assertTrue(self.util.MAGIC_NUMBER.endswith(b'\r\n')) -Frozen_MagicNumberTests, Source_MagicNumberTests = test_util.test_both( - MagicNumberTests, util=[frozen_util, source_util]) + +(Frozen_MagicNumberTests, + Source_MagicNumberTests + ) = util.test_both(MagicNumberTests, util=importlib_util) class PEP3147Tests: @@ -583,9 +663,10 @@ class PEP3147Tests: ValueError, self.util.source_from_cache, '/foo/bar/foo.cpython-32.foo.pyc') -Frozen_PEP3147Tests, Source_PEP3147Tests = test_util.test_both( - PEP3147Tests, - util=[frozen_util, source_util]) + +(Frozen_PEP3147Tests, + Source_PEP3147Tests + ) = util.test_both(PEP3147Tests, util=importlib_util) if __name__ == '__main__': diff --git a/Lib/test/test_importlib/test_windows.py b/Lib/test/test_importlib/test_windows.py index 96b4adc..d4c771c 100644 --- a/Lib/test/test_importlib/test_windows.py +++ b/Lib/test/test_importlib/test_windows.py @@ -1,5 +1,5 @@ -from . import util -frozen_machinery, source_machinery = util.import_importlib('importlib.machinery') +from . import util as test_util +machinery = test_util.import_importlib('importlib.machinery') import sys import unittest @@ -19,11 +19,6 @@ class WindowsRegistryFinderTests: self.assertIs(loader, None) -class Frozen_WindowsRegistryFinderTests(WindowsRegistryFinderTests, - unittest.TestCase): - machinery = frozen_machinery - - -class Source_WindowsRegistryFinderTests(WindowsRegistryFinderTests, - unittest.TestCase): - machinery = source_machinery +(Frozen_WindowsRegistryFinderTests, + Source_WindowsRegistryFinderTests + ) = test_util.test_both(WindowsRegistryFinderTests, machinery=machinery) diff --git a/Lib/test/test_importlib/util.py b/Lib/test/test_importlib/util.py index 885cec3..aa4cd7e 100644 --- a/Lib/test/test_importlib/util.py +++ b/Lib/test/test_importlib/util.py @@ -1,31 +1,85 @@ -from contextlib import contextmanager -from importlib import util, invalidate_caches +import builtins +import contextlib +import errno +import functools +import importlib +from importlib import machinery, util, invalidate_caches +import os import os.path from test import support import unittest import sys +import tempfile import types +BUILTINS = types.SimpleNamespace() +BUILTINS.good_name = None +BUILTINS.bad_name = None +if 'errno' in sys.builtin_module_names: + BUILTINS.good_name = 'errno' +if 'importlib' not in sys.builtin_module_names: + BUILTINS.bad_name = 'importlib' + +EXTENSIONS = types.SimpleNamespace() +EXTENSIONS.path = None +EXTENSIONS.ext = None +EXTENSIONS.filename = None +EXTENSIONS.file_path = None +EXTENSIONS.name = '_testcapi' + +def _extension_details(): + global EXTENSIONS + for path in sys.path: + for ext in machinery.EXTENSION_SUFFIXES: + filename = EXTENSIONS.name + ext + file_path = os.path.join(path, filename) + if os.path.exists(file_path): + EXTENSIONS.path = path + EXTENSIONS.ext = ext + EXTENSIONS.filename = filename + EXTENSIONS.file_path = file_path + return + +_extension_details() + + def import_importlib(module_name): """Import a module from importlib both w/ and w/o _frozen_importlib.""" fresh = ('importlib',) if '.' in module_name else () frozen = support.import_fresh_module(module_name) source = support.import_fresh_module(module_name, fresh=fresh, blocked=('_frozen_importlib',)) + return {'Frozen': frozen, 'Source': source} + + +def specialize_class(cls, kind, base=None, **kwargs): + # XXX Support passing in submodule names--load (and cache) them? + # That would clean up the test modules a bit more. + if base is None: + base = unittest.TestCase + elif not isinstance(base, type): + base = base[kind] + name = '{}_{}'.format(kind, cls.__name__) + bases = (cls, base) + specialized = types.new_class(name, bases) + specialized.__module__ = cls.__module__ + specialized._NAME = cls.__name__ + specialized._KIND = kind + for attr, values in kwargs.items(): + value = values[kind] + setattr(specialized, attr, value) + return specialized + + +def split_frozen(cls, base=None, **kwargs): + frozen = specialize_class(cls, 'Frozen', base, **kwargs) + source = specialize_class(cls, 'Source', base, **kwargs) return frozen, source -def test_both(test_class, **kwargs): - frozen_tests = types.new_class('Frozen_'+test_class.__name__, - (test_class, unittest.TestCase)) - source_tests = types.new_class('Source_'+test_class.__name__, - (test_class, unittest.TestCase)) - frozen_tests.__module__ = source_tests.__module__ = test_class.__module__ - for attr, (frozen_value, source_value) in kwargs.items(): - setattr(frozen_tests, attr, frozen_value) - setattr(source_tests, attr, source_value) - return frozen_tests, source_tests +def test_both(test_class, base=None, **kwargs): + return split_frozen(test_class, base, **kwargs) CASE_INSENSITIVE_FS = True @@ -38,6 +92,10 @@ if sys.platform not in ('win32', 'cygwin'): if not os.path.exists(changed_name): CASE_INSENSITIVE_FS = False +source_importlib = import_importlib('importlib')['Source'] +__import__ = {'Frozen': staticmethod(builtins.__import__), + 'Source': staticmethod(source_importlib.__import__)} + def case_insensitive_tests(test): """Class decorator that nullifies tests requiring a case-insensitive @@ -53,7 +111,7 @@ def submodule(parent, name, pkg_dir, content=''): return '{}.{}'.format(parent, name), path -@contextmanager +@contextlib.contextmanager def uncache(*names): """Uncache a module from sys.modules. @@ -79,7 +137,7 @@ def uncache(*names): pass -@contextmanager +@contextlib.contextmanager def temp_module(name, content='', *, pkg=False): conflicts = [n for n in sys.modules if n.partition('.')[0] == name] with support.temp_cwd(None) as cwd: @@ -103,7 +161,7 @@ def temp_module(name, content='', *, pkg=False): yield location -@contextmanager +@contextlib.contextmanager def import_state(**kwargs): """Context manager to manage the various importers and stored state in the sys module. @@ -198,6 +256,7 @@ class mock_modules(_ImporterMock): raise return self.modules[fullname] + class mock_spec(_ImporterMock): """Importer mock using PEP 451 APIs.""" @@ -223,3 +282,99 @@ class mock_spec(_ImporterMock): self.module_code[module.__spec__.name]() except KeyError: pass + + +def writes_bytecode_files(fxn): + """Decorator to protect sys.dont_write_bytecode from mutation and to skip + tests that require it to be set to False.""" + if sys.dont_write_bytecode: + return lambda *args, **kwargs: None + @functools.wraps(fxn) + def wrapper(*args, **kwargs): + original = sys.dont_write_bytecode + sys.dont_write_bytecode = False + try: + to_return = fxn(*args, **kwargs) + finally: + sys.dont_write_bytecode = original + return to_return + return wrapper + + +def ensure_bytecode_path(bytecode_path): + """Ensure that the __pycache__ directory for PEP 3147 pyc file exists. + + :param bytecode_path: File system path to PEP 3147 pyc file. + """ + try: + os.mkdir(os.path.dirname(bytecode_path)) + except OSError as error: + if error.errno != errno.EEXIST: + raise + + +@contextlib.contextmanager +def create_modules(*names): + """Temporarily create each named module with an attribute (named 'attr') + that contains the name passed into the context manager that caused the + creation of the module. + + All files are created in a temporary directory returned by + tempfile.mkdtemp(). This directory is inserted at the beginning of + sys.path. When the context manager exits all created files (source and + bytecode) are explicitly deleted. + + No magic is performed when creating packages! This means that if you create + a module within a package you must also create the package's __init__ as + well. + + """ + source = 'attr = {0!r}' + created_paths = [] + mapping = {} + state_manager = None + uncache_manager = None + try: + temp_dir = tempfile.mkdtemp() + mapping['.root'] = temp_dir + import_names = set() + for name in names: + if not name.endswith('__init__'): + import_name = name + else: + import_name = name[:-len('.__init__')] + import_names.add(import_name) + if import_name in sys.modules: + del sys.modules[import_name] + name_parts = name.split('.') + file_path = temp_dir + for directory in name_parts[:-1]: + file_path = os.path.join(file_path, directory) + if not os.path.exists(file_path): + os.mkdir(file_path) + created_paths.append(file_path) + file_path = os.path.join(file_path, name_parts[-1] + '.py') + with open(file_path, 'w') as file: + file.write(source.format(name)) + created_paths.append(file_path) + mapping[name] = file_path + uncache_manager = uncache(*import_names) + uncache_manager.__enter__() + state_manager = import_state(path=[temp_dir]) + state_manager.__enter__() + yield mapping + finally: + if state_manager is not None: + state_manager.__exit__(None, None, None) + if uncache_manager is not None: + uncache_manager.__exit__(None, None, None) + support.rmtree(temp_dir) + + +def mock_path_hook(*entries, importer): + """A mock sys.path_hooks entry.""" + def hook(entry): + if entry not in entries: + raise ImportError + return importer + return hook diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py index da0572d..63bdb15 100644 --- a/Lib/test/test_inspect.py +++ b/Lib/test/test_inspect.py @@ -8,6 +8,7 @@ import linecache import os from os.path import normcase import _pickle +import pickle import re import shutil import sys @@ -73,6 +74,7 @@ def generator_function_example(self): for i in range(2): yield i + class TestPredicates(IsTestBase): def test_sixteen(self): count = len([x for x in dir(inspect) if x.startswith('is')]) @@ -1611,6 +1613,17 @@ class TestGetGeneratorState(unittest.TestCase): self.assertRaises(TypeError, inspect.getgeneratorlocals, (2,3)) +class MySignature(inspect.Signature): + # Top-level to make it picklable; + # used in test_signature_object_pickle + pass + +class MyParameter(inspect.Parameter): + # Top-level to make it picklable; + # used in test_signature_object_pickle + pass + + class TestSignatureObject(unittest.TestCase): @staticmethod def signature(func): @@ -1668,6 +1681,37 @@ class TestSignatureObject(unittest.TestCase): with self.assertRaisesRegex(ValueError, 'follows default argument'): S((pkd, pk)) + self.assertTrue(repr(sig).startswith('<Signature')) + self.assertTrue('"(po, pk' in repr(sig)) + + def test_signature_object_pickle(self): + def foo(a, b, *, c:1={}, **kw) -> {42:'ham'}: pass + foo_partial = functools.partial(foo, a=1) + + sig = inspect.signature(foo_partial) + + for ver in range(pickle.HIGHEST_PROTOCOL + 1): + with self.subTest(pickle_ver=ver, subclass=False): + sig_pickled = pickle.loads(pickle.dumps(sig, ver)) + self.assertEqual(sig, sig_pickled) + + # Test that basic sub-classing works + sig = inspect.signature(foo) + myparam = MyParameter(name='z', kind=inspect.Parameter.POSITIONAL_ONLY) + myparams = collections.OrderedDict(sig.parameters, a=myparam) + mysig = MySignature().replace(parameters=myparams.values(), + return_annotation=sig.return_annotation) + self.assertTrue(isinstance(mysig, MySignature)) + self.assertTrue(isinstance(mysig.parameters['z'], MyParameter)) + + for ver in range(pickle.HIGHEST_PROTOCOL + 1): + with self.subTest(pickle_ver=ver, subclass=True): + sig_pickled = pickle.loads(pickle.dumps(mysig, ver)) + self.assertEqual(mysig, sig_pickled) + self.assertTrue(isinstance(sig_pickled, MySignature)) + self.assertTrue(isinstance(sig_pickled.parameters['z'], + MyParameter)) + def test_signature_immutability(self): def test(a): pass @@ -2469,11 +2513,29 @@ class TestSignatureObject(unittest.TestCase): def bar(pos, *args, c, b, a=42, **kwargs:int): pass self.assertEqual(inspect.signature(foo), inspect.signature(bar)) - def test_signature_unhashable(self): + def test_signature_hashable(self): + S = inspect.Signature + P = inspect.Parameter + def foo(a): pass - sig = inspect.signature(foo) + foo_sig = inspect.signature(foo) + + manual_sig = S(parameters=[P('a', P.POSITIONAL_OR_KEYWORD)]) + + self.assertEqual(hash(foo_sig), hash(manual_sig)) + self.assertNotEqual(hash(foo_sig), + hash(manual_sig.replace(return_annotation='spam'))) + + def bar(a) -> 1: pass + self.assertNotEqual(hash(foo_sig), hash(inspect.signature(bar))) + + def foo(a={}): pass + with self.assertRaisesRegex(TypeError, 'unhashable type'): + hash(inspect.signature(foo)) + + def foo(a) -> {}: pass with self.assertRaisesRegex(TypeError, 'unhashable type'): - hash(sig) + hash(inspect.signature(foo)) def test_signature_str(self): def foo(a:int=1, *, b, c=None, **kwargs) -> 42: @@ -2547,6 +2609,19 @@ class TestSignatureObject(unittest.TestCase): self.assertEqual(self.signature(Spam.foo), self.signature(Ham.foo)) + def test_signature_from_callable_python_obj(self): + class MySignature(inspect.Signature): pass + def foo(a, *, b:1): pass + foo_sig = MySignature.from_callable(foo) + self.assertTrue(isinstance(foo_sig, MySignature)) + + @unittest.skipIf(MISSING_C_DOCSTRINGS, + "Signature information for builtins requires docstrings") + def test_signature_from_callable_builtin_obj(self): + class MySignature(inspect.Signature): pass + sig = MySignature.from_callable(_pickle.Pickler) + self.assertTrue(isinstance(sig, MySignature)) + class TestParameterObject(unittest.TestCase): def test_signature_parameter_kinds(self): @@ -2592,6 +2667,16 @@ class TestParameterObject(unittest.TestCase): p.replace(kind=inspect.Parameter.VAR_POSITIONAL) self.assertTrue(repr(p).startswith('<Parameter')) + self.assertTrue('"a=42"' in repr(p)) + + def test_signature_parameter_hashable(self): + P = inspect.Parameter + foo = P('foo', kind=P.POSITIONAL_ONLY) + self.assertEqual(hash(foo), hash(P('foo', kind=P.POSITIONAL_ONLY))) + self.assertNotEqual(hash(foo), hash(P('foo', kind=P.POSITIONAL_ONLY, + default=42))) + self.assertNotEqual(hash(foo), + hash(foo.replace(kind=P.VAR_POSITIONAL))) def test_signature_parameter_equality(self): P = inspect.Parameter @@ -2603,13 +2688,6 @@ class TestParameterObject(unittest.TestCase): self.assertEqual(p, P('foo', default=42, kind=inspect.Parameter.KEYWORD_ONLY)) - def test_signature_parameter_unhashable(self): - p = inspect.Parameter('foo', default=42, - kind=inspect.Parameter.KEYWORD_ONLY) - - with self.assertRaisesRegex(TypeError, 'unhashable type'): - hash(p) - def test_signature_parameter_replace(self): p = inspect.Parameter('foo', default=42, kind=inspect.Parameter.KEYWORD_ONLY) @@ -2918,6 +2996,16 @@ class TestBoundArguments(unittest.TestCase): ba4 = inspect.signature(bar).bind(1) self.assertNotEqual(ba, ba4) + def test_signature_bound_arguments_pickle(self): + def foo(a, b, *, c:1={}, **kw) -> {42:'ham'}: pass + sig = inspect.signature(foo) + ba = sig.bind(20, 30, z={}) + + for ver in range(pickle.HIGHEST_PROTOCOL + 1): + with self.subTest(pickle_ver=ver): + ba_pickled = pickle.loads(pickle.dumps(ba, ver)) + self.assertEqual(ba, ba_pickled) + class TestSignaturePrivateHelpers(unittest.TestCase): def test_signature_get_bound_param(self): diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py index 1cf97dd..bda59bb 100644 --- a/Lib/test/test_io.py +++ b/Lib/test/test_io.py @@ -943,6 +943,71 @@ class BufferedReaderTest(unittest.TestCase, CommonBufferedTests): self.assertEqual(bufio.readinto(b), 1) self.assertEqual(b, b"cb") + def test_readinto1(self): + buffer_size = 10 + rawio = self.MockRawIO((b"abc", b"de", b"fgh", b"jkl")) + bufio = self.tp(rawio, buffer_size=buffer_size) + b = bytearray(2) + self.assertEqual(bufio.peek(3), b'abc') + self.assertEqual(rawio._reads, 1) + self.assertEqual(bufio.readinto1(b), 2) + self.assertEqual(b, b"ab") + self.assertEqual(rawio._reads, 1) + self.assertEqual(bufio.readinto1(b), 1) + self.assertEqual(b[:1], b"c") + self.assertEqual(rawio._reads, 1) + self.assertEqual(bufio.readinto1(b), 2) + self.assertEqual(b, b"de") + self.assertEqual(rawio._reads, 2) + b = bytearray(2*buffer_size) + self.assertEqual(bufio.peek(3), b'fgh') + self.assertEqual(rawio._reads, 3) + self.assertEqual(bufio.readinto1(b), 6) + self.assertEqual(b[:6], b"fghjkl") + self.assertEqual(rawio._reads, 4) + + def test_readinto_array(self): + buffer_size = 60 + data = b"a" * 26 + rawio = self.MockRawIO((data,)) + bufio = self.tp(rawio, buffer_size=buffer_size) + + # Create an array with element size > 1 byte + b = array.array('i', b'x' * 32) + assert len(b) != 16 + + # Read into it. We should get as many *bytes* as we can fit into b + # (which is more than the number of elements) + n = bufio.readinto(b) + self.assertGreater(n, len(b)) + + # Check that old contents of b are preserved + bm = memoryview(b).cast('B') + self.assertLess(n, len(bm)) + self.assertEqual(bm[:n], data[:n]) + self.assertEqual(bm[n:], b'x' * (len(bm[n:]))) + + def test_readinto1_array(self): + buffer_size = 60 + data = b"a" * 26 + rawio = self.MockRawIO((data,)) + bufio = self.tp(rawio, buffer_size=buffer_size) + + # Create an array with element size > 1 byte + b = array.array('i', b'x' * 32) + assert len(b) != 16 + + # Read into it. We should get as many *bytes* as we can fit into b + # (which is more than the number of elements) + n = bufio.readinto1(b) + self.assertGreater(n, len(b)) + + # Check that old contents of b are preserved + bm = memoryview(b).cast('B') + self.assertLess(n, len(bm)) + self.assertEqual(bm[:n], data[:n]) + self.assertEqual(bm[n:], b'x' * (len(bm[n:]))) + def test_readlines(self): def bufio(): rawio = self.MockRawIO((b"abc\n", b"d\n", b"ef")) @@ -2778,6 +2843,34 @@ class TextIOWrapperTest(unittest.TestCase): self.assertFalse(err) self.assertEqual("ok", out.decode().strip()) + def test_read_byteslike(self): + r = MemviewBytesIO(b'Just some random string\n') + t = self.TextIOWrapper(r, 'utf-8') + + # TextIOwrapper will not read the full string, because + # we truncate it to a multiple of the native int size + # so that we can construct a more complex memoryview. + bytes_val = _to_memoryview(r.getvalue()).tobytes() + + self.assertEqual(t.read(200), bytes_val.decode('utf-8')) + +class MemviewBytesIO(io.BytesIO): + '''A BytesIO object whose read method returns memoryviews + rather than bytes''' + + def read1(self, len_): + return _to_memoryview(super().read1(len_)) + + def read(self, len_): + return _to_memoryview(super().read(len_)) + +def _to_memoryview(buf): + '''Convert bytes-object *buf* to a non-trivial memoryview''' + + arr = array.array('i') + idx = len(buf) - len(buf) % arr.itemsize + arr.frombytes(buf[:idx]) + return memoryview(arr) class CTextIOWrapperTest(TextIOWrapperTest): io = io @@ -3022,6 +3115,8 @@ class MiscIOTest(unittest.TestCase): self.assertRaises(ValueError, f.readall) if hasattr(f, "readinto"): self.assertRaises(ValueError, f.readinto, bytearray(1024)) + if hasattr(f, "readinto1"): + self.assertRaises(ValueError, f.readinto1, bytearray(1024)) self.assertRaises(ValueError, f.readline) self.assertRaises(ValueError, f.readlines) self.assertRaises(ValueError, f.seek, 0) diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py index f2947b9..0b71bf8 100644 --- a/Lib/test/test_ipaddress.py +++ b/Lib/test/test_ipaddress.py @@ -628,6 +628,119 @@ class IpaddrUnitTest(unittest.TestCase): self.assertEqual("IPv6Interface('::1/128')", repr(ipaddress.IPv6Interface('::1'))) + # issue #16531: constructing IPv4Network from a (address, mask) tuple + def testIPv4Tuple(self): + # /32 + ip = ipaddress.IPv4Address('192.0.2.1') + net = ipaddress.IPv4Network('192.0.2.1/32') + self.assertEqual(ipaddress.IPv4Network(('192.0.2.1', 32)), net) + self.assertEqual(ipaddress.IPv4Network((ip, 32)), net) + self.assertEqual(ipaddress.IPv4Network((3221225985, 32)), net) + self.assertEqual(ipaddress.IPv4Network(('192.0.2.1', + '255.255.255.255')), net) + self.assertEqual(ipaddress.IPv4Network((ip, + '255.255.255.255')), net) + self.assertEqual(ipaddress.IPv4Network((3221225985, + '255.255.255.255')), net) + # strict=True and host bits set + with self.assertRaises(ValueError): + ipaddress.IPv4Network(('192.0.2.1', 24)) + with self.assertRaises(ValueError): + ipaddress.IPv4Network((ip, 24)) + with self.assertRaises(ValueError): + ipaddress.IPv4Network((3221225985, 24)) + with self.assertRaises(ValueError): + ipaddress.IPv4Network(('192.0.2.1', '255.255.255.0')) + with self.assertRaises(ValueError): + ipaddress.IPv4Network((ip, '255.255.255.0')) + with self.assertRaises(ValueError): + ipaddress.IPv4Network((3221225985, '255.255.255.0')) + # strict=False and host bits set + net = ipaddress.IPv4Network('192.0.2.0/24') + self.assertEqual(ipaddress.IPv4Network(('192.0.2.1', 24), + strict=False), net) + self.assertEqual(ipaddress.IPv4Network((ip, 24), + strict=False), net) + self.assertEqual(ipaddress.IPv4Network((3221225985, 24), + strict=False), net) + self.assertEqual(ipaddress.IPv4Network(('192.0.2.1', + '255.255.255.0'), + strict=False), net) + self.assertEqual(ipaddress.IPv4Network((ip, + '255.255.255.0'), + strict=False), net) + self.assertEqual(ipaddress.IPv4Network((3221225985, + '255.255.255.0'), + strict=False), net) + + # /24 + ip = ipaddress.IPv4Address('192.0.2.0') + net = ipaddress.IPv4Network('192.0.2.0/24') + self.assertEqual(ipaddress.IPv4Network(('192.0.2.0', + '255.255.255.0')), net) + self.assertEqual(ipaddress.IPv4Network((ip, + '255.255.255.0')), net) + self.assertEqual(ipaddress.IPv4Network((3221225984, + '255.255.255.0')), net) + self.assertEqual(ipaddress.IPv4Network(('192.0.2.0', 24)), net) + self.assertEqual(ipaddress.IPv4Network((ip, 24)), net) + self.assertEqual(ipaddress.IPv4Network((3221225984, 24)), net) + + self.assertEqual(ipaddress.IPv4Interface(('192.0.2.1', 24)), + ipaddress.IPv4Interface('192.0.2.1/24')) + self.assertEqual(ipaddress.IPv4Interface((3221225985, 24)), + ipaddress.IPv4Interface('192.0.2.1/24')) + + # issue #16531: constructing IPv6Network from a (address, mask) tuple + def testIPv6Tuple(self): + # /128 + ip = ipaddress.IPv6Address('2001:db8::') + net = ipaddress.IPv6Network('2001:db8::/128') + self.assertEqual(ipaddress.IPv6Network(('2001:db8::', '128')), + net) + self.assertEqual(ipaddress.IPv6Network( + (42540766411282592856903984951653826560, 128)), + net) + self.assertEqual(ipaddress.IPv6Network((ip, '128')), + net) + ip = ipaddress.IPv6Address('2001:db8::') + net = ipaddress.IPv6Network('2001:db8::/96') + self.assertEqual(ipaddress.IPv6Network(('2001:db8::', '96')), + net) + self.assertEqual(ipaddress.IPv6Network( + (42540766411282592856903984951653826560, 96)), + net) + self.assertEqual(ipaddress.IPv6Network((ip, '96')), + net) + + # strict=True and host bits set + ip = ipaddress.IPv6Address('2001:db8::1') + with self.assertRaises(ValueError): + ipaddress.IPv6Network(('2001:db8::1', 96)) + with self.assertRaises(ValueError): + ipaddress.IPv6Network(( + 42540766411282592856903984951653826561, 96)) + with self.assertRaises(ValueError): + ipaddress.IPv6Network((ip, 96)) + # strict=False and host bits set + net = ipaddress.IPv6Network('2001:db8::/96') + self.assertEqual(ipaddress.IPv6Network(('2001:db8::1', 96), + strict=False), + net) + self.assertEqual(ipaddress.IPv6Network( + (42540766411282592856903984951653826561, 96), + strict=False), + net) + self.assertEqual(ipaddress.IPv6Network((ip, 96), strict=False), + net) + + # /96 + self.assertEqual(ipaddress.IPv6Interface(('2001:db8::1', '96')), + ipaddress.IPv6Interface('2001:db8::1/96')) + self.assertEqual(ipaddress.IPv6Interface( + (42540766411282592856903984951653826561, '96')), + ipaddress.IPv6Interface('2001:db8::1/96')) + # issue57 def testAddressIntMath(self): self.assertEqual(ipaddress.IPv4Address('1.1.1.1') + 255, @@ -1593,6 +1706,14 @@ class IpaddrUnitTest(unittest.TestCase): addr3.exploded) self.assertEqual('192.168.178.1', addr4.exploded) + def testReversePointer(self): + addr1 = ipaddress.IPv4Address('127.0.0.1') + addr2 = ipaddress.IPv6Address('2001:db8::1') + self.assertEqual('1.0.0.127.in-addr.arpa', addr1.reverse_pointer) + self.assertEqual('1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.' + + 'b.d.0.1.0.0.2.ip6.arpa', + addr2.reverse_pointer) + def testIntRepresentation(self): self.assertEqual(16909060, int(self.ipv4_address)) self.assertEqual(42540616829182469433547762482097946625, diff --git a/Lib/test/test_json/test_tool.py b/Lib/test/test_json/test_tool.py index 0c39e56..5484a8a 100644 --- a/Lib/test/test_json/test_tool.py +++ b/Lib/test/test_json/test_tool.py @@ -55,6 +55,7 @@ class TestTool(unittest.TestCase): def test_infile_stdout(self): infile = self._create_infile() rc, out, err = assert_python_ok('-m', 'json.tool', infile) + self.assertEqual(rc, 0) self.assertEqual(out.splitlines(), self.expect.encode().splitlines()) self.assertEqual(err, b'') @@ -65,5 +66,12 @@ class TestTool(unittest.TestCase): self.addCleanup(os.remove, outfile) with open(outfile, "r") as fp: self.assertEqual(fp.read(), self.expect) + self.assertEqual(rc, 0) self.assertEqual(out, b'') self.assertEqual(err, b'') + + def test_help_flag(self): + rc, out, err = assert_python_ok('-m', 'json.tool', '-h') + self.assertEqual(rc, 0) + self.assertTrue(out.startswith(b'usage: ')) + self.assertEqual(err, b'') diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py index 6f6dd18..52412d1 100644 --- a/Lib/test/test_logging.py +++ b/Lib/test/test_logging.py @@ -1,4 +1,4 @@ -# Copyright 2001-2013 by Vinay Sajip. All Rights Reserved. +# Copyright 2001-2014 by Vinay Sajip. All Rights Reserved. # # Permission to use, copy, modify, and distribute this software and its # documentation for any purpose and without fee is hereby granted, @@ -16,7 +16,7 @@ """Test harness for the logging module. Run all tests. -Copyright (C) 2001-2013 Vinay Sajip. All Rights Reserved. +Copyright (C) 2001-2014 Vinay Sajip. All Rights Reserved. """ import logging @@ -34,14 +34,12 @@ import os import queue import random import re -import select import socket import struct import sys import tempfile from test.script_helper import assert_python_ok -from test.support import (captured_stdout, run_with_locale, run_unittest, - patch, requires_zlib, TestHandler, Matcher) +from test import support import textwrap import time import unittest @@ -51,16 +49,12 @@ try: import threading # The following imports are needed only for tests which # require threading - import asynchat import asyncore - import errno from http.server import HTTPServer, BaseHTTPRequestHandler import smtpd from urllib.parse import urlparse, parse_qs from socketserver import (ThreadingUDPServer, DatagramRequestHandler, - ThreadingTCPServer, StreamRequestHandler, - ThreadingUnixStreamServer, - ThreadingUnixDatagramServer) + ThreadingTCPServer, StreamRequestHandler) except ImportError: threading = None try: @@ -641,22 +635,23 @@ class StreamHandlerTest(BaseTest): h = TestStreamHandler(BadStream()) r = logging.makeLogRecord({}) old_raise = logging.raiseExceptions - old_stderr = sys.stderr + try: h.handle(r) self.assertIs(h.error_record, r) + h = logging.StreamHandler(BadStream()) - sys.stderr = sio = io.StringIO() - h.handle(r) - self.assertIn('\nRuntimeError: deliberate mistake\n', - sio.getvalue()) + with support.captured_stderr() as stderr: + h.handle(r) + msg = '\nRuntimeError: deliberate mistake\n' + self.assertIn(msg, stderr.getvalue()) + logging.raiseExceptions = False - sys.stderr = sio = io.StringIO() - h.handle(r) - self.assertEqual('', sio.getvalue()) + with support.captured_stderr() as stderr: + h.handle(r) + self.assertEqual('', stderr.getvalue()) finally: logging.raiseExceptions = old_raise - sys.stderr = old_stderr # -- The following section could be moved into a server_helper.py module # -- if it proves to be of wider utility than just test_logging @@ -684,7 +679,8 @@ if threading: """ def __init__(self, addr, handler, poll_interval, sockmap): - smtpd.SMTPServer.__init__(self, addr, None, map=sockmap) + smtpd.SMTPServer.__init__(self, addr, None, map=sockmap, + decode_data=True) self.port = self.socket.getsockname()[1] self._handler = handler self._thread = None @@ -1245,7 +1241,7 @@ class ConfigFileTest(BaseTest): def test_config0_ok(self): # A simple config file which overrides the default settings. - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config0) logger = logging.getLogger() # Won't output anything @@ -1260,7 +1256,7 @@ class ConfigFileTest(BaseTest): def test_config0_using_cp_ok(self): # A simple config file which overrides the default settings. - with captured_stdout() as output: + with support.captured_stdout() as output: file = io.StringIO(textwrap.dedent(self.config0)) cp = configparser.ConfigParser() cp.read_file(file) @@ -1278,7 +1274,7 @@ class ConfigFileTest(BaseTest): def test_config1_ok(self, config=config1): # A config file defining a sub-parser as well. - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(config) logger = logging.getLogger("compiler.parser") # Both will output a message @@ -1301,7 +1297,7 @@ class ConfigFileTest(BaseTest): def test_config4_ok(self): # A config file specifying a custom formatter class. - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config4) logger = logging.getLogger() try: @@ -1321,7 +1317,7 @@ class ConfigFileTest(BaseTest): self.test_config1_ok(config=self.config6) def test_config7_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config1a) logger = logging.getLogger("compiler.parser") # See issue #11424. compiler-hyphenated sorts @@ -1341,7 +1337,7 @@ class ConfigFileTest(BaseTest): ], stream=output) # Original logger output is empty. self.assert_log_lines([]) - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config7) logger = logging.getLogger("compiler.parser") self.assertFalse(logger.disabled) @@ -2516,7 +2512,7 @@ class ConfigDictTest(BaseTest): def test_config0_ok(self): # A simple config which overrides the default settings. - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config0) logger = logging.getLogger() # Won't output anything @@ -2531,7 +2527,7 @@ class ConfigDictTest(BaseTest): def test_config1_ok(self, config=config1): # A config defining a sub-parser as well. - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(config) logger = logging.getLogger("compiler.parser") # Both will output a message @@ -2562,7 +2558,7 @@ class ConfigDictTest(BaseTest): def test_config4_ok(self): # A config specifying a custom formatter class. - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config4) #logger = logging.getLogger() try: @@ -2577,7 +2573,7 @@ class ConfigDictTest(BaseTest): def test_config4a_ok(self): # A config specifying a custom formatter class. - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config4a) #logger = logging.getLogger() try: @@ -2597,7 +2593,7 @@ class ConfigDictTest(BaseTest): self.assertRaises(Exception, self.apply_config, self.config6) def test_config7_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config1) logger = logging.getLogger("compiler.parser") # Both will output a message @@ -2609,7 +2605,7 @@ class ConfigDictTest(BaseTest): ], stream=output) # Original logger output is empty. self.assert_log_lines([]) - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config7) logger = logging.getLogger("compiler.parser") self.assertTrue(logger.disabled) @@ -2626,7 +2622,7 @@ class ConfigDictTest(BaseTest): #Same as test_config_7_ok but don't disable old loggers. def test_config_8_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config1) logger = logging.getLogger("compiler.parser") # All will output a message @@ -2638,7 +2634,7 @@ class ConfigDictTest(BaseTest): ], stream=output) # Original logger output is empty. self.assert_log_lines([]) - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config8) logger = logging.getLogger("compiler.parser") self.assertFalse(logger.disabled) @@ -2659,7 +2655,7 @@ class ConfigDictTest(BaseTest): self.assert_log_lines([]) def test_config_8a_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config1a) logger = logging.getLogger("compiler.parser") # See issue #11424. compiler-hyphenated sorts @@ -2679,7 +2675,7 @@ class ConfigDictTest(BaseTest): ], stream=output) # Original logger output is empty. self.assert_log_lines([]) - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config8a) logger = logging.getLogger("compiler.parser") self.assertFalse(logger.disabled) @@ -2702,7 +2698,7 @@ class ConfigDictTest(BaseTest): self.assert_log_lines([]) def test_config_9_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config9) logger = logging.getLogger("compiler.parser") #Nothing will be output since both handler and logger are set to WARNING @@ -2720,7 +2716,7 @@ class ConfigDictTest(BaseTest): ], stream=output) def test_config_10_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config10) logger = logging.getLogger("compiler.parser") logger.warning(self.next_message()) @@ -2748,7 +2744,7 @@ class ConfigDictTest(BaseTest): self.assertRaises(Exception, self.apply_config, self.config13) def test_config14_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.apply_config(self.config14) h = logging._handlers['hand1'] self.assertEqual(h.foo, 'bar') @@ -2787,7 +2783,7 @@ class ConfigDictTest(BaseTest): @unittest.skipUnless(threading, 'Threading required for this test.') def test_listen_config_10_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.setup_via_listener(json.dumps(self.config10)) logger = logging.getLogger("compiler.parser") logger.warning(self.next_message()) @@ -2807,7 +2803,7 @@ class ConfigDictTest(BaseTest): @unittest.skipUnless(threading, 'Threading required for this test.') def test_listen_config_1_ok(self): - with captured_stdout() as output: + with support.captured_stdout() as output: self.setup_via_listener(textwrap.dedent(ConfigFileTest.config1)) logger = logging.getLogger("compiler.parser") # Both will output a message @@ -2834,7 +2830,7 @@ class ConfigDictTest(BaseTest): # First, specify a verification function that will fail. # We expect to see no output, since our configuration # never took effect. - with captured_stdout() as output: + with support.captured_stdout() as output: self.setup_via_listener(to_send, verify_fail) # Both will output a message logger.info(self.next_message()) @@ -2849,7 +2845,7 @@ class ConfigDictTest(BaseTest): # Now, perform no verification. Our configuration # should take effect. - with captured_stdout() as output: + with support.captured_stdout() as output: self.setup_via_listener(to_send) # no verify callable specified logger = logging.getLogger("compiler.parser") # Both will output a message @@ -2867,7 +2863,7 @@ class ConfigDictTest(BaseTest): # Now, perform verification which transforms the bytes. - with captured_stdout() as output: + with support.captured_stdout() as output: self.setup_via_listener(to_send[::-1], verify_reverse) logger = logging.getLogger("compiler.parser") # Both will output a message @@ -3022,7 +3018,7 @@ class QueueHandlerTest(BaseTest): @unittest.skipUnless(hasattr(logging.handlers, 'QueueListener'), 'logging.handlers.QueueListener required for this test') def test_queue_listener(self): - handler = TestHandler(Matcher()) + handler = support.TestHandler(support.Matcher()) listener = logging.handlers.QueueListener(self.queue, handler) listener.start() try: @@ -3190,32 +3186,35 @@ class LastResortTest(BaseTest): # Test the last resort handler root = self.root_logger root.removeHandler(self.root_hdlr) - old_stderr = sys.stderr old_lastresort = logging.lastResort old_raise_exceptions = logging.raiseExceptions + try: - sys.stderr = sio = io.StringIO() - root.debug('This should not appear') - self.assertEqual(sio.getvalue(), '') - root.warning('This is your final chance!') - self.assertEqual(sio.getvalue(), 'This is your final chance!