diff options
Diffstat (limited to 'Lib/pkgutil.py')
| -rw-r--r-- | Lib/pkgutil.py | 161 |
1 files changed, 75 insertions, 86 deletions
diff --git a/Lib/pkgutil.py b/Lib/pkgutil.py index 20e6498..a54e947 100644 --- a/Lib/pkgutil.py +++ b/Lib/pkgutil.py @@ -1,12 +1,14 @@ """Utilities to support packages.""" -import os -import sys +from functools import singledispatch as simplegeneric import importlib -import imp +import importlib.util +import importlib.machinery +import os import os.path -from warnings import warn +import sys from types import ModuleType +import warnings __all__ = [ 'get_importer', 'iter_importers', 'get_loader', 'find_loader', @@ -14,59 +16,34 @@ __all__ = [ 'ImpImporter', 'ImpLoader', 'read_code', 'extend_path', ] + +def _get_spec(finder, name): + """Return the finder-specific module spec.""" + # Works with legacy finders. + try: + find_spec = finder.find_spec + except AttributeError: + loader = finder.find_module(name) + if loader is None: + return None + return importlib.util.spec_from_loader(name, loader) + else: + return find_spec(name) + + def read_code(stream): # This helper is needed in order for the PEP 302 emulation to # correctly handle compiled files import marshal magic = stream.read(4) - if magic != imp.get_magic(): + if magic != importlib.util.MAGIC_NUMBER: return None stream.read(8) # Skip timestamp and size return marshal.load(stream) -def simplegeneric(func): - """Make a trivial single-dispatch generic function""" - registry = {} - def wrapper(*args, **kw): - ob = args[0] - try: - cls = ob.__class__ - except AttributeError: - cls = type(ob) - try: - mro = cls.__mro__ - except AttributeError: - try: - class cls(cls, object): - pass - mro = cls.__mro__[1:] - except TypeError: - mro = object, # must be an ExtensionClass or some such :( - for t in mro: - if t in registry: - return registry[t](*args, **kw) - else: - return func(*args, **kw) - try: - wrapper.__name__ = func.__name__ - except (TypeError, AttributeError): - pass # Python 2.3 doesn't allow functions to be renamed - - def register(typ, func=None): - if func is None: - return lambda f: register(typ, f) - registry[typ] = func - return func - - wrapper.__dict__ = func.__dict__ - wrapper.__doc__ = func.__doc__ - wrapper.register = register - return wrapper - - def walk_packages(path=None, prefix='', onerror=None): """Yields (module_loader, name, ispkg) for all modules recursively on path, or, if path is None, all accessible modules. @@ -121,8 +98,7 @@ def walk_packages(path=None, prefix='', onerror=None): # don't traverse path items we've seen before path = [p for p in path if not seen(p)] - for item in walk_packages(path, name+'.', onerror): - yield item + yield from walk_packages(path, name+'.', onerror) def iter_modules(path=None, prefix=''): @@ -149,13 +125,12 @@ def iter_modules(path=None, prefix=''): yield i, name, ispkg -#@simplegeneric +@simplegeneric def iter_importer_modules(importer, prefix=''): if not hasattr(importer, 'iter_modules'): return [] return importer.iter_modules(prefix) -iter_importer_modules = simplegeneric(iter_importer_modules) # Implement a file walker for the normal importlib path hook def _iter_file_finder_modules(importer, prefix=''): @@ -201,6 +176,13 @@ def _iter_file_finder_modules(importer, prefix=''): iter_importer_modules.register( importlib.machinery.FileFinder, _iter_file_finder_modules) + +def _import_imp(): + global imp + with warnings.catch_warnings(): + warnings.simplefilter('ignore', PendingDeprecationWarning) + imp = importlib.import_module('imp') + class ImpImporter: """PEP 302 Importer that wraps Python's "classic" import algorithm @@ -213,8 +195,10 @@ class ImpImporter: """ def __init__(self, path=None): - warn("This emulation is deprecated, use 'importlib' instead", + global imp + warnings.warn("This emulation is deprecated, use 'importlib' instead", DeprecationWarning) + _import_imp() self.path = path def find_module(self, fullname, path=None): @@ -279,8 +263,9 @@ class ImpLoader: code = source = None def __init__(self, fullname, file, filename, etc): - warn("This emulation is deprecated, use 'importlib' instead", - DeprecationWarning) + warnings.warn("This emulation is deprecated, use 'importlib' instead", + DeprecationWarning) + _import_imp() self.file = file self.filename = filename self.fullname = fullname @@ -350,16 +335,16 @@ class ImpLoader: self.file.close() elif mod_type==imp.PY_COMPILED: if