mirror of
https://github.com/python/cpython.git
synced 2024-11-27 11:55:13 +08:00
d5cacbb1d9
Known limitations of the current implementation: - documentation changes are incomplete - there's a reference leak I haven't tracked down yet The leak is most visible by running: ./python -m test -R3:3 test_importlib However, you can also see it by running: ./python -X showrefcount Importing the array or _testmultiphase modules, and then deleting them from both sys.modules and the local namespace shows significant increases in the total number of active references each cycle. By contrast, with _testcapi (which continues to use single-phase initialisation) the global refcounts stabilise after a couple of cycles.
340 lines
10 KiB
Python
340 lines
10 KiB
Python
"""This module provides the components needed to build your own __import__
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function. Undocumented functions are obsolete.
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In most cases it is preferred you consider using the importlib module's
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functionality over this module.
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"""
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# (Probably) need to stay in _imp
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from _imp import (lock_held, acquire_lock, release_lock,
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get_frozen_object, is_frozen_package,
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init_frozen, is_builtin, is_frozen,
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_fix_co_filename)
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try:
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from _imp import create_dynamic
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except ImportError:
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# Platform doesn't support dynamic loading.
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create_dynamic = None
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from importlib._bootstrap import _ERR_MSG, _exec, _load, _builtin_from_name
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from importlib._bootstrap_external import SourcelessFileLoader
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from importlib import machinery
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from importlib import util
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import importlib
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import os
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import sys
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import tokenize
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import types
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import warnings
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warnings.warn("the imp module is deprecated in favour of importlib; "
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"see the module's documentation for alternative uses",
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PendingDeprecationWarning, stacklevel=2)
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# DEPRECATED
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SEARCH_ERROR = 0
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PY_SOURCE = 1
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PY_COMPILED = 2
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C_EXTENSION = 3
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PY_RESOURCE = 4
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PKG_DIRECTORY = 5
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C_BUILTIN = 6
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PY_FROZEN = 7
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PY_CODERESOURCE = 8
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IMP_HOOK = 9
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def new_module(name):
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"""**DEPRECATED**
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Create a new module.
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The module is not entered into sys.modules.
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"""
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return types.ModuleType(name)
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def get_magic():
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"""**DEPRECATED**
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Return the magic number for .pyc files.
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"""
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return util.MAGIC_NUMBER
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def get_tag():
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"""Return the magic tag for .pyc files."""
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return sys.implementation.cache_tag
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def cache_from_source(path, debug_override=None):
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"""**DEPRECATED**
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Given the path to a .py file, return the path to its .pyc file.
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The .py file does not need to exist; this simply returns the path to the
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.pyc file calculated as if the .py file were imported.
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If debug_override is not None, then it must be a boolean and is used in
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place of sys.flags.optimize.
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If sys.implementation.cache_tag is None then NotImplementedError is raised.
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"""
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with warnings.catch_warnings():
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warnings.simplefilter('ignore')
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return util.cache_from_source(path, debug_override)
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def source_from_cache(path):
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"""**DEPRECATED**
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Given the path to a .pyc. file, return the path to its .py file.
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The .pyc file does not need to exist; this simply returns the path to
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the .py file calculated to correspond to the .pyc file. If path does
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not conform to PEP 3147 format, ValueError will be raised. If
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sys.implementation.cache_tag is None then NotImplementedError is raised.
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"""
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return util.source_from_cache(path)
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def get_suffixes():
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"""**DEPRECATED**"""
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extensions = [(s, 'rb', C_EXTENSION) for s in machinery.EXTENSION_SUFFIXES]
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source = [(s, 'r', PY_SOURCE) for s in machinery.SOURCE_SUFFIXES]
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bytecode = [(s, 'rb', PY_COMPILED) for s in machinery.BYTECODE_SUFFIXES]
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return extensions + source + bytecode
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class NullImporter:
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"""**DEPRECATED**
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Null import object.
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"""
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def __init__(self, path):
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if path == '':
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raise ImportError('empty pathname', path='')
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elif os.path.isdir(path):
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raise ImportError('existing directory', path=path)
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def find_module(self, fullname):
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"""Always returns None."""
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return None
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class _HackedGetData:
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"""Compatibility support for 'file' arguments of various load_*()
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functions."""
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def __init__(self, fullname, path, file=None):
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super().__init__(fullname, path)
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self.file = file
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def get_data(self, path):
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"""Gross hack to contort loader to deal w/ load_*()'s bad API."""