\n') - #No handlers and no last resort, so 'No handlers' message + with support.captured_stderr() as stderr: + root.debug('This should not appear') + self.assertEqual(stderr.getvalue(), '') + root.warning('Final chance!') + self.assertEqual(stderr.getvalue(), 'Final chance!\n') + + # No handlers and no last resort, so 'No handlers' message logging.lastResort = None - sys.stderr = sio = io.StringIO() - root.warning('This is your final chance!') - self.assertEqual(sio.getvalue(), 'No handlers could be found for logger "root"\n') + with support.captured_stderr() as stderr: + root.warning('Final chance!') + msg = 'No handlers could be found for logger "root"\n' + self.assertEqual(stderr.getvalue(), msg) + # 'No handlers' message only printed once - sys.stderr = sio = io.StringIO() - root.warning('This is your final chance!') - self.assertEqual(sio.getvalue(), '') + with support.captured_stderr() as stderr: + root.warning('Final chance!') + self.assertEqual(stderr.getvalue(), '') + + # If raiseExceptions is False, no message is printed root.manager.emittedNoHandlerWarning = False - #If raiseExceptions is False, no message is printed logging.raiseExceptions = False - sys.stderr = sio = io.StringIO() - root.warning('This is your final chance!') - self.assertEqual(sio.getvalue(), '') + with support.captured_stderr() as stderr: + root.warning('Final chance!') + self.assertEqual(stderr.getvalue(), '') finally: - sys.stderr = old_stderr root.addHandler(self.root_hdlr) logging.lastResort = old_lastresort logging.raiseExceptions = old_raise_exceptions @@ -3346,8 +3345,8 @@ class ModuleLevelMiscTest(BaseTest): def _test_log(self, method, level=None): called = [] - patch(self, logging, 'basicConfig', - lambda *a, **kw: called.append((a, kw))) + support.patch(self, logging, 'basicConfig', + lambda *a, **kw: called.append((a, kw))) recording = RecordingHandler() logging.root.addHandler(recording) @@ -3518,7 +3517,7 @@ class BasicConfigTest(unittest.TestCase): self.assertEqual(logging.root.level, self.original_logging_level) def test_strformatstyle(self): - with captured_stdout() as output: + with support.captured_stdout() as output: logging.basicConfig(stream=sys.stdout, style="{") logging.error("Log an error") sys.stdout.seek(0) @@ -3526,7 +3525,7 @@ class BasicConfigTest(unittest.TestCase): "ERROR:root:Log an error") def test_stringtemplatestyle(self): - with captured_stdout() as output: + with support.captured_stdout() as output: logging.basicConfig(stream=sys.stdout, style="$") logging.error("Log an error") sys.stdout.seek(0) @@ -3643,7 +3642,7 @@ class BasicConfigTest(unittest.TestCase): self.addCleanup(logging.root.setLevel, old_level) called.append((a, kw)) - patch(self, logging, 'basicConfig', my_basic_config) + support.patch(self, logging, 'basicConfig', my_basic_config) log_method = getattr(logging, method) if level is not None: @@ -3783,8 +3782,8 @@ class LoggerTest(BaseTest): def test_find_caller_with_stack_info(self): called = [] - patch(self, logging.traceback, 'print_stack', - lambda f, file: called.append(file.getvalue())) + support.patch(self, logging.traceback, 'print_stack', + lambda f, file: called.append(file.getvalue())) self.logger.findCaller(stack_info=True) @@ -3921,7 +3920,7 @@ class RotatingFileHandlerTest(BaseFileTest): self.assertFalse(os.path.exists(namer(self.fn + ".3"))) rh.close() - @requires_zlib + @support.requires_zlib def test_rotator(self): def namer(name): return name + ".gz" @@ -4154,22 +4153,20 @@ class NTEventLogHandlerTest(BaseTest): # Set the locale to the platform-dependent default. I have no idea # why the test does this, but in any case we save the current locale # first and restore it at the end. -@run_with_locale('LC_ALL', '') +@support.run_with_locale('LC_ALL', '') def test_main(): - run_unittest(BuiltinLevelsTest, BasicFilterTest, - CustomLevelsAndFiltersTest, HandlerTest, MemoryHandlerTest, - ConfigFileTest, SocketHandlerTest, DatagramHandlerTest, - MemoryTest, EncodingTest, WarningsTest, ConfigDictTest, - ManagerTest, FormatterTest, BufferingFormatterTest, - StreamHandlerTest, LogRecordFactoryTest, ChildLoggerTest, - QueueHandlerTest, ShutdownTest, ModuleLevelMiscTest, - BasicConfigTest, LoggerAdapterTest, LoggerTest, - SMTPHandlerTest, FileHandlerTest, RotatingFileHandlerTest, - LastResortTest, LogRecordTest, ExceptionTest, - SysLogHandlerTest, HTTPHandlerTest, NTEventLogHandlerTest, - TimedRotatingFileHandlerTest, UnixSocketHandlerTest, - UnixDatagramHandlerTest, UnixSysLogHandlerTest - ) + support.run_unittest( + BuiltinLevelsTest, BasicFilterTest, CustomLevelsAndFiltersTest, + HandlerTest, MemoryHandlerTest, ConfigFileTest, SocketHandlerTest, + DatagramHandlerTest, MemoryTest, EncodingTest, WarningsTest, + ConfigDictTest, ManagerTest, FormatterTest, BufferingFormatterTest, + StreamHandlerTest, LogRecordFactoryTest, ChildLoggerTest, + QueueHandlerTest, ShutdownTest, ModuleLevelMiscTest, BasicConfigTest, + LoggerAdapterTest, LoggerTest, SMTPHandlerTest, FileHandlerTest, + RotatingFileHandlerTest, LastResortTest, LogRecordTest, + ExceptionTest, SysLogHandlerTest, HTTPHandlerTest, + NTEventLogHandlerTest, TimedRotatingFileHandlerTest, + UnixSocketHandlerTest, UnixDatagramHandlerTest, UnixSysLogHandlerTest) if __name__ == "__main__": test_main() diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py index 48f84ba..c9f3f16 100644 --- a/Lib/test/test_math.py +++ b/Lib/test/test_math.py @@ -422,9 +422,17 @@ class MathTests(unittest.TestCase): self.assertEqual(math.factorial(i), py_factorial(i)) self.assertRaises(ValueError, math.factorial, -1) self.assertRaises(ValueError, math.factorial, -1.0) + self.assertRaises(ValueError, math.factorial, -10**100) + self.assertRaises(ValueError, math.factorial, -1e100) self.assertRaises(ValueError, math.factorial, math.pi) - self.assertRaises(OverflowError, math.factorial, sys.maxsize+1) - self.assertRaises(OverflowError, math.factorial, 10e100) + + # Other implementations may place different upper bounds. + @support.cpython_only + def testFactorialHugeInputs(self): + # Currently raises ValueError for inputs that are too large + # to fit into a C long. + self.assertRaises(OverflowError, math.factorial, 10**100) + self.assertRaises(OverflowError, math.factorial, 1e100) def testFloor(self): self.assertRaises(TypeError, math.floor) diff --git a/Lib/test/test_module.py b/Lib/test/test_module.py index 1230293..9da3536 100644 --- a/Lib/test/test_module.py +++ b/Lib/test/test_module.py @@ -30,6 +30,22 @@ class ModuleTests(unittest.TestCase): pass self.assertEqual(foo.__doc__, ModuleType.__doc__) + def test_unintialized_missing_getattr(self): + # Issue 8297 + # test the text in the AttributeError of an uninitialized module + foo = ModuleType.__new__(ModuleType) + self.assertRaisesRegex( + AttributeError, "module has no attribute 'not_here'", + getattr, foo, "not_here") + + def test_missing_getattr(self): + # Issue 8297 + # test the text in the AttributeError + foo = ModuleType("foo") + self.assertRaisesRegex( + AttributeError, "module 'foo' has no attribute 'not_here'", + getattr, foo, "not_here") + def test_no_docstring(self): # Regularly initialized module, no docstring foo = ModuleType("foo") @@ -211,6 +227,14 @@ a = A(destroyed)""" b"len = len", b"shutil.rmtree = rmtree"}) + def test_descriptor_errors_propogate(self): + class Descr: + def __get__(self, o, t): + raise RuntimeError + class M(ModuleType): + melon = Descr() + self.assertRaises(RuntimeError, getattr, M("mymod"), "melon") + # frozen and namespace module reprs are tested in importlib. diff --git a/Lib/test/test_operator.py b/Lib/test/test_operator.py index ab58a98..1bd0391 100644 --- a/Lib/test/test_operator.py +++ b/Lib/test/test_operator.py @@ -203,6 +203,15 @@ class OperatorTestCase: self.assertRaises(TypeError, operator.mul, None, None) self.assertTrue(operator.mul(5, 2) == 10) + def test_matmul(self): + operator = self.module + self.assertRaises(TypeError, operator.matmul) + self.assertRaises(TypeError, operator.matmul, 42, 42) + class M: + def __matmul__(self, other): + return other - 1 + self.assertEqual(M() @ 42, 41) + def test_neg(self): operator = self.module self.assertRaises(TypeError, operator.neg) @@ -416,6 +425,7 @@ class OperatorTestCase: def __ilshift__ (self, other): return "ilshift" def __imod__ (self, other): return "imod" def __imul__ (self, other): return "imul" + def __imatmul__ (self, other): return "imatmul" def __ior__ (self, other): return "ior" def __ipow__ (self, other): return "ipow" def __irshift__ (self, other): return "irshift" @@ -430,6 +440,7 @@ class OperatorTestCase: self.assertEqual(operator.ilshift (c, 5), "ilshift") self.assertEqual(operator.imod (c, 5), "imod") self.assertEqual(operator.imul (c, 5), "imul") + self.assertEqual(operator.imatmul (c, 5), "imatmul") self.assertEqual(operator.ior (c, 5), "ior") self.assertEqual(operator.ipow (c, 5), "ipow") self.assertEqual(operator.irshift (c, 5), "irshift") diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py index e129bef..e669df8 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -39,6 +39,14 @@ try: import fcntl except ImportError: fcntl = None +try: + import _winapi +except ImportError: + _winapi = None +try: + from _testcapi import INT_MAX, PY_SSIZE_T_MAX +except ImportError: + INT_MAX = PY_SSIZE_T_MAX = sys.maxsize from test.script_helper import assert_python_ok @@ -115,6 +123,26 @@ class FileTests(unittest.TestCase): self.assertEqual(type(s), bytes) self.assertEqual(s, b"spam") + @support.cpython_only + # Skip the test on 32-bit platforms: the number of bytes must fit in a + # Py_ssize_t type + @unittest.skipUnless(INT_MAX < PY_SSIZE_T_MAX, + "needs INT_MAX < PY_SSIZE_T_MAX") + @support.bigmemtest(size=INT_MAX + 10, memuse=1, dry_run=False) + def test_large_read(self, size): + with open(support.TESTFN, "wb") as fp: + fp.write(b'test') + self.addCleanup(support.unlink, support.TESTFN) + + # Issue #21932: Make sure that os.read() does not raise an + # OverflowError for size larger than INT_MAX + with open(support.TESTFN, "rb") as fp: + data = os.read(fp.fileno(), size) + + # The test does not try to read more than 2 GB at once because the + # operating system is free to return less bytes than requested. + self.assertEqual(data, b'test') + def test_write(self): # os.write() accepts bytes- and buffer-like objects but not strings fd = os.open(support.TESTFN, os.O_CREAT | os.O_WRONLY) @@ -526,6 +554,28 @@ class StatAttributeTests(unittest.TestCase): os.stat(r) self.assertEqual(ctx.exception.errno, errno.EBADF) + def check_file_attributes(self, result): + self.assertTrue(hasattr(result, 'st_file_attributes')) + self.assertTrue(isinstance(result.st_file_attributes, int)) + self.assertTrue(0 <= result.st_file_attributes <= 0xFFFFFFFF) + + @unittest.skipUnless(sys.platform == "win32", + "st_file_attributes is Win32 specific") + def test_file_attributes(self): + # test file st_file_attributes (FILE_ATTRIBUTE_DIRECTORY not set) + result = os.stat(self.fname) + self.check_file_attributes(result) + self.assertEqual( + result.st_file_attributes & stat.FILE_ATTRIBUTE_DIRECTORY, + 0) + + # test directory st_file_attributes (FILE_ATTRIBUTE_DIRECTORY set) + result = os.stat(support.TESTFN) + self.check_file_attributes(result) + self.assertEqual( + result.st_file_attributes & stat.FILE_ATTRIBUTE_DIRECTORY, + stat.FILE_ATTRIBUTE_DIRECTORY) + from test import mapping_tests class EnvironTests(mapping_tests.BasicTestMappingProtocol): @@ -1773,6 +1823,37 @@ class Win32SymlinkTests(unittest.TestCase): shutil.rmtree(level1) +@unittest.skipUnless(sys.platform == "win32", "Win32 specific tests") +class Win32JunctionTests(unittest.TestCase): + junction = 'junctiontest' + junction_target = os.path.dirname(os.path.abspath(__file__)) + + def setUp(self): + assert os.path.exists(self.junction_target) + assert not os.path.exists(self.junction) + + def tearDown(self): + if os.path.exists(self.junction): + # os.rmdir delegates to Windows' RemoveDirectoryW, + # which removes junction points safely. + os.rmdir(self.junction) + + def test_create_junction(self): + _winapi.CreateJunction(self.junction_target, self.junction) + self.assertTrue(os.path.exists(self.junction)) + self.assertTrue(os.path.isdir(self.junction)) + + # Junctions are not recognized as links. + self.assertFalse(os.path.islink(self.junction)) + + def test_unlink_removes_junction(self): + _winapi.CreateJunction(self.junction_target, self.junction) + self.assertTrue(os.path.exists(self.junction)) + + os.unlink(self.junction) + self.assertFalse(os.path.exists(self.junction)) + + @support.skip_unless_symlink class NonLocalSymlinkTests(unittest.TestCase): @@ -2544,6 +2625,7 @@ def test_main(): RemoveDirsTests, CPUCountTests, FDInheritanceTests, + Win32JunctionTests, ) if __name__ == "__main__": diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py index da001f0..d838e70 100644 --- a/Lib/test/test_pathlib.py +++ b/Lib/test/test_pathlib.py @@ -1265,6 +1265,26 @@ class _BasePathTest(object): p = self.cls.cwd() self._test_cwd(p) + def test_samefile(self): + fileA_path = os.path.join(BASE, 'fileA') + fileB_path = os.path.join(BASE, 'dirB', 'fileB') + p = self.cls(fileA_path) + pp = self.cls(fileA_path) + q = self.cls(fileB_path) + self.assertTrue(p.samefile(fileA_path)) + self.assertTrue(p.samefile(pp)) + self.assertFalse(p.samefile(fileB_path)) + self.assertFalse(p.samefile(q)) + # Test the non-existent file case + non_existent = os.path.join(BASE, 'foo') + r = self.cls(non_existent) + self.assertRaises(FileNotFoundError, p.samefile, r) + self.assertRaises(FileNotFoundError, p.samefile, non_existent) + self.assertRaises(FileNotFoundError, r.samefile, p) + self.assertRaises(FileNotFoundError, r.samefile, non_existent) + self.assertRaises(FileNotFoundError, r.samefile, r) + self.assertRaises(FileNotFoundError, r.samefile, non_existent) + def test_empty_path(self): # The empty path points to '.' p = self.cls('') diff --git a/Lib/test/test_poplib.py b/Lib/test/test_poplib.py index d076fc1..d695a0d 100644 --- a/Lib/test/test_poplib.py +++ b/Lib/test/test_poplib.py @@ -349,23 +349,18 @@ class TestPOP3Class(TestCase): if SUPPORTS_SSL: + from test.test_ftplib import SSLConnection - class DummyPOP3_SSLHandler(DummyPOP3Handler): + class DummyPOP3_SSLHandler(SSLConnection, DummyPOP3Handler): def __init__(self, conn): asynchat.async_chat.