os.path.exists(self.filename[:-1]): - f = open(self.filename[:-1], 'r') - self.source = f.read() - f.close() + with open(self.filename[:-1], 'r') as f: + self.source = f.read() elif mod_type==imp.PKG_DIRECTORY: self.source = self._get_delegate().get_source() return self.source - def _get_delegate(self): - return ImpImporter(self.filename).find_module('__init__') + finder = ImpImporter(self.filename) + spec = _get_spec(finder, '__init__') + return spec.loader def get_filename(self, fullname=None): fullname = self._fix_name(fullname) @@ -456,12 +441,12 @@ def iter_importers(fullname=""): if path is None: return else: - for importer in sys.meta_path: - yield importer + yield from sys.meta_path path = sys.path for item in path: yield get_importer(item) + def get_loader(module_or_name): """Get a PEP 302 "loader" object for module_or_name @@ -471,11 +456,15 @@ def get_loader(module_or_name): """ if module_or_name in sys.modules: module_or_name = sys.modules[module_or_name] + if module_or_name is None: + return None if isinstance(module_or_name, ModuleType): module = module_or_name loader = getattr(module, '__loader__', None) if loader is not None: return loader + if getattr(module, '__spec__', None) is None: + return None fullname = module.__name__ else: fullname = module_or_name @@ -485,29 +474,22 @@ def get_loader(module_or_name): def find_loader(fullname): """Find a PEP 302 "loader" object for fullname - This is s convenience wrapper around :func:`importlib.find_loader` that - sets the *path* argument correctly when searching for submodules, and - also ensures parent packages (if any) are imported before searching for - submodules. + This is a backwards compatibility wrapper around + importlib.util.find_spec that converts most failures to ImportError + and only returns the loader rather than the full spec """ if fullname.startswith('.'): msg = "Relative module name {!r} not supported".format(fullname) raise ImportError(msg) - path = None - pkg_name = fullname.rpartition(".")[0] - if pkg_name: - pkg = importlib.import_module(pkg_name) - path = getattr(pkg, "__path__", None) - if path is None: - return None try: - return importlib.find_loader(fullname, path) + spec = importlib.util.find_spec(fullname) except (ImportError, AttributeError, TypeError, ValueError) as ex: # This hack fixes an impedance mismatch between pkgutil and # importlib, where the latter raises other errors for cases where # pkgutil previously raised ImportError msg = "Error while finding loader for {!r} ({}: {})" raise ImportError(msg.format(fullname, type(ex), ex)) from ex + return spec.loader if spec is not None else None def extend_path(path, name): @@ -569,13 +551,14 @@ def extend_path(path, name): finder = get_importer(dir) if finder is not None: + portions = [] + if hasattr(finder, 'find_spec'): + spec = finder.find_spec(final_name) + if spec is not None: + portions = spec.submodule_search_locations or [] # Is this finder PEP 420 compliant? - if hasattr(finder, 'find_loader'): - loader, portions = finder.find_loader(final_name) - else: - # No, no need to call it - loader = None - portions = [] + elif hasattr(finder, 'find_loader'): + _, portions = finder.find_loader(final_name) for portion in portions: # XXX This may still add duplicate entries to path on @@ -589,19 +572,20 @@ def extend_path(path, name): if os.path.isfile(pkgfile): try: f = open(pkgfile) - except IOError as msg: + except OSError as msg: sys.stderr.write("Can't open %s: %s\n" % (pkgfile, msg)) else: - for line in f: - line = line.rstrip('\n') - if not line or line.startswith('#'): - continue - path.append(line) # Don't check for existence! - f.close() + with f: + for line in f: + line = line.rstrip('\n') + if not line or line.startswith('#'): + continue + path.append(line) # Don't check for existence! return path + def get_data(package, resource): """Get a resource from a package. @@ -624,10 +608,15 @@ def get_data(package, resource): which does not support get_data(), then None is returned. """ - loader = get_loader(package) + spec = importlib.util.find_spec(package) + if spec is None: + return None + loader = spec.loader if loader is None or not hasattr(loader, 'get_data'): return None - mod = sys.modules.get(package) or loader.load_module(package) + # XXX needs test + mod = (sys.modules.get(package) or + importlib._bootstrap._SpecMethods(spec).load()) if mod is None or not hasattr(mod, '__file__'): return None |