diff options
| -rw-r--r-- | Doc/whatsnew/3.2.rst | 69 |
1 files changed, 50 insertions, 19 deletions
diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst index f96aa8b..4b4bbed 100644 --- a/Doc/whatsnew/3.2.rst +++ b/Doc/whatsnew/3.2.rst @@ -513,6 +513,7 @@ Some smaller changes made to the core Python language are: caused confusion and is no longer needed now that the shortest possible :func:`repr` is displayed by default: + >>> import math >>> repr(math.pi) '3.141592653589793' >>> str(math.pi) @@ -633,11 +634,10 @@ Some smaller changes made to the core Python language are: (See :issue:`10518`.) * Python's import mechanism can now load modules installed in directories with - non-ASCII characters in the path name: + non-ASCII characters in the path name. This solved an aggravating problem + with home directories for users with non-ASCII characters in their usernames. - >>> import møøse.bites - - (Required extensive work by Victor Stinner in :issue:`9425`.) + (Required extensive work by Victor Stinner in :issue:`9425`.) New, Improved, and Deprecated Modules @@ -646,14 +646,15 @@ New, Improved, and Deprecated Modules Python's standard library has undergone significant maintenance efforts and quality improvements. -The biggest news for Python 3.2 is that the :mod:`email` package and -:mod:`nntplib` modules now work correctly with the bytes/text model in Python 3. -For the first time, there is correct handling of inputs with mixed encodings. +The biggest news for Python 3.2 is that the :mod:`email` package, :mod:`mailbox` +module, and :mod:`nntplib` modules now work correctly with the bytes/text model +in Python 3. For the first time, there is correct handling of message with +mixed encodings. Throughout the standard library, there has been more careful attention to encodings and text versus bytes issues. In particular, interactions with the -operating system are now better able to pass non-ASCII data using the Windows -MBCS encoding, locale-aware encodings, or UTF-8. +operating system are now better able to exchange non-ASCII data using the +Windows MBCS encoding, locale-aware encodings, or UTF-8. Another significant win is the addition of substantially better support for *SSL* connections and security certificates. @@ -822,6 +823,7 @@ itertools * The :mod:`itertools` module has a new :func:`~itertools.accumulate` function modeled on APL's *scan* operator and Numpy's *accumulate* function: + >>> from itertools import accumulate >>> list(accumulate(8, 2, 50)) [8, 10, 60] @@ -911,6 +913,8 @@ back and re-enter the barrier. The barrier fully resets after each cycle. Example of using barriers:: + from threading import Barrier, Thread + def get_votes(site): ballots = conduct_election(site) all_polls_closed.wait() # do not count until all polls are closed @@ -964,7 +968,7 @@ datetime and time offset and timezone name. This makes it easier to create timezone-aware datetime objects:: - >>> import datetime + >>> from datetime import datetime, timezone >>> datetime.now(timezone.utc) datetime.datetime(2010, 12, 8, 21, 4, 2, 923754, tzinfo=datetime.timezone.utc) @@ -1069,12 +1073,12 @@ These tools make it possible to define an :term:`abstract base class` that requires a particular :func:`classmethod` or :func:`staticmethod` to be implemented:: - class Temperature(metaclass=ABCMeta): + class Temperature(metaclass=abc.ABCMeta): @abc.abstractclassmethod - def from_fahrenheit(self, t): + def from_fahrenheit(cls, t): ... @abc.abstractclassmethod - def from_celsius(self, t): + def from_celsius(cls, t): ... (Patch submitted by Daniel Urban; :issue:`5867`.) @@ -1104,8 +1108,8 @@ for slice notation are well-suited to in-place editing:: >>> change_location(buffer, 1, b'warehouse ') >>> change_location(buffer, 0, b'showroom ') >>> print(byte_stream.getvalue()) - b'G3805 showroom Main chassis ' -> - b'X7899 warehouse Reserve cog ' -> + b'G3805 showroom Main chassis ' + b'X7899 warehouse Reserve cog ' b'L6988 receiving Primary sprocket' (Contributed by Antoine Pitrou in :issue:`5506`.) @@ -1425,7 +1429,7 @@ strings, bytes, numbers, tuples, lists, dicts, sets, booleans, and None. :: - >>> from ast import literal_request + >>> from ast import literal_eval >>> request = "{'req': 3, 'func': 'pow', 'args': (2, 0.5)}" >>> literal_eval(request) @@ -1491,7 +1495,8 @@ step is non-destructive (the original files are left unchanged). >>> import shutil, pprint >>> os.chdir('mydata') # change to the source directory - >>> f = make_archive('/var/backup/mydata', 'zip') # archive the current directory + >>> f = shutil.make_archive('/var/backup/mydata', + 'zip') # archive the current directory >>> f # show the name of archive '/var/backup/mydata.zip' >>> os.chdir('tmp') # change to an unpacking @@ -1505,8 +1510,8 @@ step is non-destructive (the original files are left unchanged). >>> shutil.register_archive_format( # register a new archive format name = 'xz', - function = 'xz.compress', - extra_args = [('level', 8)], + function = xz.compress, # callable archiving function + extra_args = [('level', 8)], # arguments to the function description = 'xz compression' ) @@ -1879,6 +1884,32 @@ object. The former returns a string and the latter prints it:: 1: seq 2: i +In addition, the :func:`~dis.dis` function now accepts string arguments +so that the common idiom ``dis(compile(s, '', 'eval'))`` can be shortened +to ``dis(compile(s))``:: + + >>> dis('3*x+1 if x%2==1 else x//2') + 1 0 LOAD_NAME 0 (x) + 3 LOAD_CONST 0 (2) + 6 BINARY_MODULO + 7 LOAD_CONST 1 (1) + 10 COMPARE_OP 2 (==) + 13 POP_JUMP_IF_FALSE 28 + 16 LOAD_CONST 2 (3) + 19 LOAD_NAME 0 (x) + 22 BINARY_MULTIPLY + 23 LOAD_CONST 1 (1) + 26 BINARY_ADD + 27 RETURN_VALUE + >> 28 LOAD_NAME 0 (x) + 31 LOAD_CONST 0 (2) + 34 BINARY_FLOOR_DIVIDE + 35 RETURN_VALUE + +Taken together, these improvements make it easier to explore how CPython is +implemented and to see for yourself what the language syntax does +under-the-hood. + (Contributed by Nick Coghlan in :issue:`9147`.) dbm |