__init__(self, conn) - ssl_socket = ssl.wrap_socket(self.socket, certfile=CERTFILE, - server_side=True, - do_handshake_on_connect=False) - self.del_channel() - self.set_socket(ssl_socket) - # Must try handshake before calling push() - self.tls_active = True - self.tls_starting = True - self._do_tls_handshake() + self.secure_connection() self.set_terminator(b"\r\n") self.in_buffer = [] self.push('+OK dummy pop3 server ready. <timestamp>') + self.tls_active = True + self.tls_starting = False @requires_ssl diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py index a513fa6..bf808d3 100644 --- a/Lib/test/test_pydoc.py +++ b/Lib/test/test_pydoc.py @@ -2,7 +2,6 @@ import os import sys import builtins import contextlib -import difflib import inspect import pydoc import keyword @@ -357,15 +356,6 @@ def get_pydoc_text(module): output = patt.sub('', output) return output.strip(), loc -def print_diffs(text1, text2): - "Prints unified diffs for two texts" - # XXX now obsolete, use unittest built-in support - lines1 = text1.splitlines(keepends=True) - lines2 = text2.splitlines(keepends=True) - diffs = difflib.unified_diff(lines1, lines2, n=0, fromfile='expected', - tofile='got') - print('\n' + ''.join(diffs)) - def get_html_title(text): # Bit of hack, but good enough for test purposes header, _, _ = text.partition("</head>") @@ -411,9 +401,7 @@ class PydocDocTest(unittest.TestCase): expected_html = expected_html_pattern % ( (mod_url, mod_file, doc_loc) + expected_html_data_docstrings) - if result != expected_html: - print_diffs(expected_html, result) - self.fail("outputs are not equal, see diff above") + self.assertEqual(result, expected_html) @unittest.skipIf(sys.flags.optimize >= 2, "Docstrings are omitted with -O2 and above") @@ -426,9 +414,7 @@ class PydocDocTest(unittest.TestCase): (doc_loc,) + expected_text_data_docstrings + (inspect.getabsfile(pydoc_mod),)) - if result != expected_text: - print_diffs(expected_text, result) - self.fail("outputs are not equal, see diff above") + self.assertEqual(expected_text, result) def test_text_enum_member_with_value_zero(self): # Test issue #20654 to ensure enum member with value 0 can be @@ -884,9 +870,7 @@ class PydocWithMetaClasses(unittest.TestCase): expected_text = expected_dynamicattribute_pattern % ( (__name__,) + expected_text_data_docstrings[:2]) result = output.getvalue().strip() - if result != expected_text: - print_diffs(expected_text, result) - self.fail("outputs are not equal, see diff above") + self.assertEqual(expected_text, result) @unittest.skipIf(sys.flags.optimize >= 2, "Docstrings are omitted with -O2 and above") @@ -907,9 +891,7 @@ class PydocWithMetaClasses(unittest.TestCase): helper(Class) expected_text = expected_virtualattribute_pattern1 % __name__ result = output.getvalue().strip() - if result != expected_text: - print_diffs(expected_text, result) - self.fail("outputs are not equal, see diff above") + self.assertEqual(expected_text, result) @unittest.skipIf(sys.flags.optimize >= 2, "Docstrings are omitted with -O2 and above") @@ -949,19 +931,13 @@ class PydocWithMetaClasses(unittest.TestCase): helper(Class1) expected_text1 = expected_virtualattribute_pattern2 % __name__ result1 = output.getvalue().strip() - if result1 != expected_text1: - print_diffs(expected_text1, result1) - fail1 = True + self.assertEqual(expected_text1, result1) output = StringIO() helper = pydoc.Helper(output=output) helper(Class2) expected_text2 = expected_virtualattribute_pattern3 % __name__ result2 = output.getvalue().strip() - if result2 != expected_text2: - print_diffs(expected_text2, result2) - fail2 = True - if fail1 or fail2: - self.fail("outputs are not equal, see diff above") + self.assertEqual(expected_text2, result2) @unittest.skipIf(sys.flags.optimize >= 2, "Docstrings are omitted with -O2 and above") @@ -978,9 +954,7 @@ class PydocWithMetaClasses(unittest.TestCase): helper(C) expected_text = expected_missingattribute_pattern % __name__ result = output.getvalue().strip() - if result != expected_text: - print_diffs(expected_text, result) - self.fail("outputs are not equal, see diff above") + self.assertEqual(expected_text, result) @reap_threads diff --git a/Lib/test/test_selectors.py b/Lib/test/test_selectors.py index 34edd76..8f83c90 100644 --- a/Lib/test/test_selectors.py +++ b/Lib/test/test_selectors.py @@ -441,10 +441,18 @@ class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn): SELECTOR = getattr(selectors, 'KqueueSelector', None) +@unittest.skipUnless(hasattr(selectors, 'DevpollSelector'), + "Test needs selectors.DevpollSelector") +class DevpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn): + + SELECTOR = getattr(selectors, 'DevpollSelector', None) + + + def test_main(): tests = [DefaultSelectorTestCase, SelectSelectorTestCase, PollSelectorTestCase, EpollSelectorTestCase, - KqueueSelectorTestCase] + KqueueSelectorTestCase, DevpollSelectorTestCase] support.run_unittest(*tests) support.reap_children() diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py index bfef621..992a4ce 100644 --- a/Lib/test/test_set.py +++ b/Lib/test/test_set.py @@ -929,7 +929,7 @@ class TestBasicOpsString(TestBasicOps, unittest.TestCase): class TestBasicOpsBytes(TestBasicOps, unittest.TestCase): def setUp(self): - self.case = "string set" + self.case = "bytes set" self.values = [b"a", b"b", b"c"] self.set = set(self.values) self.dup = set(self.values) diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py index a483fe1..098d58e 100644 --- a/Lib/test/test_shutil.py +++ b/Lib/test/test_shutil.py @@ -1592,6 +1592,24 @@ class TestMove(unittest.TestCase): rv = shutil.move(self.src_file, os.path.join(self.dst_dir, 'bar')) self.assertEqual(rv, os.path.join(self.dst_dir, 'bar')) + @mock_rename + def test_move_file_special_function(self): + moved = [] + def _copy(src, dst): + moved.append((src, dst)) + shutil.move(self.src_file, self.dst_dir, copy_function=_copy) + self.assertEqual(len(moved), 1) + + @mock_rename + def test_move_dir_special_function(self): + moved = [] + def _copy(src, dst): + moved.append((src, dst)) + support.create_empty_file(os.path.join(self.src_dir, 'child')) + support.create_empty_file(os.path.join(self.src_dir, 'child1')) + shutil.move(self.src_dir, self.dst_dir, copy_function=_copy) + self.assertEqual(len(moved), 3) + class TestCopyFile(unittest.TestCase): diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py index 74f74af..92747cf 100644 --- a/Lib/test/test_signal.py +++ b/Lib/test/test_signal.py @@ -1,6 +1,7 @@ import unittest from test import support from contextlib import closing +import enum import gc import pickle import select @@ -39,6 +40,23 @@ def ignoring_eintr(__func, *args, **kwargs): return None +class GenericTests(unittest.TestCase): + + @unittest.skipIf(threading is None, "test needs threading module") + def test_enums(self): + for name in dir(signal): + sig = getattr(signal, name) + if name in {'SIG_DFL', 'SIG_IGN'}: + self.assertIsInstance(sig, signal.Handlers) + elif name in {'SIG_BLOCK', 'SIG_UNBLOCK', 'SIG_SETMASK'}: + self.assertIsInstance(sig, signal.Sigmasks) + elif name.startswith('SIG') and not name.startswith('SIG_'): + self.assertIsInstance(sig, signal.Signals) + elif name.startswith('CTRL_'): + self.assertIsInstance(sig, signal.Signals) + self.assertEqual(sys.platform, "win32") + + @unittest.skipIf(sys.platform == "win32", "Not valid on Windows") class InterProcessSignalTests(unittest.TestCase): MAX_DURATION = 20 # Entire test should last at most 20 sec. @@ -195,6 +213,7 @@ class PosixTests(unittest.TestCase): def test_getsignal(self): hup = signal.signal(signal.SIGHUP, self.trivial_signal_handler) + self.assertIsInstance(hup, signal.Handlers) self.assertEqual(signal.getsignal(signal.SIGHUP), self.trivial_signal_handler) signal.signal(signal.SIGHUP, hup) @@ -271,7 +290,7 @@ class WakeupSignalTests(unittest.TestCase): os.close(read) os.close(write) - """.format(signals, ordered, test_body) + """.format(tuple(map(int, signals)), ordered, test_body) assert_python_ok('-c', code) @@ -604,6 +623,8 @@ class PendingSignalsTests(unittest.TestCase): signal.pthread_sigmask(signal.SIG_BLOCK, [signum]) os.kill(os.getpid(), signum) pending = signal.sigpending() + for sig in pending: + assert isinstance(sig, signal.Signals), repr(pending) if pending != {signum}: raise Exception('%s != {%s}' % (pending, signum)) try: @@ -660,6 +681,7 @@ class PendingSignalsTests(unittest.TestCase): code = '''if 1: import signal import sys + from signal import Signals def handler(signum, frame): 1/0 @@ -702,6 +724,7 @@ class PendingSignalsTests(unittest.TestCase): def test(signum): signal.alarm(1) received = signal.sigwait([signum]) + assert isinstance(received, signal.Signals), received if received != signum: raise Exception('received %s, not %s' % (received, signum)) ''') @@ -842,8 +865,14 @@ class PendingSignalsTests(unittest.TestCase): def kill(signum): os.kill(os.getpid(), signum) + def check_mask(mask): + for sig in mask: + assert isinstance(sig, signal.Signals), repr(sig) + def read_sigmask(): - return signal.pthread_sigmask(signal.SIG_BLOCK, []) + sigmask = signal.pthread_sigmask(signal.SIG_BLOCK, []) + check_mask(sigmask) + return sigmask signum = signal.SIGUSR1 @@ -852,6 +881,7 @@ class PendingSignalsTests(unittest.TestCase): # Unblock SIGUSR1 (and copy the old mask) to test our signal handler old_mask = signal.pthread_sigmask(signal.SIG_UNBLOCK, [signum]) + check_mask(old_mask) try: kill(signum) except ZeroDivisionError: @@ -861,11 +891,13 @@ class PendingSignalsTests(unittest.TestCase): # Block and then raise SIGUSR1. The signal is blocked: the signal # handler is not called, and the signal is now pending - signal.pthread_sigmask(signal.SIG_BLOCK, [signum]) + mask = signal.pthread_sigmask(signal.SIG_BLOCK, [signum]) + check_mask(mask) kill(signum) # Check the new mask blocked = read_sigmask() + check_mask(blocked) if signum not in blocked: raise Exception("%s not in %s" % (signum, blocked)) if old_mask ^ blocked != {signum}: @@ -928,7 +960,7 @@ class PendingSignalsTests(unittest.TestCase): def test_main(): try: - support.run_unittest(PosixTests, InterProcessSignalTests, + support.run_unittest(GenericTests, PosixTests, InterProcessSignalTests, WakeupFDTests, WakeupSignalTests, SiginterruptTest, ItimerTest, WindowsSignalTests, PendingSignalsTests) diff --git a/Lib/test/test_site.py b/Lib/test/test_site.py index 8325222..c2f37f8 100644 --- a/Lib/test/test_site.py +++ b/Lib/test/test_site.py @@ -235,20 +235,18 @@ class HelperFunctionsTests(unittest.TestCase): # OS X framework builds site.PREFIXES = ['Python.framework'] dirs = site.getsitepackages() - self.assertEqual(len(dirs), 3) + self.assertEqual(len(dirs), 2) wanted = os.path.join('/Library', sysconfig.get_config_var("PYTHONFRAMEWORK"), sys.version[:3], 'site-packages') - self.assertEqual(dirs[2], wanted) + self.assertEqual(dirs[1], wanted) elif os.sep == '/': # OS X non-framwework builds, Linux, FreeBSD, etc - self.assertEqual(len(dirs), 2) + self.assertEqual(len(dirs), 1) wanted = os.path.join('xoxo', 'lib', 'python' + sys.version[:3], 'site-packages') self.assertEqual(dirs[0], wanted) - wanted = os.path.join('xoxo', 'lib', 'site-python') - self.assertEqual(dirs[1], wanted) else: # other platforms self.assertEqual(len(dirs), 2) diff --git a/Lib/test/test_smtpd.py b/Lib/test/test_smtpd.py index 93f14c4..caeb797 100644 --- a/Lib/test/test_smtpd.py +++ b/Lib/test/test_smtpd.py @@ -7,13 +7,18 @@ import asyncore class DummyServer(smtpd.SMTPServer): - def __init__(self, localaddr, remoteaddr): - smtpd.SMTPServer.__init__(self, localaddr, remoteaddr) + def __init__(self, localaddr, remoteaddr, decode_data=True): + smtpd.SMTPServer.__init__(self, localaddr, remoteaddr, + decode_data=decode_data) self.messages = [] + if decode_data: + self.return_status = 'return status' + else: + self.return_status = b'return status' def process_message(self, peer, mailfrom, rcpttos, data): self.messages.append((peer, mailfrom, rcpttos, data)) - if data == 'return status': + if data == self.return_status: return '250 Okish' @@ -31,9 +36,10 @@ class SMTPDServerTest(unittest.TestCase): smtpd.socket = asyncore.socket = mock_socket def test_process_message_unimplemented(self): - server = smtpd.SMTPServer('a', 'b') + server = smtpd.SMTPServer((support.HOST, 0), ('b', 0), + decode_data=True) conn, addr = server.accept() - channel = smtpd.SMTPChannel(server, conn, addr) + channel = smtpd.SMTPChannel(server, conn, addr, decode_data=True) def write_line(line): channel.socket.queue_recv(line) @@ -45,19 +51,44 @@ class SMTPDServerTest(unittest.TestCase): write_line(b'DATA') self.assertRaises(NotImplementedError, write_line, b'spam\r\n.\r\n') + def test_decode_data_default_warns(self): + with self.assertWarns(DeprecationWarning): + smtpd.SMTPServer((support.HOST, 0), ('b', 0)) + + def tearDown(self): + asyncore.close_all() + asyncore.socket = smtpd.socket = socket + + +class TestFamilyDetection(unittest.TestCase): + def setUp(self): + smtpd.socket = asyncore.socket = mock_socket + def tearDown(self): asyncore.close_all() asyncore.socket = smtpd.socket = socket + @unittest.skipUnless(support.IPV6_ENABLED, "IPv6 not enabled") + def test_socket_uses_IPv6(self): + server = smtpd.SMTPServer((support.HOSTv6, 0), (support.HOST, 0), + decode_data=False) + self.assertEqual(server.socket.family, socket.AF_INET6) + + def test_socket_uses_IPv4(self): + server = smtpd.SMTPServer((support.HOST, 0), (support.HOSTv6, 0), + decode_data=False) + self.assertEqual(server.socket.family, socket.AF_INET) + class SMTPDChannelTest(unittest.TestCase): def setUp(self): smtpd.socket = asyncore.socket = mock_socket self.old_debugstream = smtpd.DEBUGSTREAM self.debug = smtpd.DEBUGSTREAM = io.StringIO() - self.server = DummyServer('a', 'b') + self.server = DummyServer((support.HOST, 0), ('b', 0)) conn, addr = self.server.accept() - self.channel = smtpd.SMTPChannel(self.server, conn, addr) + self.channel = smtpd.SMTPChannel(self.server, conn, addr, + decode_data=True) def tearDown(self): asyncore.close_all() @@ -69,7 +100,9 @@ class SMTPDChannelTest(unittest.TestCase): self.channel.handle_read() def test_broken_connect(self): - self.assertRaises(DummyDispatcherBroken, BrokenDummyServer, 'a', 'b') + self.assertRaises( + DummyDispatcherBroken, BrokenDummyServer, + (support.HOST, 0), ('b', 0)) def test_server_accept(self): self.server.handle_accept() @@ -502,6 +535,22 @@ class SMTPDChannelTest(unittest.TestCase): with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__addr = 'spam' + def test_decode_data_default_warning(self): + server = DummyServer((support.HOST, 0), ('b', 0)) + conn, addr = self.server.accept() + with self.assertWarns(DeprecationWarning): + smtpd.SMTPChannel(server, conn, addr) + +@unittest.skipUnless(support.IPV6_ENABLED, "IPv6 not enabled") +class SMTPDChannelIPv6Test(SMTPDChannelTest): + def setUp(self): + smtpd.socket = asyncore.socket = mock_socket + self.old_debugstream = smtpd.DEBUGSTREAM + self.debug = smtpd.DEBUGSTREAM = io.StringIO() + self.server = DummyServer((support.HOSTv6, 0), ('b', 0)) + conn, addr = self.server.accept() + self.channel = smtpd.SMTPChannel(self.server, conn, addr, + decode_data=True) class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase): @@ -509,10 +558,11 @@ class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase): smtpd.socket = asyncore.socket = mock_socket self.old_debugstream = smtpd.DEBUGSTREAM self.debug = smtpd.DEBUGSTREAM = io.StringIO() - self.server = DummyServer('a', 'b') + self.server = DummyServer((support.HOST, 0), ('b', 0)) conn, addr = self.server.accept() # Set DATA size limit to 32 bytes for easy testing - self.channel = smtpd.SMTPChannel(self.server, conn, addr, 32) + self.channel = smtpd.SMTPChannel(self.server, conn, addr, 32, + decode_data=True) def tearDown(self): asyncore.close_all() @@ -553,5 +603,94 @@ class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase): b'552 Error: Too much mail data\r\n') +class SMTPDChannelWithDecodeDataFalse(unittest.TestCase): + + def setUp(self): + smtpd.socket = asyncore.socket = mock_socket + self.old_debugstream = smtpd.DEBUGSTREAM + self.debug = smtpd.DEBUGSTREAM = io.StringIO() + self.server = DummyServer((support.HOST, 0), ('b', 0), + decode_data=False) + conn, addr = self.server.accept() + # Set decode_data to False + self.channel = smtpd.SMTPChannel(self.server, conn, addr, + decode_data=False) + + def tearDown(self): + asyncore.close_all() + asyncore.socket = smtpd.socket = socket + smtpd.DEBUGSTREAM = self.old_debugstream + + def write_line(self, line): + self.channel.socket.queue_recv(line) + self.channel.handle_read() + + def test_ascii_data(self): + self.write_line(b'HELO example') + self.write_line(b'MAIL From:eggs@example') + self.write_line(b'RCPT To:spam@example') + self.write_line(b'DATA') + self.write_line(b'plain ascii text') + self.write_line(b'.') + self.assertEqual(self.channel.received_data, b'plain ascii text') + + def test_utf8_data(self): + self.write_line(b'HELO example') + self.write_line(b'MAIL From:eggs@example') + self.write_line(b'RCPT To:spam@example') + self.write_line(b'DATA') + self.write_line(b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87') + self.write_line(b'and some plain ascii') + self.write_line(b'.') + self.assertEqual( + self.channel.received_data, + b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87\n' + b'and some plain ascii') + + +class SMTPDChannelWithDecodeDataTrue(unittest.TestCase): + + def setUp(self): + smtpd.socket = asyncore.socket = mock_socket + self.old_debugstream = smtpd.DEBUGSTREAM + self.debug = smtpd.DEBUGSTREAM = io.StringIO() + self.server = DummyServer((support.HOST, 0), ('b', 0), + decode_data=True) + conn, addr = self.server.accept() + # Set decode_data to True + self.channel = smtpd.SMTPChannel(self.server, conn, addr, + decode_data=True) + + def tearDown(self): + asyncore.close_all() + asyncore.socket = smtpd.socket = socket + smtpd.DEBUGSTREAM = self.old_debugstream + + def write_line(self, line): + self.channel.socket.queue_recv(line) + self.channel.handle_read() + + def test_ascii_data(self): + self.write_line(b'HELO example') + self.write_line(b'MAIL From:eggs@example') + self.write_line(b'RCPT To:spam@example') + self.write_line(b'DATA') + self.write_line(b'plain ascii text') + self.write_line(b'.') + self.assertEqual(self.channel.received_data, 'plain ascii text') + + def test_utf8_data(self): + self.write_line(b'HELO example') + self.write_line(b'MAIL From:eggs@example') + self.write_line(b'RCPT To:spam@example') + self.write_line(b'DATA') + self.write_line(b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87') + self.write_line(b'and some plain ascii') + self.write_line(b'.') + self.assertEqual( + self.channel.received_data, + 'utf8 enriched text: żźć\nand some plain ascii') + + if __name__ == "__main__": unittest.main() diff --git a/Lib/test/test_smtplib.py b/Lib/test/test_smtplib.py index 16e90f4..784c422 100644 --- a/Lib/test/test_smtplib.py +++ b/Lib/test/test_smtplib.py @@ -10,6 +10,7 @@ import sys import time import select import errno +import base64 import unittest from test import support, mock_socket @@ -184,7 +185,8 @@ class DebuggingServerTests(unittest.TestCase): self.old_DEBUGSTREAM = smtpd.DEBUGSTREAM smtpd.DEBUGSTREAM = io.StringIO() # Pick a random unused port by passing 0 for the port number - self.serv = smtpd.DebuggingServer((HOST, 0), ('nowhere', -1)) + self.serv = smtpd.DebuggingServer((HOST, 0), ('nowhere', -1), + decode_data=True) # Keep a note of what port was assigned self.port = self.serv.socket.getsockname()[1] serv_args = (self.serv, self.serv_evt, self.client_evt) @@ -604,7 +606,8 @@ sim_auth_credentials = { 'cram-md5': ('TXIUQUBZB21LD2HLCMUUY29TIDG4OWQ0MJ' 'KWZGQ4ODNMNDA4NTGXMDRLZWMYZJDMODG1'), } -sim_auth_login_password = 'C29TZXBHC3N3B3JK' +sim_auth_login_user = 'TXIUQUBZB21LD2HLCMUUY29T' +sim_auth_plain = 'AE1YLKFAC29TZXDOZXJLLMNVBQBZB21LCGFZC3DVCMQ=' sim_lists = {'list-1':['Mr.A@somewhere.com','Mrs.C@somewhereesle.com'], 'list-2':['Ms.B@xn--fo-fka.com',], @@ -658,18 +661,16 @@ class SimSMTPChannel(smtpd.SMTPChannel): self.push('550 No access for you!') def smtp_AUTH(self, arg): - if arg.strip().lower()=='cram-md5': + mech = arg.strip().lower() + if mech=='cram-md5': self.push('334 {}'.format(sim_cram_md5_challenge)) - return - mech, auth = arg.split() - mech = mech.lower() - if mech not in sim_auth_credentials: + elif mech not in sim_auth_credentials: self.push('504 auth type unimplemented') return - if mech == 'plain' and auth==sim_auth_credentials['plain']: - self.push('235 plain auth ok') - elif mech=='login' and auth==sim_auth_credentials['login']: - self.push('334 Password:') + elif mech=='plain': + self.push('334 ') + elif mech=='login': + self.push('334 ') else: self.push('550 No access for you!') @@ -719,7 +720,8 @@ class SimSMTPServer(smtpd.SMTPServer): def handle_accepted(self, conn, addr): self._SMTPchannel = self.channel_class( - self._extra_features, self, conn, addr) + self._extra_features, self, conn, addr, + decode_data=self._decode_data) def process_message(self, peer, mailfrom, rcpttos, data): pass @@ -742,7 +744,7 @@ class SMTPSimTests(unittest.TestCase): self.serv_evt = threading.Event() self.client_evt = threading.Event() # Pick a random unused port by passing 0 for the port number - self.serv = SimSMTPServer((HOST, 0), ('nowhere', -1)) + self.serv = SimSMTPServer((HOST, 0), ('nowhere', -1), decode_data=True) # Keep a note of what port was assigned self.port = self.serv.socket.getsockname()[1] serv_args = (self.serv, self.serv_evt, self.client_evt) @@ -816,28 +818,28 @@ class SMTPSimTests(unittest.TestCase): self.assertEqual(smtp.expn(u), expected_unknown) smtp.quit() - def testAUTH_PLAIN(self): - self.serv.add_feature("AUTH PLAIN") - smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15) - - expected_auth_ok = (235, b'plain auth ok') - self.assertEqual(smtp.login(sim_auth[0], sim_auth[1]), expected_auth_ok) - smtp.close() - - # SimSMTPChannel doesn't fully support LOGIN or CRAM-MD5 auth because they - # require a synchronous read to obtain the credentials...so instead smtpd + # SimSMTPChannel doesn't fully support AUTH because it requires a + # synchronous read to obtain the credentials...so instead smtpd # sees the credential sent by smtplib's login method as an unknown command, # which results in smtplib raising an auth error. Fortunately the error # message contains the encoded credential, so we can partially check that it # was generated correctly (partially, because the 'word' is uppercased in # the error message). + def testAUTH_PLAIN(self): + self.serv.add_feature("AUTH PLAIN") + smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15) + try: smtp.login(sim_auth[0], sim_auth[1]) + except smtplib.SMTPAuthenticationError as err: + self.assertIn(sim_auth_plain, str(err)) + smtp.close() + def testAUTH_LOGIN(self): self.serv.add_feature("AUTH LOGIN") smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15) try: smtp.login(sim_auth[0], sim_auth[1]) except smtplib.SMTPAuthenticationError as err: - self.assertIn(sim_auth_login_password, str(err)) + self.assertIn(sim_auth_login_user, str(err)) smtp.close() def testAUTH_CRAM_MD5(self): @@ -855,7 +857,23 @@ class SMTPSimTests(unittest.TestCase): smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15) try: smtp.login(sim_auth[0], sim_auth[1]) except smtplib.SMTPAuthenticationError as err: - self.assertIn(sim_auth_login_password, str(err)) + self.assertIn(sim_auth_login_user, str(err)) + smtp.close() + + def test_auth_function(self): + smtp = smtplib.SMTP(HOST, self.port, + local_hostname='localhost', timeout=15) + self.serv.add_feature("AUTH CRAM-MD5") + smtp.user, smtp.password = sim_auth[0], sim_auth[1] + supported = {'CRAM-MD5': smtp.auth_cram_md5, + 'PLAIN': smtp.auth_plain, + 'LOGIN': smtp.auth_login, + } + for mechanism, method in supported.items(): + try: smtp.auth(mechanism, method) + except smtplib.SMTPAuthenticationError as err: + self.assertIn(sim_auth_credentials[mechanism.lower()].upper(), + str(err)) smtp.close() def test_with_statement(self): diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py index b1ce058..0712a4f 100644 --- a/Lib/test/test_socket.py +++ b/Lib/test/test_socket.py @@ -19,6 +19,8 @@ import signal import math import pickle import struct +import random +import string try: import multiprocessing except ImportError: @@ -1344,10 +1346,13 @@ class GeneralModuleTests(unittest.TestCase): def test_listen_backlog(self): for backlog in 0, -1: - srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM) + with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as srv: + srv.bind((HOST, 0)) + srv.listen(backlog) + + with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as srv: srv.bind((HOST, 0)) - srv.listen(backlog) - srv.close() + srv.listen() @support.cpython_only def test_listen_backlog_overflow(self): @@ -5075,6 +5080,275 @@ class TestSocketSharing(SocketTCPTest): source.close() +@unittest.skipUnless(thread, 'Threading required for this test.') +class SendfileUsingSendTest(ThreadedTCPSocketTest): + """ + Test the send() implementation of socket.sendfile(). + """ + + FILESIZE = (10 * 1024 * 1024) # 10MB + BUFSIZE = 8192 + FILEDATA = b"" + TIMEOUT = 2 + + @classmethod + def setUpClass(cls): + def chunks(total, step): + assert total >= step + while total > step: + yield step + total -= step + if total: + yield total + + chunk = b"".join([random.choice(string.ascii_letters).encode() + for i in range(cls.BUFSIZE)]) + with open(support.TESTFN, 'wb') as f: + for csize in chunks(cls.FILESIZE, cls.BUFSIZE): + f.write(chunk) + with open(support.TESTFN, 'rb') as f: + cls.FILEDATA = f.read() + assert len(cls.FILEDATA) == cls.FILESIZE + + @classmethod + def tearDownClass(cls): + support.unlink(support.TESTFN) + + def accept_conn(self): + self.serv.settimeout(self.TIMEOUT) + conn, addr = self.serv.accept() + conn.settimeout(self.TIMEOUT) + self.addCleanup(conn.close) + return conn + + def recv_data(self, conn): + received = [] + while True: + chunk = conn.recv(self.BUFSIZE) + if not chunk: + break + received.append(chunk) + return b''.join(received) + + def meth_from_sock(self, sock): + # Depending on the mixin class being run return either send() + # or sendfile() method implementation. + return getattr(sock, "_sendfile_use_send") + + # regular file + + def _testRegularFile(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address) as sock, file as file: + meth = self.meth_from_sock(sock) + sent = meth(file) + self.assertEqual(sent, self.FILESIZE) + self.assertEqual(file.tell(), self.FILESIZE) + + def testRegularFile(self): + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(len(data), self.FILESIZE) + self.assertEqual(data, self.FILEDATA) + + # non regular file + + def _testNonRegularFile(self): + address = self.serv.getsockname() + file = io.BytesIO(self.FILEDATA) + with socket.create_connection(address) as sock, file as file: + sent = sock.sendfile(file) + self.assertEqual(sent, self.FILESIZE) + self.assertEqual(file.tell(), self.FILESIZE) + self.assertRaises(socket._GiveupOnSendfile, + sock._sendfile_use_sendfile, file) + + def testNonRegularFile(self): + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(len(data), self.FILESIZE) + self.assertEqual(data, self.FILEDATA) + + # empty file + + def _testEmptyFileSend(self): + address = self.serv.getsockname() + filename = support.TESTFN + "2" + with open(filename, 'wb'): + self.addCleanup(support.unlink, filename) + file = open(filename, 'rb') + with socket.create_connection(address) as sock, file as file: + meth = self.meth_from_sock(sock) + sent = meth(file) + self.assertEqual(sent, 0) + self.assertEqual(file.tell(), 0) + + def testEmptyFileSend(self): + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(data, b"") + + # offset + + def _testOffset(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address) as sock, file as file: + meth = self.meth_from_sock(sock) + sent = meth(file, offset=5000) + self.assertEqual(sent, self.FILESIZE - 5000) + self.assertEqual(file.tell(), self.FILESIZE) + + def testOffset(self): + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(len(data), self.FILESIZE - 5000) + self.assertEqual(data, self.FILEDATA[5000:]) + + # count + + def _testCount(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address, timeout=2) as sock, file as file: + count = 5000007 + meth = self.meth_from_sock(sock) + sent = meth(file, count=count) + self.assertEqual(sent, count) + self.assertEqual(file.tell(), count) + + def testCount(self): + count = 5000007 + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(len(data), count) + self.assertEqual(data, self.FILEDATA[:count]) + + # count small + + def _testCountSmall(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address, timeout=2) as sock, file as file: + count = 1 + meth = self.meth_from_sock(sock) + sent = meth(file, count=count) + self.assertEqual(sent, count) + self.assertEqual(file.tell(), count) + + def testCountSmall(self): + count = 1 + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(len(data), count) + self.assertEqual(data, self.FILEDATA[:count]) + + # count + offset + + def _testCountWithOffset(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address, timeout=2) as sock, file as file: + count = 100007 + meth = self.meth_from_sock(sock) + sent = meth(file, offset=2007, count=count) + self.assertEqual(sent, count) + self.assertEqual(file.tell(), count + 2007) + + def testCountWithOffset(self): + count = 100007 + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(len(data), count) + self.assertEqual(data, self.FILEDATA[2007:count+2007]) + + # non blocking sockets are not supposed to work + + def _testNonBlocking(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address) as sock, file as file: + sock.setblocking(False) + meth = self.meth_from_sock(sock) + self.assertRaises(ValueError, meth, file) + self.assertRaises(ValueError, sock.sendfile, file) + + def testNonBlocking(self): + conn = self.accept_conn() + if conn.recv(8192): + self.fail('was not supposed to receive any data') + + # timeout (non-triggered) + + def _testWithTimeout(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address, timeout=2) as sock, file as file: + meth = self.meth_from_sock(sock) + sent = meth(file) + self.assertEqual(sent, self.FILESIZE) + + def testWithTimeout(self): + conn = self.accept_conn() + data = self.recv_data(conn) + self.assertEqual(len(data), self.FILESIZE) + self.assertEqual(data, self.FILEDATA) + + # timeout (triggered) + + def _testWithTimeoutTriggeredSend(self): + address = self.serv.getsockname() + file = open(support.TESTFN, 'rb') + with socket.create_connection(address, timeout=0.01) as sock, \ + file as file: + meth = self.meth_from_sock(sock) + self.assertRaises(socket.timeout, meth, file) + + def testWithTimeoutTriggeredSend(self): + conn = self.accept_conn() + conn.recv(88192) + + # errors + + def _test_errors(self): + pass + + def test_errors(self): + with open(support.TESTFN, 'rb') as file: + with socket.socket(type=socket.SOCK_DGRAM) as s: + meth = self.meth_from_sock(s) + self.assertRaisesRegex( + ValueError, "SOCK_STREAM", meth, file) + with open(support.TESTFN, 'rt') as file: + with socket.socket() as s: + meth = self.meth_from_sock(s) + self.assertRaisesRegex( + ValueError, "binary mode", meth, file) + with open(support.TESTFN, 'rb') as file: + with socket.socket() as s: + meth = self.meth_from_sock(s) + self.assertRaisesRegex(TypeError, "positive integer", + meth, file, count='2') + self.assertRaisesRegex(TypeError, "positive integer", + meth, file, count=0.1) + self.assertRaisesRegex(ValueError, "positive integer", + meth, file, count=0) + self.assertRaisesRegex(ValueError, "positive integer", + meth, file, count=-1) + + +@unittest.skipUnless(thread, 'Threading required for this test.') +@unittest.skipUnless(hasattr(os, "sendfile"), + 'os.sendfile() required for this test.') +class SendfileUsingSendfileTest(SendfileUsingSendTest): + """ + Test the sendfile() implementation of socket.sendfile(). + """ + def meth_from_sock(self, sock): + return getattr(sock, "_sendfile_use_sendfile") + + def test_main(): tests = [GeneralModuleTests, BasicTCPTest, TCPCloserTest, TCPTimeoutTest, TestExceptions, BufferIOTest, BasicTCPTest2, BasicUDPTest, UDPTimeoutTest ] @@ -5127,6 +5401,8 @@ def test_main(): InterruptedRecvTimeoutTest, InterruptedSendTimeoutTest, TestSocketSharing, + SendfileUsingSendTest, + SendfileUsingSendfileTest, ]) thread_info = support.threading_setup() diff --git a/Lib/test/test_socketserver.py b/Lib/test/test_socketserver.py index 0617b30..8e0fde4 100644 --- a/Lib/test/test_socketserver.py +++ b/Lib/test/test_socketserver.py @@ -222,38 +222,6 @@ class SocketServerTest(unittest.TestCase): socketserver.DatagramRequestHandler, self.dgram_examine) - @contextlib.contextmanager - def mocked_select_module(self): - """Mocks the select.select() call to raise EINTR for first call""" - old_select = select.select - - class MockSelect: - def __init__(self): - self.called = 0 - - def __call__(self, *args): - self.called += 1 - if self.called == 1: - # raise the exception on first call - raise OSError(errno.EINTR, os.strerror(errno.EINTR)) - else: - # Return real select value for consecutive calls - return old_select(*args) - - select.select = MockSelect() - try: - yield select.select - finally: - select.select = old_select - - def test_InterruptServerSelectCall(self): - with self.mocked_select_module() as mock_select: - pid = self.run_server(socketserver.TCPServer, - socketserver.StreamRequestHandler, - self.stream_examine) - # Make sure select was called again: - self.assertGreater(mock_select.called, 1) - # Alas, on Linux (at least) recvfrom() doesn't return a meaningful # client address so this cannot work: diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py index 2b3de1f..bdde9ac 100644 --- a/Lib/test/test_ssl.py +++ b/Lib/test/test_ssl.py @@ -86,6 +86,12 @@ def have_verify_flags(): # 0.9.8 or higher return ssl.OPENSSL_VERSION_INFO >= (0, 9, 8, 0, 15) +def utc_offset(): #NOTE: ignore issues like #1647654 + # local time = utc time + utc offset + if time.daylight and time.localtime().tm_isdst > 0: + return -time.altzone # seconds + return -time.timezone + def asn1time(cert_time): # Some versions of OpenSSL ignore seconds, see #18207 # 0.9.8.i @@ -134,6 +140,14 @@ class BasicSocketTests(unittest.TestCase): self.assertIn(ssl.HAS_SNI, {True, False}) self.assertIn(ssl.HAS_ECDH, {True, False}) + def test_str_for_enums(self): + # Make sure that the PROTOCOL_* constants have enum-like string + # reprs. + proto = ssl.PROTOCOL_SSLv3 + self.assertEqual(str(proto), '_SSLMethod.PROTOCOL_SSLv3') + ctx = ssl.SSLContext(proto) + self.assertIs(ctx.protocol, proto) + def test_random(self): v = ssl.RAND_status() if support.verbose: @@ -643,6 +657,71 @@ class BasicSocketTests(unittest.TestCase): ctx.wrap_socket(s) self.assertEqual(str(cx.exception), "only stream sockets are supported") + def cert_time_ok(self, timestring, timestamp): + self.assertEqual(ssl.cert_time_to_seconds(timestring), timestamp) + + def cert_time_fail(self, timestring): + with self.assertRaises(ValueError): + ssl.cert_time_to_seconds(timestring) + + @unittest.skipUnless(utc_offset(), + 'local time needs to be different from UTC') + def test_cert_time_to_seconds_timezone(self): + # Issue #19940: ssl.cert_time_to_seconds() returns wrong + # results if local timezone is not UTC + self.cert_time_ok("May 9 00:00:00 2007 GMT", 1178668800.0) + self.cert_time_ok("Jan 5 09:34:43 2018 GMT", 1515144883.0) + + def test_cert_time_to_seconds(self): + timestring = "Jan 5 09:34:43 2018 GMT" + ts = 1515144883.0 + self.cert_time_ok(timestring, ts) + # accept keyword parameter, assert its name + self.assertEqual(ssl.cert_time_to_seconds(cert_time=timestring), ts) + # accept both %e and %d (space or zero generated by strftime) + self.cert_time_ok("Jan 05 09:34:43 2018 GMT", ts) + # case-insensitive + self.cert_time_ok("JaN 5 09:34:43 2018 GmT", ts) + self.cert_time_fail("Jan 5 09:34 2018 GMT") # no seconds + self.cert_time_fail("Jan 5 09:34:43 2018") # no GMT + self.cert_time_fail("Jan 5 09:34:43 2018 UTC") # not GMT timezone + self.cert_time_fail("Jan 35 09:34:43 2018 GMT") # invalid day + self.cert_time_fail("Jon 5 09:34:43 2018 GMT") # invalid month + self.cert_time_fail("Jan 5 24:00:00 2018 GMT") # invalid hour + self.cert_time_fail("Jan 5 09:60:43 2018 GMT") # invalid minute + + newyear_ts = 1230768000.0 + # leap seconds + self.cert_time_ok("Dec 31 23:59:60 2008 GMT", newyear_ts) + # same timestamp + self.cert_time_ok("Jan 1 00:00:00 2009 GMT", newyear_ts) + + self.cert_time_ok("Jan 5 09:34:59 2018 GMT", 1515144899) + # allow 60th second (even if it is not a leap second) + self.cert_time_ok("Jan 5 09:34:60 2018 GMT", 1515144900) + # allow 2nd leap second for compatibility with time.strptime() + self.cert_time_ok("Jan 5 09:34:61 2018 GMT", 1515144901) + self.cert_time_fail("Jan 5 09:34:62 2018 GMT") # invalid seconds + + # no special treatement for the special value: + # 99991231235959Z (rfc 5280) + self.cert_time_ok("Dec 31 23:59:59 9999 GMT", 253402300799.0) + + @support.run_with_locale('LC_ALL', '') + def test_cert_time_to_seconds_locale(self): + # `cert_time_to_seconds()` should be locale independent + + def local_february_name(): + return time.strftime('%b', (1, 2, 3, 4, 5, 6, 0, 0, 0)) + + if local_february_name().lower() == 'feb': + self.skipTest("locale-specific month name needs to be " + "different from C locale") + + # locale-independent + self.cert_time_ok("Feb 9 00:00:00 2007 GMT", 1170979200.0) + self.cert_time_fail(local_february_name() + " 9 00:00:00 2007 GMT") + class ContextTests(unittest.TestCase): @@ -1371,14 +1450,12 @@ class NetworkedTests(unittest.TestCase): def test_get_server_certificate(self): def _test_get_server_certificate(host, port, cert=None): with support.transient_internet(host): - pem = ssl.get_server_certificate((host, port), - ssl.PROTOCOL_SSLv23) + pem = ssl.get_server_certificate((host, port)) if not pem: self.fail("No server certificate on %s:%s!" % (host, port)) try: pem = ssl.get_server_certificate((host, port), - ssl.PROTOCOL_SSLv23, ca_certs=CERTFILE) except ssl.SSLError as x: #should fail @@ -1388,7 +1465,6 @@ class NetworkedTests(unittest.TestCase): self.fail("Got server certificate %s for %s:%s!" % (pem, host, port)) pem = ssl.get_server_certificate((host, port), - ssl.PROTOCOL_SSLv23, ca_certs=cert) if not pem: self.fail("No server certificate on %s:%s!" % (host, port)) @@ -2471,6 +2547,36 @@ else: s.write(b"over\n") s.close() + def test_nonblocking_send(self): + server = ThreadedEchoServer(CERTFILE, + certreqs=ssl.CERT_NONE, + ssl_version=ssl.PROTOCOL_TLSv1, + cacerts=CERTFILE, + chatty=True, + connectionchatty=False) + with server: + s = ssl.wrap_socket(socket.socket(), + server_side=False, + certfile=CERTFILE, + ca_certs=CERTFILE, + cert_reqs=ssl.CERT_NONE, + ssl_version=ssl.PROTOCOL_TLSv1) + s.connect((HOST, server.port)) + s.setblocking(False) + + # If we keep sending data, at some point the buffers + # will be full and the call will block + buf = bytearray(8192) + def fill_buffer(): + while True: + s.send(buf) + self.assertRaises((ssl.SSLWantWriteError, + ssl.SSLWantReadError), fill_buffer) + + # Now read all the output and discard it + s.setblocking(True) + s.close() + def test_handshake_timeout(self): # Issue #5103: SSL handshake must respect the socket timeout server = socket.socket(socket.AF_INET) @@ -2851,6 +2957,23 @@ else: self.assertRaises(ValueError, s.read, 1024) self.assertRaises(ValueError, s.write, b'hello') + def test_sendfile(self): + TEST_DATA = b"x" * 512 + with open(support.TESTFN, 'wb') as f: + f.write(TEST_DATA) + self.addCleanup(support.unlink, support.TESTFN) + context = ssl.SSLContext(ssl.PROTOCOL_SSLv23) + context.verify_mode = ssl.CERT_REQUIRED + context.load_verify_locations(CERTFILE) + context.load_cert_chain(CERTFILE) + server = ThreadedEchoServer(context=context, chatty=False) + with server: + with context.wrap_socket(socket.socket()) as s: + s.connect((HOST, server.port)) + with open(support.TESTFN, 'rb') as file: + s.sendfile(file) + self.assertEqual(s.recv(1024), TEST_DATA) + def test_main(verbose=False): if support.verbose: diff --git a/Lib/test/test_stat.py b/Lib/test/test_stat.py index af6ced4..f1a5938 100644 --- a/Lib/test/test_stat.py +++ b/Lib/test/test_stat.py @@ -1,5 +1,6 @@ import unittest import os +import sys from test.support import TESTFN, import_fresh_module c_stat = import_fresh_module('stat', fresh=['_stat']) @@ -52,6 +53,26 @@ class TestFilemode: 'S_IWOTH': 0o002, 'S_IXOTH': 0o001} + # defined by the Windows API documentation + file_attributes = { + 'FILE_ATTRIBUTE_ARCHIVE': 32, + 'FILE_ATTRIBUTE_COMPRESSED': 2048, + 'FILE_ATTRIBUTE_DEVICE': 64, + 'FILE_ATTRIBUTE_DIRECTORY': 16, + 'FILE_ATTRIBUTE_ENCRYPTED': 16384, + 'FILE_ATTRIBUTE_HIDDEN': 2, + 'FILE_ATTRIBUTE_INTEGRITY_STREAM': 32768, + 'FILE_ATTRIBUTE_NORMAL': 128, + 'FILE_ATTRIBUTE_NOT_CONTENT_INDEXED': 8192, + 'FILE_ATTRIBUTE_NO_SCRUB_DATA': 131072, + 'FILE_ATTRIBUTE_OFFLINE': 4096, + 'FILE_ATTRIBUTE_READONLY': 1, + 'FILE_ATTRIBUTE_REPARSE_POINT': 1024, + 'FILE_ATTRIBUTE_SPARSE_FILE': 512, + 'FILE_ATTRIBUTE_SYSTEM': 4, + 'FILE_ATTRIBUTE_TEMPORARY': 256, + 'FILE_ATTRIBUTE_VIRTUAL': 65536} + def setUp(self): try: os.remove(TESTFN) @@ -185,6 +206,14 @@ class TestFilemode: self.assertTrue(callable(func)) self.assertEqual(func(0), 0) + @unittest.skipUnless(sys.platform == "win32", + "FILE_ATTRIBUTE_* constants are Win32 specific") + def test_file_attribute_constants(self): + for key, value in sorted(self.file_attributes.items()): + self.assertTrue(hasattr(self.statmod, key), key) + modvalue = getattr(self.statmod, key) + self.assertEqual(value, modvalue, key) + class TestFilemodeCStat(TestFilemode, unittest.TestCase): statmod = c_stat diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py index a68ed08..854e786 100644 --- a/Lib/test/test_sys.py +++ b/Lib/test/test_sys.py @@ -635,6 +635,53 @@ class SysModuleTest(unittest.TestCase): expected = None self.check_fsencoding(fs_encoding, expected) + def c_locale_get_error_handler(self, isolated=False, encoding=None): + # Force the POSIX locale + env = os.environ.copy() + env["LC_ALL"] = "C" + code = '\n'.join(( + 'import sys', + 'def dump(name):', + ' std = getattr(sys, name)', + ' print("%s: %s" % (name, std.errors))', + 'dump("stdin")', + 'dump("stdout")', + 'dump("stderr")', + )) + args = [sys.executable, "-c", code] + if isolated: + args.append("-I") + elif encoding: + env['PYTHONIOENCODING'] = encoding + p = subprocess.Popen(args, + stdout=subprocess.PIPE, + stderr=subprocess.STDOUT, + env=env, + universal_newlines=True) + stdout, stderr = p.communicate() + return stdout + + def test_c_locale_surrogateescape(self): + out = self.c_locale_get_error_handler(isolated=True) + self.assertEqual(out, + 'stdin: surrogateescape\n' + 'stdout: surrogateescape\n' + 'stderr: backslashreplace\n') + + # replace the default error handler + out = self.c_locale_get_error_handler(encoding=':strict') + self.assertEqual(out, + 'stdin: strict\n' + 'stdout: strict\n' + 'stderr: backslashreplace\n') + + # force the encoding + out = self.c_locale_get_error_handler(encoding='iso8859-1') + self.assertEqual(out, + 'stdin: surrogateescape\n' + 'stdout: surrogateescape\n' + 'stderr: backslashreplace\n') + def test_implementation(self): # This test applies to all implementations equally. @@ -838,7 +885,7 @@ class SizeofTest(unittest.TestCase): check(bar, size('PP')) # generator def get_gen(): yield 1 - check(get_gen(), size('Pb2P')) + check(get_gen(), size('Pb2PPP')) # iterator check(iter('abc'), size('lP')) # callable-iterator @@ -925,7 +972,7 @@ class SizeofTest(unittest.TestCase): check(int, s) # (PyTypeObject + PyNumberMethods + PyMappingMethods + # PySequenceMethods + PyBufferProcs + 4P) - s = vsize('P2n15Pl4Pn9Pn11PIP') + struct.calcsize('34P 3P 10P 2P 4P') + s = vsize('P2n17Pl4Pn9Pn11PIP') + struct.calcsize('34P 3P 10P 2P 4P') # Separate block for PyDictKeysObject with 4 entries s += struct.calcsize("2nPn") + 4*struct.calcsize("n2P") # class diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py index 82aa840..e527e40 100644 --- a/Lib/test/test_tarfile.py +++ b/Lib/test/test_tarfile.py @@ -1,7 +1,6 @@ import sys import os import io -import shutil from hashlib import md5 import unittest @@ -480,16 +479,16 @@ class MiscReadTestBase(CommonReadTest): # Test hardlink extraction (e.g. bug #857297). with tarfile.open(tarname, errorlevel=1, encoding="iso8859-1") as tar: tar.extract("ustar/regtype", TEMPDIR) - self.addCleanup(os.remove, os.path.join(TEMPDIR, "ustar/regtype")) + self.addCleanup(support.unlink, os.path.join(TEMPDIR, "ustar/regtype")) tar.extract("ustar/lnktype", TEMPDIR) - self.addCleanup(os.remove, os.path.join(TEMPDIR, "ustar/lnktype")) + self.addCleanup(support.unlink, os.path.join(TEMPDIR, "ustar/lnktype")) with open(os.path.join(TEMPDIR, "ustar/lnktype"), "rb") as f: data = f.read() self.assertEqual(md5sum(data), md5_regtype) tar.extract("ustar/symtype", TEMPDIR) - self.addCleanup(os.remove, os.path.join(TEMPDIR, "ustar/symtype")) + self.addCleanup(support.unlink, os.path.join(TEMPDIR, "ustar/symtype")) with open(os.path.join(TEMPDIR, "ustar/symtype"), "rb") as f: data = f.read() self.assertEqual(md5sum(data), md5_regtype) @@ -522,7 +521,7 @@ class MiscReadTestBase(CommonReadTest): self.assertEqual(tarinfo.mtime, file_mtime, errmsg) finally: tar.close() - shutil.rmtree(DIR) + support.rmtree(DIR) def test_extract_directory(self): dirtype = "ustar/dirtype" @@ -537,7 +536,7 @@ class MiscReadTestBase(CommonReadTest): if sys.platform != "win32": self.assertEqual(os.stat(extracted).st_mode & 0o777, 0o755) finally: - shutil.rmtree(DIR) + support.rmtree(DIR) def test_init_close_fobj(self): # Issue #7341: Close the internal file object in the TarFile @@ -901,7 +900,7 @@ class GNUReadTest(LongnameTest, ReadTest, unittest.TestCase): fobj.seek(4096) fobj.truncate() s = os.stat(name) - os.remove(name) + support.unlink(name) return s.st_blocks == 0 else: return False @@ -1034,7 +1033,7 @@ class WriteTest(WriteTestBase, unittest.TestCase): finally: tar.close() finally: - os.rmdir(path) + support.rmdir(path) @unittest.skipUnless(hasattr(os, "link"), "Missing hardlink implementation") @@ -1054,8 +1053,8 @@ class WriteTest(WriteTestBase, unittest.TestCase): finally: tar.close() finally: - os.remove(target) - os.remove(link) + support.unlink(target) + support.unlink(link) @support.skip_unless_symlink def test_symlink_size(self): @@ -1069,7 +1068,7 @@ class WriteTest(WriteTestBase, unittest.TestCase): finally: tar.close() finally: - os.remove(path) + support.unlink(path) def test_add_self(self): # Test for #1257255. @@ -1116,7 +1115,7 @@ class WriteTest(WriteTestBase, unittest.TestCase): finally: tar.close() finally: - shutil.rmtree(tempdir) + support.rmtree(tempdir) def test_filter(self): tempdir = os.path.join(TEMPDIR, "filter") @@ -1152,7 +1151,7 @@ class WriteTest(WriteTestBase, unittest.TestCase): finally: tar.close() finally: - shutil.rmtree(tempdir) + support.rmtree(tempdir) # Guarantee that stored pathnames are not modified. Don't # remove ./ or ../ or double slashes. Still make absolute @@ -1180,9 +1179,9 @@ class WriteTest(WriteTestBase, unittest.TestCase): tar.close() if not dir: - os.remove(foo) + support.unlink(foo) else: - os.rmdir(foo) + support.rmdir(foo) self.assertEqual(t.name, cmp_path or path.replace(os.sep, "/")) @@ -1213,8 +1212,8 @@ class WriteTest(WriteTestBase, unittest.TestCase): finally: tar.close() finally: - os.unlink(temparchive) - shutil.rmtree(tempdir) + support.unlink(temparchive) + support.rmtree(tempdir) def test_pathnames(self): self._test_pathname("foo") @@ -1314,7 +1313,7 @@ class StreamWriteTest(WriteTestBase, unittest.TestCase): # Test for issue #8464: Create files with correct # permissions. if os.path.exists(tmpname): - os.remove(tmpname) + support.unlink(tmpname) original_umask = os.umask(0o022) try: @@ -1668,7 +1667,7 @@ class AppendTestBase: def setUp(self): self.tarname = tmpname if os.path.exists(self.tarname): - os.remove(self.tarname) + support.unlink(self.tarname) def _create_testtar(self, mode="w:"): with tarfile.open(tarname, encoding="iso8859-1") as src: @@ -2175,7 +2174,7 @@ def setUpModule(): def tearDownModule(): if os.path.exists(TEMPDIR): - shutil.rmtree(TEMPDIR) + support.rmtree(TEMPDIR) if __name__ == "__main__": unittest.main() diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py index 01b532d..5691658 100644 --- a/Lib/test/test_tcl.py +++ b/Lib/test/test_tcl.py @@ -411,6 +411,8 @@ class TclTest(unittest.TestCase): # XXX NaN representation can be not parsable by float() self.assertEqual(passValue((1, '2', (3.4,))), (1, '2', (3.4,)) if self.wantobjects else '1 2 3.4') + self.assertEqual(passValue(['a', ['b', 'c']]), + ('a', ('b', 'c')) if self.wantobjects else 'a {b c}') def test_user_command(self): result = None @@ -455,6 +457,7 @@ class TclTest(unittest.TestCase): # XXX NaN representation can be not parsable by float() check((), '') check((1, (2,), (3, 4), '5 6', ()), '1 2 {3 4} {5 6} {}') + check([1, [2,], [3, 4], '5 6', []], '1 2 {3 4} {5 6} {}') def test_splitlist(self): splitlist = self.interp.tk.splitlist @@ -480,6 +483,8 @@ class TclTest(unittest.TestCase): ('a 3.4', ('a', '3.4')), (('a', 3.4), ('a', 3.4)), ((), ()), + ([], ()), + (['a', ['b', 'c']], ('a', ['b', 'c'])), (call('list', 1, '2', (3.4,)), (1, '2', (3.4,)) if self.wantobjects else ('1', '2', '3.4')), @@ -527,6 +532,9 @@ class TclTest(unittest.TestCase): (('a', 3.4), ('a', 3.4)), (('a', (2, 3.4)), ('a', (2, 3.4))), ((), ()), + ([], ()), + (['a', 'b c'], ('a', ('b', 'c'))), + (['a', ['b', 'c']], ('a', ('b', 'c'))), (call('list', 1, '2', (3.4,)), (1, '2', (3.4,)) if self.wantobjects else ('1', '2', '3.4')), diff --git a/Lib/test/test_tokenize.py b/Lib/test/test_tokenize.py index 38611a7..8f74a06 100644 --- a/Lib/test/test_tokenize.py +++ b/Lib/test/test_tokenize.py @@ -464,7 +464,7 @@ Additive Multiplicative - >>> dump_tokens("x = 1//1*1/5*12%0x12") + >>> dump_tokens("x = 1//1*1/5*12%0x12@42") ENCODING 'utf-8' (0, 0) (0, 0) NAME 'x' (1, 0) (1, 1) OP '=' (1, 2) (1, 3) @@ -479,6 +479,8 @@ Multiplicative NUMBER '12' (1, 13) (1, 15) OP '%' (1, 15) (1, 16) NUMBER '0x12' (1, 16) (1, 20) + OP '@' (1, 20) (1, 21) + NUMBER '42' (1, 21) (1, 23) Unary @@ -1154,6 +1156,7 @@ class TestTokenize(TestCase): self.assertExactTypeEqual('//', token.DOUBLESLASH) self.assertExactTypeEqual('//=', token.DOUBLESLASHEQUAL) self.assertExactTypeEqual('@', token.AT) + self.assertExactTypeEqual('@=', token.ATEQUAL) self.assertExactTypeEqual('a**2+b**2==c**2', NAME, token.DOUBLESTAR, NUMBER, diff --git a/Lib/test/test_trace.py b/Lib/test/test_trace.py index 1cec710..05bf274 100644 --- a/Lib/test/test_trace.py +++ b/Lib/test/test_trace.py @@ -10,7 +10,6 @@ from trace import CoverageResults, Trace from test.tracedmodules import testmod - #------------------------------- Utilities -----------------------------------# def fix_ext_py(filename): @@ -224,6 +223,11 @@ class TestFuncs(unittest.TestCase): self.addCleanup(sys.settrace, sys.gettrace()) self.tracer = Trace(count=0, trace=0, countfuncs=1) self.filemod = my_file_and_modname() + self._saved_tracefunc = sys.gettrace() + + def tearDown(self): + if self._saved_tracefunc is not None: + sys.settrace(self._saved_tracefunc) def test_simple_caller(self): self.tracer.runfunc(traced_func_simple_caller, 1) diff --git a/Lib/test/test_tuple.py b/Lib/test/test_tuple.py index e41711c..14c6430 100644 --- a/Lib/test/test_tuple.py +++ b/Lib/test/test_tuple.py @@ -201,6 +201,14 @@ class TupleTest(seq_tests.CommonTest): with self.assertRaises(TypeError): [3,] + T((1,2)) + def test_lexicographic_ordering(self): + # Issue 21100 + a = self.type2test([1, 2]) + b = self.type2test([1, 2, 0]) + c = self.type2test([1, 3]) + self.assertLess(a, b) + self.assertLess(b, c) + def test_main(): support.run_unittest(TupleTest) diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py index ec10752..11d9546 100644 --- a/Lib/test/test_types.py +++ b/Lib/test/test_types.py @@ -343,6 +343,8 @@ class TypesTests(unittest.TestCase): self.assertRaises(ValueError, 3 .__format__, ",n") # can't have ',' with 'c' self.assertRaises(ValueError, 3 .__format__, ",c") + # can't have '#' with 'c' + self.assertRaises(ValueError, 3 .__format__, "#c") # ensure that only int and float type specifiers work for format_spec in ([chr(x) for x in range(ord('a'), ord('z')+1)] + diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py index 9ae31d1..64e6bf5 100644 --- a/Lib/test/test_unicode.py +++ b/Lib/test/test_unicode.py @@ -8,6 +8,7 @@ Written by Marc-Andre Lemburg (mal@lemburg.com). import _string import codecs import itertools +import operator import struct import sys import unittest @@ -250,6 +251,7 @@ class UnicodeTest(string_tests.CommonTest, {ord('a'): None, ord('b'): ''}) self.checkequalnofix('xyyx', 'xzx', 'translate', {ord('z'): 'yy'}) + # this needs maketrans() self.checkequalnofix('abababc', 'abababc', 'translate', {'b': '<i>'}) @@ -259,6 +261,33 @@ class UnicodeTest(string_tests.CommonTest, tbl = self.type2test.maketrans('abc', 'xyz', 'd') self.checkequalnofix('xyzzy', 'abdcdcbdddd', 'translate', tbl) + # various tests switching from ASCII to latin1 or the opposite; + # same length, remove a letter, or replace with a longer string. + self.assertEqual("[a]".translate(str.maketrans('a', 'X')), + "[X]") + self.assertEqual("[a]".translate(str.maketrans({'a': 'X'})), + "[X]") + self.assertEqual("[a]".translate(str.maketrans({'a': None})), + "[]") + self.assertEqual("[a]".translate(str.maketrans({'a': 'XXX'})), + "[XXX]") + self.assertEqual("[a]".translate(str.maketrans({'a': '\xe9'})), + "[\xe9]") + self.assertEqual("[a]".translate(str.maketrans({'a': '<\xe9>'})), + "[<\xe9>]") + self.assertEqual("[\xe9]".translate(str.maketrans({'\xe9': 'a'})), + "[a]") + self.assertEqual("[\xe9]".translate(str.maketrans({'\xe9': None})), + "[]") + + # invalid Unicode characters + invalid_char = 0x10ffff+1 + for before in "a\xe9\u20ac\U0010ffff": + mapping = str.maketrans({before: invalid_char}) + text = "[%s]" % before + self.assertRaises(ValueError, text.translate, mapping) + + # errors self.assertRaises(TypeError, self.type2test.maketrans) self.assertRaises(ValueError, self.type2test.maketrans, 'abc', 'defg') self.assertRaises(TypeError, self.type2test.maketrans, 2, 'def') @@ -1148,20 +1177,20 @@ class UnicodeTest(string_tests.CommonTest, self.assertEqual('%.2s' % "a\xe9\u20ac", 'a\xe9') #issue 19995 - class PsuedoInt: + class PseudoInt: def __init__(self, value): self.value = int(value) def __int__(self): return self.value def __index__(self): return self.value - class PsuedoFloat: + class PseudoFloat: def __init__(self, value): self.value = float(value) def __int__(self): return int(self.value) - pi = PsuedoFloat(3.1415) - letter_m = PsuedoInt(109) + pi = PseudoFloat(3.1415) + letter_m = PseudoInt(109) self.assertEqual('%x' % 42, '2a') self.assertEqual('%X' % 15, 'F') self.assertEqual('%o' % 9, '11') @@ -1170,11 +1199,11 @@ class UnicodeTest(string_tests.CommonTest, self.assertEqual('%X' % letter_m, '6D') self.assertEqual('%o' % letter_m, '155') self.assertEqual('%c' % letter_m, 'm') - self.assertWarns(DeprecationWarning, '%x'.__mod__, pi), - self.assertWarns(DeprecationWarning, '%x'.__mod__, 3.14), - self.assertWarns(DeprecationWarning, '%X'.__mod__, 2.11), - self.assertWarns(DeprecationWarning, '%o'.__mod__, 1.79), - self.assertWarns(DeprecationWarning, '%c'.__mod__, pi), + self.assertRaisesRegex(TypeError, '%x format: an integer is required, not float', operator.mod, '%x', 3.14), + self.assertRaisesRegex(TypeError, '%X format: an integer is required, not float', operator.mod, '%X', 2.11), + self.assertRaisesRegex(TypeError, '%o format: an integer is required, not float', operator.mod, '%o', 1.79), + self.assertRaisesRegex(TypeError, '%x format: an integer is required, not PseudoFloat', operator.mod, '%x', pi), + self.assertRaises(TypeError, operator.mod, '%c', pi), def test_formatting_with_enum(self): # issue18780 diff --git a/Lib/test/test_unicodedata.py b/Lib/test/test_unicodedata.py index 707b30e..f8788a0 100644 --- a/Lib/test/test_unicodedata.py +++ b/Lib/test/test_unicodedata.py @@ -21,7 +21,7 @@ errors = 'surrogatepass' class UnicodeMethodsTest(unittest.TestCase): # update this, if the database changes - expectedchecksum = 'e74e878de71b6e780ffac271785c3cb58f6251f3' + expectedchecksum = '618e2c1a22ee79d2235319709f16c50f987ee21f' def test_method_checksum(self): h = hashlib.sha1() @@ -79,8 +79,9 @@ class UnicodeDatabaseTest(unittest.TestCase): class UnicodeFunctionsTest(UnicodeDatabaseTest): - # update this, if the database changes - expectedchecksum = 'f0b74d26776331cc7bdc3a4698f037d73f2cee2b' + # Update this if the database changes. Make sure to do a full rebuild + # (e.g. 'make distclean && make') to get the correct checksum. + expectedchecksum = '585302895deead0c1c8478c51da9241d4efedca9' def test_function_checksum(self): data = [] h = hashlib.sha1() diff --git a/Lib/test/test_urllibnet.py b/Lib/test/test_urllibnet.py index 4c8ba2d..42ebb6e 100644 --- a/Lib/test/test_urllibnet.py +++ b/Lib/test/test_urllibnet.py @@ -91,7 +91,8 @@ class urlopenNetworkTests(unittest.TestCase): # test getcode() with the fancy opener to get 404 error codes URL = "http://www.example.com/XXXinvalidXXX" with support.transient_internet(URL): - open_url = urllib.request.FancyURLopener().open(URL) + with self.assertWarns(DeprecationWarning): + open_url = urllib.request.FancyURLopener().open(URL) try: code = open_url.getcode() finally: diff --git a/Lib/test/test_wait3.py b/Lib/test/test_wait3.py index f6a065d..bb71481 100644 --- a/Lib/test/test_wait3.py +++ b/Lib/test/test_wait3.py @@ -18,7 +18,8 @@ class Wait3Test(ForkWait): # This many iterations can be required, since some previously run # tests (e.g. test_ctypes) could have spawned a lot of children # very quickly. - for i in range(30): + deadline = time.monotonic() + 10.0 + while time.monotonic() <= deadline: # wait3() shouldn't hang, but some of the buildbots seem to hang # in the forking tests. This is an attempt to fix the problem. spid, status, rusage = os.wait3(os.WNOHANG) diff --git a/Lib/test/test_wait4.py b/Lib/test/test_wait4.py index 352c11a..b427a9b 100644 --- a/Lib/test/test_wait4.py +++ b/Lib/test/test_wait4.py @@ -19,13 +19,14 @@ class Wait4Test(ForkWait): # Issue #11185: wait4 is broken on AIX and will always return 0 # with WNOHANG. option = 0 - for i in range(10): + deadline = time.monotonic() + 10.0 + while time.monotonic() <= deadline: # wait4() shouldn't hang, but some of the buildbots seem to hang # in the forking tests. This is an attempt to fix the problem. spid, status, rusage = os.wait4(cpid, option) if spid == cpid: break - time.sleep(1.0) + time.sleep(0.1) self.assertEqual(spid, cpid) self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8)) self.assertTrue(rusage) diff --git a/Lib/test/test_warnings.py b/Lib/test/test_warnings.py index eec2c24..cd3288b 100644 --- a/Lib/test/test_warnings.py +++ b/Lib/test/test_warnings.py @@ -5,7 +5,7 @@ from io import StringIO import sys import unittest from test import support -from test.script_helper import assert_python_ok +from test.script_helper import assert_python_ok, assert_python_failure from test import warning_tests @@ -370,6 +370,41 @@ class WarnTests(BaseTest): with self.assertRaises(ValueError): self.module.warn(BadStrWarning()) + def test_warning_classes(self): + class MyWarningClass(Warning): + pass + + class NonWarningSubclass: + pass + + # passing a non-subclass of Warning should raise a TypeError + with self.assertRaises(TypeError) as cm: + self.module.warn('bad warning category', '') + self.assertIn('category must be a Warning subclass, not ', + str(cm.exception)) + + with self.assertRaises(TypeError) as cm: + self.module.warn('bad warning category', NonWarningSubclass) + self.assertIn('category must be a Warning subclass, not ', + str(cm.exception)) + + # check that warning instances also raise a TypeError + with self.assertRaises(TypeError) as cm: + self.module.warn('bad warning category', MyWarningClass()) + self.assertIn('category must be a Warning subclass, not ', + str(cm.exception)) + + with self.assertWarns(MyWarningClass) as cm: + self.module.warn('good warning category', MyWarningClass) + self.assertEqual('good warning category', str(cm.warning)) + + with self.assertWarns(UserWarning) as cm: + self.module.warn('good warning category', None) + self.assertEqual('good warning category', str(cm.warning)) + + with self.assertWarns(MyWarningClass) as cm: + self.module.warn('good warning category', MyWarningClass) + self.assertIsInstance(cm.warning, Warning) class CWarnTests(WarnTests, unittest.TestCase): module = c_warnings @@ -748,7 +783,19 @@ class EnvironmentVariableTests(BaseTest): "import sys; sys.stdout.write(str(sys.warnoptions))", PYTHONWARNINGS="ignore::DeprecationWarning") self.assertEqual(stdout, - b"['ignore::UnicodeWarning', 'ignore::DeprecationWarning']") + b"['ignore::DeprecationWarning', 'ignore::UnicodeWarning']") + + def test_conflicting_envvar_and_command_line(self): + rc, stdout, stderr = assert_python_failure("-Werror::DeprecationWarning", "-c", + "import sys, warnings; sys.stdout.write(str(sys.warnoptions)); " + "warnings.warn('Message', DeprecationWarning)", + PYTHONWARNINGS="default::DeprecationWarning") + self.assertEqual(stdout, + b"['default::DeprecationWarning', 'error::DeprecationWarning']") + self.assertEqual(stderr.splitlines(), + [b"Traceback (most recent call last):", + b" File \"<string>\", line 1, in <module>", + b"DeprecationWarning: Message"]) @unittest.skipUnless(sys.getfilesystemencoding() != 'ascii', 'requires non-ascii filesystemencoding') diff --git a/Lib/test/test_wsgiref.py b/Lib/test/test_wsgiref.py index 901f3c9..190f3ba 100644 --- a/Lib/test/test_wsgiref.py +++ b/Lib/test/test_wsgiref.py @@ -338,6 +338,7 @@ class HeaderTests(TestCase): def testMappingInterface(self): test = [('x','y')] + self.assertEqual(len(Headers()), 0) self.assertEqual(len(Headers([])),0) self.assertEqual(len(Headers(test[:])),1) self.assertEqual(Headers(test[:]).keys(), ['x']) @@ -345,7 +346,7 @@ class HeaderTests(TestCase): self.assertEqual(Headers(test[:]).items(), test) self.assertIsNot(Headers(test).items(), test) # must be copy! - h=Headers([]) + h = Headers() del h['foo'] # should not raise an error h['Foo'] = 'bar' @@ -370,9 +371,8 @@ class HeaderTests(TestCase): def testRequireList(self): self.assertRaises(TypeError, Headers, "foo") - def testExtras(self): - h = Headers([]) + h = Headers() self.assertEqual(str(h),'\r\n') h.add_header('foo','bar',baz="spam") diff --git a/Lib/test/test_xmlrpc.py b/Lib/test/test_xmlrpc.py index 99b3eda..120c54f 100644 --- a/Lib/test/test_xmlrpc.py +++ b/Lib/test/test_xmlrpc.py @@ -713,6 +713,23 @@ class SimpleServerTestCase(BaseServerTestCase): conn.request('POST', '/RPC2 HTTP/1.0\r\nContent-Length: 100\r\n\r\nbye') conn.close() + def test_context_manager(self): + with xmlrpclib.ServerProxy(URL) as server: + server.add(2, 3) + self.assertNotEqual(server('transport')._connection, + (None, None)) + self.assertEqual(server('transport')._connection, + (None, None)) + + def test_context_manager_method_error(self): + try: + with xmlrpclib.ServerProxy(URL) as server: + server.add(2, "a") + except xmlrpclib.Fault: + pass + self.assertEqual(server('transport')._connection, + (None, None)) + class MultiPathServerTestCase(BaseServerTestCase): threadFunc = staticmethod(http_multi_server) @@ -898,6 +915,7 @@ class ServerProxyTestCase(unittest.TestCase): p = xmlrpclib.ServerProxy(self.url, transport=t) self.assertEqual(p('transport'), t) + # This is a contrived way to make a failure occur on the server side # in order to test the _send_traceback_header flag on the server class FailingMessageClass(http.client.HTTPMessage): diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py index 0ee75ad..9b428e9 100644 --- a/Lib/test/test_zipfile.py +++ b/Lib/test/test_zipfile.py @@ -3,7 +3,6 @@ import os import sys import importlib.util import time -import shutil import struct import zipfile import unittest @@ -12,7 +11,7 @@ import unittest from tempfile import TemporaryFile from random import randint, random, getrandbits -from test.support import (TESTFN, findfile, unlink, +from test.support import (TESTFN, findfile, unlink, rmtree, requires_zlib, requires_bz2, requires_lzma, captured_stdout, check_warnings) @@ -691,7 +690,7 @@ class PyZipFileTests(unittest.TestCase): self.assertNotIn('mod2.txt', names) finally: - shutil.rmtree(TESTFN2) + rmtree(TESTFN2) def test_write_python_directory_filtered(self): os.mkdir(TESTFN2) @@ -711,7 +710,7 @@ class PyZipFileTests(unittest.TestCase): self.assertNotIn('mod2.py', names) finally: - shutil.rmtree(TESTFN2) + rmtree(TESTFN2) def test_write_non_pyfile(self): with TemporaryFile() as t, zipfile.PyZipFile(t, "w") as zipfp: @@ -741,7 +740,7 @@ class PyZipFileTests(unittest.TestCase): self.assertNotIn('mod1.pyo', names) finally: - shutil.rmtree(TESTFN2) + rmtree(TESTFN2) class ExtractTests(unittest.TestCase): @@ -767,7 +766,7 @@ class ExtractTests(unittest.TestCase): os.remove(writtenfile) # remove the test file subdirectories - shutil.rmtree(os.path.join(os.getcwd(), 'ziptest2dir')) + rmtree(os.path.join(os.getcwd(), 'ziptest2dir')) def test_extract_all(self): with zipfile.ZipFile(TESTFN2, "w", zipfile.ZIP_STORED) as zipfp: @@ -785,7 +784,7 @@ class ExtractTests(unittest.TestCase): os.remove(outfile) # remove the test file subdirectories - shutil.rmtree(os.path.join(os.getcwd(), 'ziptest2dir')) + rmtree(os.path.join(os.getcwd(), 'ziptest2dir')) def check_file(self, filename, content): self.assertTrue(os.path.isfile(filename)) @@ -867,12 +866,12 @@ class ExtractTests(unittest.TestCase): msg='extract %r: %r != %r' % (arcname, writtenfile, correctfile)) self.check_file(correctfile, content) - shutil.rmtree('target') + rmtree('target') with zipfile.ZipFile(TESTFN2, 'r') as zipfp: zipfp.extractall(targetpath) self.check_file(correctfile, content) - shutil.rmtree('target') + rmtree('target') correctfile = os.path.join(os.getcwd(), *fixedname.split('/')) @@ -881,12 +880,12 @@ class ExtractTests(unittest.TestCase): self.assertEqual(writtenfile, correctfile, msg="extract %r" % arcname) self.check_file(correctfile, content) - shutil.rmtree(fixedname.split('/')[0]) + rmtree(fixedname.split('/')[0]) with zipfile.ZipFile(TESTFN2, 'r') as zipfp: zipfp.extractall() self.check_file(correctfile, content) - shutil.rmtree(fixedname.split('/')[0]) + rmtree(fixedname.split('/')[0]) os.remove(TESTFN2) @@ -1643,7 +1642,7 @@ class TestWithDirectory(unittest.TestCase): self.assertTrue(zipf.filelist[0].filename.endswith("x/")) def tearDown(self): - shutil.rmtree(TESTFN2) + rmtree(TESTFN2) if os.path.exists(TESTFN): unlink(TESTFN) diff --git a/Lib/threading.py b/Lib/threading.py index 3407083..c7c4478 100644 --- a/Lib/threading.py +++ b/Lib/threading.py @@ -106,8 +106,14 @@ class _RLock: owner = _active[owner].name except KeyError: pass - return "<%s owner=%r count=%d>" % ( - self.__class__.__name__, owner, self._count) + return "<%s %s.%s object owner=%r count=%d at %s>" % ( + "locked" if self._block.locked() else "unlocked", + self.__class__.__module__, + self.__class__.__qualname__, + owner, + self._count, + hex(id(self)) + ) def acquire(self, blocking=True, timeout=-1): """Acquire a lock, blocking or non-blocking. diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py index 10ac188..d37c39f 100644 --- a/Lib/tkinter/__init__.py +++ b/Lib/tkinter/__init__.py @@ -1280,6 +1280,11 @@ class Misc: def __str__(self): """Return the window path name of this widget.""" return self._w + + def __repr__(self): + return '<%s.%s object %s>' % ( + self.__class__.__module__, self.__class__.__qualname__, self._w) + # Pack methods that apply to the master _noarg_ = ['_noarg_'] def pack_propagate(self, flag=_noarg_): diff --git a/Lib/tkinter/test/test_tkinter/test_misc.py b/Lib/tkinter/test/test_tkinter/test_misc.py index d325b31..46f5170 100644 --- a/Lib/tkinter/test/test_tkinter/test_misc.py +++ b/Lib/tkinter/test/test_tkinter/test_misc.py @@ -10,6 +10,11 @@ class MiscTest(unittest.TestCase): def setUp(self): self.root = ttk.setup_master() + def test_repr(self): + t = tkinter.Toplevel(self.root, name='top') + f = tkinter.Frame(t, name='child') + self.assertEqual(repr(f), '<tkinter.Frame object .top.child>') + def test_tk_setPalette(self): root = self.root root.tk_setPalette('black') diff --git a/Lib/token.py b/Lib/token.py index 7470c8c..bdfcec8 100644 --- a/Lib/token.py +++ b/Lib/token.py @@ -60,11 +60,12 @@ DOUBLESTAREQUAL = 46 DOUBLESLASH = 47 DOUBLESLASHEQUAL = 48 AT = 49 -RARROW = 50 -ELLIPSIS = 51 -OP = 52 -ERRORTOKEN = 53 -N_TOKENS = 54 +ATEQUAL = 50 +RARROW = 51 +ELLIPSIS = 52 +OP = 53 +ERRORTOKEN = 54 +N_TOKENS = 55 NT_OFFSET = 256 #--end constants-- diff --git a/Lib/tokenize.py b/Lib/tokenize.py index 98e9122..742abd1 100644 --- a/Lib/tokenize.py +++ b/Lib/tokenize.py @@ -91,7 +91,8 @@ EXACT_TOKEN_TYPES = { '**=': DOUBLESTAREQUAL, '//': DOUBLESLASH, '//=': DOUBLESLASHEQUAL, - '@': AT + '@': AT, + '@=': ATEQUAL, } class TokenInfo(collections.namedtuple('TokenInfo', 'type string start end line')): @@ -150,7 +151,7 @@ String = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*'", # recognized as two instances of =). Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"!=", r"//=?", r"->", - r"[+\-*/%&|^=<>]=?", + r"[+\-*/%&@|^=<>]=?", r"~") Bracket = '[][(){}]' diff --git a/Lib/trace.py b/Lib/trace.py index 09fe9ee..1c888ac 100755 --- a/Lib/trace.py +++ b/Lib/trace.py @@ -326,16 +326,17 @@ class CoverageResults: lnotab = _find_executable_linenos(filename) else: lnotab = {} + if lnotab: + source = linecache.getlines(filename) + coverpath = os.path.join(dir, modulename + ".cover") + with open(filename, 'rb') as fp: + encoding, _ = tokenize.detect_encoding(fp.readline) + n_hits, n_lines = self.write_results_file(coverpath, source, + lnotab, count, encoding) + if summary and n_lines: + percent = int(100 * n_hits / n_lines) + sums[modulename] = n_lines, percent, modulename, filename - source = linecache.getlines(filename) - coverpath = os.path.join(dir, modulename + ".cover") - with open(filename, 'rb') as fp: - encoding, _ = tokenize.detect_encoding(fp.readline) - n_hits, n_lines = self.write_results_file(coverpath, source, - lnotab, count, encoding) - if summary and n_lines: - percent = int(100 * n_hits / n_lines) - sums[modulename] = n_lines, percent, modulename, filename if summary and sums: print("lines cov% module (path)") diff --git a/Lib/turtledemo/__init__.py b/Lib/turtledemo/__init__.py index e69de29..77150e2 100644 --- a/Lib/turtledemo/__init__.py +++ b/Lib/turtledemo/__init__.py @@ -0,0 +1,14 @@ +""" + -------------------------------------- + About this viewer + -------------------------------------- + + Tiny demo viewer to view turtle graphics example scripts. + + Quickly and dirtyly assembled by Gregor Lingl. + June, 2006 + + For more information see: turtledemo - Help + + Have fun! +""" diff --git a/Lib/turtledemo/__main__.py b/Lib/turtledemo/__main__.py index a14684c..958c283 100755 --- a/Lib/turtledemo/__main__.py +++ b/Lib/turtledemo/__main__.py @@ -1,12 +1,81 @@ #!/usr/bin/env python3 + +""" + ---------------------------------------------- + + turtledemo - Help + + ---------------------------------------------- + + This document has two sections: + + (1) How to use the demo viewer + (2) How to add your own demos to the demo repository + + + (1) How to use the demo viewer. + + Select a demoscript from the example menu. + The (syntax coloured) source code appears in the left + source code window. IT CANNOT BE EDITED, but ONLY VIEWED! + + - Press START button to start the demo. + - Stop execution by pressing the STOP button. + - Clear screen by pressing the CLEAR button. + - Restart by pressing the START button again. + + SPECIAL demos are those which run EVENTDRIVEN. + (For example clock.py - or oldTurtleDemo.py which + in the end expects a mouse click.): + + Press START button to start the demo. + + - Until the EVENTLOOP is entered everything works + as in an ordinary demo script. + + - When the EVENTLOOP is entered, you control the + application by using the mouse and/or keys (or it's + controlled by some timer events) + To stop it you can and must press the STOP button. + + While the EVENTLOOP is running, the examples menu is disabled. + + - Only after having pressed the STOP button, you may + restart it or choose another example script. + + * * * * * * * * + In some rare situations there may occur interferences/conflicts + between events concerning the demo script and those concerning the + demo-viewer. (They run in the same process.) Strange behaviour may be + the consequence and in the worst case you must close and restart the + viewer. + * * * * * * * * + + + (2) How to add your own demos to the demo repository + + - place: same directory as turtledemo/__main__.py + + - requirements on source code: + code must contain a main() function which will + be executed by the viewer (see provided example scripts) + main() may return a string which will be displayed + in the Label below the source code window (when execution + has finished.) + + !! For programs, which are EVENT DRIVEN, main must return + !! the string "EVENTLOOP". This informs the viewer, that the + !! script is still running and must be stopped by the user! +""" import sys import os from tkinter import * from idlelib.Percolator import Percolator from idlelib.ColorDelegator import ColorDelegator -from idlelib.textView import view_file # TextViewer +from idlelib.textView import view_text # TextViewer from importlib import reload +from turtledemo import __doc__ as about_turtledemo import turtle import time @@ -28,16 +97,13 @@ def getExampleEntries(): entry.endswith(".py") and entry[0] != '_'] def showDemoHelp(): - view_file(demo.root, "Help on turtleDemo", - os.path.join(demo_dir, "demohelp.txt")) + view_text(demo.root, "Help on turtledemo", __doc__) def showAboutDemo(): - view_file(demo.root, "About turtleDemo", - os.path.join(demo_dir, "about_turtledemo.txt")) + view_text(demo.root, "About turtledemo", about_turtledemo) def showAboutTurtle(): - view_file(demo.root, "About the new turtle module.", - os.path.join(demo_dir, "about_turtle.txt")) + view_text(demo.root, "About the turtle module.", turtle.__doc__) class DemoWindow(object): diff --git a/Lib/turtledemo/about_turtle.txt b/Lib/turtledemo/about_turtle.txt deleted file mode 100644 index d02c7b3..0000000 --- a/Lib/turtledemo/about_turtle.txt +++ /dev/null @@ -1,76 +0,0 @@ - -======================================================== - A new turtle module for Python -======================================================== - -Turtle graphics is a popular way for introducing programming to -kids. It was part of the original Logo programming language developed -by Wally Feurzig and Seymour Papert in 1966. - -Imagine a robotic turtle starting at (0, 0) in the x-y plane. After an ``import turtle``, give it -the command turtle.forward(15), and it moves (on-screen!) 15 pixels in -the direction it is facing, drawing a line as it moves. Give it the -command turtle.right(25), and it rotates in-place 25 degrees clockwise. - -By combining together these and similar commands, intricate shapes and -pictures can easily be drawn. - ------ turtle.py - -This module is an extended reimplementation of turtle.py from the -Python standard distribution up to Python 2.5. (See: http:\\www.python.org) - -It tries to keep the merits of turtle.py and to be (nearly) 100% -compatible with it. This means in the first place to enable the -learning programmer to use all the commands, classes and methods -interactively when using the module from within IDLE run with -the -n switch. - -Roughly it has the following features added: - -- Better animation of the turtle movements, especially of turning the - turtle. So the turtles can more easily be used as a visual feedback - instrument by the (beginning) programmer. - -- Different turtle shapes, gif-images as turtle shapes, user defined - and user controllable turtle shapes, among them compound - (multicolored) shapes. Turtle shapes can be stgretched and tilted, which - makes turtles zu very versatile geometrical objects. - -- Fine control over turtle movement and screen updates via delay(), - and enhanced tracer() and speed() methods. - -- Aliases for the most commonly used commands, like fd for forward etc., - following the early Logo traditions. This reduces the boring work of - typing long sequences of commands, which often occur in a natural way - when kids try to program fancy pictures on their first encounter with - turtle graphcis. - -- Turtles now have an undo()-method with configurable undo-buffer. - -- Some simple commands/methods for creating event driven programs - (mouse-, key-, timer-events). Especially useful for programming games. - -- A scrollable Canvas class. The default scrollable Canvas can be - extended interactively as needed while playing around with the turtle(s). - -- A TurtleScreen class with methods controlling background color or - background image, window and canvas size and other properties of the - TurtleScreen. - -- There is a method, setworldcoordinates(), to install a user defined - coordinate-system for the TurtleScreen. - -- The implementation uses a 2-vector class named Vec2D, derived from tuple. - This class is public, so it can be imported by the application programmer, - which makes certain types of computations very natural and compact. - -- Appearance of the TurtleScreen and the Turtles at startup/import can be - configured by means of a turtle.cfg configuration file. - The default configuration mimics the appearance of the old turtle module. - -- If configured appropriately the module reads in docstrings from a docstring - dictionary in some different language, supplied separately and replaces - the english ones by those read in. There is a utility function - write_docstringdict() to write a dictionary with the original (english) - docstrings to disc, so it can serve as a template for translations. diff --git a/Lib/turtledemo/about_turtledemo.txt b/Lib/turtledemo/about_turtledemo.txt deleted file mode 100644 index a9009bd..0000000 --- a/Lib/turtledemo/about_turtledemo.txt +++ /dev/null @@ -1,13 +0,0 @@ - - -------------------------------------- - About this viewer - -------------------------------------- - - Tiny demo viewer to view turtle graphics example scripts. - - Quickly and dirtyly assembled by Gregor Lingl. - June, 2006 - - For more information see: turtleDemo - Help - - Have fun! diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py index 5555774..d001976 100644 --- a/Lib/unittest/mock.py +++ b/Lib/unittest/mock.py @@ -27,9 +27,13 @@ __version__ = '1.0' import inspect import pprint import sys +import builtins +from types import ModuleType from functools import wraps, partial +_builtins = {name for name in dir(builtins) if not name.startswith('_')} + BaseExceptions = (BaseException,) if 'java' in sys.platform: # jython @@ -375,7 +379,7 @@ class NonCallableMock(Base): def __init__( self, spec=None, wraps=None, name=None, spec_set=None, parent=None, _spec_state=None, _new_name='', _new_parent=None, - _spec_as_instance=False, _eat_self=None, **kwargs + _spec_as_instance=False, _eat_self=None, unsafe=False, **kwargs ): if _new_parent is None: _new_parent = parent @@ -405,6 +409,7 @@ class NonCallableMock(Base): __dict__['_mock_mock_calls'] = _CallList() __dict__['method_calls'] = _CallList() + __dict__['_mock_unsafe'] = unsafe if kwargs: self.configure_mock(**kwargs) @@ -561,13 +566,16 @@ class NonCallableMock(Base): def __getattr__(self, name): - if name == '_mock_methods': + if name in {'_mock_methods', '_mock_unsafe'}: raise AttributeError(name) elif self._mock_methods is not None: if name not in self._mock_methods or name in _all_magics: raise AttributeError("Mock object has no attribute %r" % name) elif _is_magic(name): raise AttributeError(name) + if not self._mock_unsafe: + if name.startswith(('assert', 'assret')): + raise AttributeError(name) result = self._mock_children.get(name) if result is _deleted: @@ -750,6 +758,14 @@ class NonCallableMock(Base): else: return _call + def assert_not_called(_mock_self): + """assert that the mock was never called. + """ + self = _mock_self + if self.call_count != 0: + msg = ("Expected '%s' to not have been called. Called %s times." % + (self._mock_name or 'mock', self.call_count)) + raise AssertionError(msg) def assert_called_with(_mock_self, *args, **kwargs): """assert that the mock was called with the specified arguments. @@ -1166,6 +1182,9 @@ class _patch(object): else: local = True + if name in _builtins and isinstance(target, ModuleType): + self.create = True + if not self.create and original is DEFAULT: raise AttributeError( "%s does not have the attribute %r" % (target, name) @@ -1875,7 +1894,7 @@ def _format_call_signature(name, args, kwargs): formatted_args = '' args_string = ', '.join([repr(arg) for arg in args]) kwargs_string = ', '.join([ - '%s=%r' % (key, value) for key, value in kwargs.items() + '%s=%r' % (key, value) for key, value in sorted(kwargs.items()) ]) if args_string: formatted_args = args_string diff --git a/Lib/unittest/test/test_case.py b/Lib/unittest/test/test_case.py index 4932578..aae7ec3 100644 --- a/Lib/unittest/test/test_case.py +++ b/Lib/unittest/test/test_case.py @@ -1080,7 +1080,7 @@ test case # so can't use assertEqual either. Just use assertTrue. self.assertTrue(sample_text_error == error) - def testAsertEqualSingleLine(self): + def testAssertEqualSingleLine(self): sample_text = "laden swallows fly slowly" revised_sample_text = "unladen swallows fly quickly" sample_text_error = """\ diff --git a/Lib/unittest/test/test_loader.py b/Lib/unittest/test/test_loader.py index b62a1b5..3e013af 100644 --- a/Lib/unittest/test/test_loader.py +++ b/Lib/unittest/test/test_loader.py @@ -255,7 +255,7 @@ class Test_TestLoader(unittest.TestCase): try: loader.loadTestsFromName('unittest.sdasfasfasdf') except AttributeError as e: - self.assertEqual(str(e), "'module' object has no attribute 'sdasfasfasdf'") + self.assertEqual(str(e), "module 'unittest' has no attribute 'sdasfasfasdf'") else: self.fail("TestLoader.loadTestsFromName failed to raise AttributeError") @@ -272,7 +272,7 @@ class Test_TestLoader(unittest.TestCase): try: loader.loadTestsFromName('sdasfasfasdf', unittest) except AttributeError as e: - self.assertEqual(str(e), "'module' object has no attribute 'sdasfasfasdf'") + self.assertEqual(str(e), "module 'unittest' has no attribute 'sdasfasfasdf'") else: self.fail("TestLoader.loadTestsFromName failed to raise AttributeError") @@ -635,7 +635,7 @@ class Test_TestLoader(unittest.TestCase): try: loader.loadTestsFromNames(['unittest.sdasfasfasdf', 'unittest']) except AttributeError as e: - self.assertEqual(str(e), "'module' object has no attribute 'sdasfasfasdf'") + self.assertEqual(str(e), "module 'unittest' has no attribute 'sdasfasfasdf'") else: self.fail("TestLoader.loadTestsFromNames failed to raise AttributeError") @@ -654,7 +654,7 @@ class Test_TestLoader(unittest.TestCase): try: loader.loadTestsFromNames(['sdasfasfasdf'], unittest) except AttributeError as e: - self.assertEqual(str(e), "'module' object has no attribute 'sdasfasfasdf'") + self.assertEqual(str(e), "module 'unittest' has no attribute 'sdasfasfasdf'") else: self.fail("TestLoader.loadTestsFromName failed to raise AttributeError") @@ -673,7 +673,7 @@ class Test_TestLoader(unittest.TestCase): try: loader.loadTestsFromNames(['TestCase', 'sdasfasfasdf'], unittest) except AttributeError as e: - self.assertEqual(str(e), "'module' object has no attribute 'sdasfasfasdf'") + self.assertEqual(str(e), "module 'unittest' has no attribute 'sdasfasfasdf'") else: self.fail("TestLoader.loadTestsFromName failed to raise AttributeError") diff --git a/Lib/unittest/test/testmock/testmock.py b/Lib/unittest/test/testmock/testmock.py index 23675b9..a549973 100644 --- a/Lib/unittest/test/testmock/testmock.py +++ b/Lib/unittest/test/testmock/testmock.py @@ -1187,6 +1187,32 @@ class MockTest(unittest.TestCase): m = mock.create_autospec(object(), name='sweet_func') self.assertIn('sweet_func', repr(m)) + #Issue21238 + def test_mock_unsafe(self): + m = Mock() + with self.assertRaises(AttributeError): + m.assert_foo_call() + with self.assertRaises(AttributeError): + m.assret_foo_call() + m = Mock(unsafe=True) + m.assert_foo_call() + m.assret_foo_call() + + #Issue21262 + def test_assert_not_called(self): + m = Mock() + m.hello.assert_not_called() + m.hello() + with self.assertRaises(AssertionError): + m.hello.assert_not_called() + + #Issue21256 printout of keyword args should be in deterministic order + def test_sorted_call_signature(self): + m = Mock() + m.hello(name='hello', daddy='hero') + text = "call(daddy='hero', name='hello')" + self.assertEqual(repr(m.hello.call_args), text) + def test_mock_add_spec(self): class _One(object): one = 1 diff --git a/Lib/unittest/test/testmock/testpatch.py b/Lib/unittest/test/testmock/testpatch.py index b516f42..28fe86b 100644 --- a/Lib/unittest/test/testmock/testpatch.py +++ b/Lib/unittest/test/testmock/testpatch.py @@ -377,7 +377,7 @@ class PatchTest(unittest.TestCase): def test_patchobject_wont_create_by_default(self): try: - @patch.object(SomeClass, 'frooble', sentinel.Frooble) + @patch.object(SomeClass, 'ord', sentinel.Frooble) def test(): self.fail('Patching non existent attributes should fail') @@ -386,7 +386,27 @@ class PatchTest(unittest.TestCase): pass else: self.fail('Patching non existent attributes should fail') - self.assertFalse(hasattr(SomeClass, 'frooble')) + self.assertFalse(hasattr(SomeClass, 'ord')) + + + def test_patch_builtins_without_create(self): + @patch(__name__+'.ord') + def test_ord(mock_ord): + mock_ord.return_value = 101 + return ord('c') + + @patch(__name__+'.open') + def test_open(mock_open): + m = mock_open.return_value + m.read.return_value = 'abcd' + + fobj = open('doesnotexists.txt') + data = fobj.read() + fobj.close() + return data + + self.assertEqual(test_ord(), 101) + self.assertEqual(test_open(), 'abcd') def test_patch_with_static_methods(self): diff --git a/Lib/urllib/robotparser.py b/Lib/urllib/robotparser.py index 1d7b751..4fbb0cb 100644 --- a/Lib/urllib/robotparser.py +++ b/Lib/urllib/robotparser.py @@ -172,7 +172,7 @@ class RuleLine: return self.path == "*" or filename.startswith(self.path) def __str__(self): - return (self.allowance and "Allow" or "Disallow") + ": " + self.path + return ("Allow" if self.allowance else "Disallow") + ": " + self.path class Entry: diff --git a/Lib/warnings.py b/Lib/warnings.py index a427e35..f37b8a7 100644 --- a/Lib/warnings.py +++ b/Lib/warnings.py @@ -162,7 +162,9 @@ def warn(message, category=None, stacklevel=1): # Check category argument if category is None: category = UserWarning - assert issubclass(category, Warning) + if not (isinstance(category, type) and issubclass(category, Warning)): + raise TypeError("category must be a Warning subclass, " + "not '{:s}'".format(type(category).__name__)) # Get context information try: caller = sys._getframe(stacklevel) diff --git a/Lib/wsgiref/headers.py b/Lib/wsgiref/headers.py index d939628..7931bc7 100644 --- a/Lib/wsgiref/headers.py +++ b/Lib/wsgiref/headers.py @@ -26,10 +26,10 @@ def _formatparam(param, value=None, quote=1): class Headers: - """Manage a collection of HTTP response headers""" - def __init__(self,headers): + def __init__(self, headers=None): + headers = headers if headers is not None else [] if type(headers) is not list: raise TypeError("Headers must be a list of name/value tuples") self._headers = headers diff --git a/Lib/xmlrpc/client.py b/Lib/xmlrpc/client.py index c2ae707..567554d 100644 --- a/Lib/xmlrpc/client.py +++ b/Lib/xmlrpc/client.py @@ -1449,6 +1449,12 @@ class ServerProxy: return self.__transport raise AttributeError("Attribute %r not found" % (attr,)) + def __enter__(self): + return self + + def __exit__(self, *args): + self.__close() + # compatibility Server = ServerProxy |