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if self.file and path == self.path:
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if not self.file.closed:
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file = self.file
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else:
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self.file = file = open(self.path, 'r')
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with file:
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# Technically should be returning bytes, but
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# SourceLoader.get_code() just passed what is returned to
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# compile() which can handle str. And converting to bytes would
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# require figuring out the encoding to decode to and
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# tokenize.detect_encoding() only accepts bytes.
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return file.read()
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else:
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return super().get_data(path)
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class _LoadSourceCompatibility(_HackedGetData, machinery.SourceFileLoader):
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"""Compatibility support for implementing load_source()."""
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def load_source(name, pathname, file=None):
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loader = _LoadSourceCompatibility(name, pathname, file)
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spec = util.spec_from_file_location(name, pathname, loader=loader)
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if name in sys.modules:
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module = _exec(spec, sys.modules[name])
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else:
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module = _load(spec)
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# To allow reloading to potentially work, use a non-hacked loader which
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# won't rely on a now-closed file object.
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module.__loader__ = machinery.SourceFileLoader(name, pathname)
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module.__spec__.loader = module.__loader__
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return module
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class _LoadCompiledCompatibility(_HackedGetData, SourcelessFileLoader):
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"""Compatibility support for implementing load_compiled()."""
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def load_compiled(name, pathname, file=None):
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"""**DEPRECATED**"""
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loader = _LoadCompiledCompatibility(name, pathname, file)
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spec = util.spec_from_file_location(name, pathname, loader=loader)
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if name in sys.modules:
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module = _exec(spec, sys.modules[name])
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else:
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module = _load(spec)
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# To allow reloading to potentially work, use a non-hacked loader which
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# won't rely on a now-closed file object.
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module.__loader__ = SourcelessFileLoader(name, pathname)
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module.__spec__.loader = module.__loader__
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return module
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def load_package(name, path):
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"""**DEPRECATED**"""
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if os.path.isdir(path):
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extensions = (machinery.SOURCE_SUFFIXES[:] +
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machinery.BYTECODE_SUFFIXES[:])
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for extension in extensions:
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path = os.path.join(path, '__init__'+extension)
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if os.path.exists(path):
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break
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else:
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raise ValueError('{!r} is not a package'.format(path))
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spec = util.spec_from_file_location(name, path,
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submodule_search_locations=[])
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if name in sys.modules:
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return _exec(spec, sys.modules[name])
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else:
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return _load(spec)
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def load_module(name, file, filename, details):
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"""**DEPRECATED**
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Load a module, given information returned by find_module().
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The module name must include the full package name, if any.
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"""
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suffix, mode, type_ = details
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if mode and (not mode.startswith(('r', 'U')) or '+' in mode):
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raise ValueError('invalid file open mode {!r}'.format(mode))
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elif file is None and type_ in {PY_SOURCE, PY_COMPILED}:
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msg = 'file object required for import (type code {})'.format(type_)
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raise ValueError(msg)
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elif type_ == PY_SOURCE:
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return load_source(name, filename, file)
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elif type_ == PY_COMPILED:
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return load_compiled(name, filename, file)
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elif type_ == C_EXTENSION and load_dynamic is not None:
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if file is None:
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with open(filename, 'rb') as opened_file:
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return load_dynamic(name, filename, opened_file)
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else:
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return load_dynamic(name, filename, file)
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elif type_ == PKG_DIRECTORY:
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return load_package(name, filename)
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elif type_ == C_BUILTIN:
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return init_builtin(name)
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elif type_ == PY_FROZEN:
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return init_frozen(name)
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else:
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msg = "Don't know how to import {} (type code {})".format(name, type_)
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raise ImportError(msg, name=name)
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def find_module(name, path=None):
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"""**DEPRECATED**
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Search for a module.
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If path is omitted or None, search for a built-in, frozen or special
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module and continue search in sys.path. The module name cannot
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contain '.'; to search for a submodule of a package, pass the
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submodule name and the package's __path__.
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"""
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if not isinstance(name, str):
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raise TypeError("'name' must be a str, not {}".format(type(name)))
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elif not isinstance(path, (type(None), list)):
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# Backwards-compatibility
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raise RuntimeError("'list' must be None or a list, "
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"not {}".format(type(name)))
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if path is None:
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if is_builtin(name):
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return None, None, ('', '', C_BUILTIN)
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elif is_frozen(name):
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return None, None, ('', '', PY_FROZEN)
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else:
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path = sys.path
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for entry in path:
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package_directory = os.path.join(entry, name)
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for suffix in ['.py', machinery.BYTECODE_SUFFIXES[0]]:
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package_file_name = '__init__' + suffix
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file_path = os.path.join(package_directory, package_file_name)
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if os.path.isfile(file_path):
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return None, package_directory, ('', '', PKG_DIRECTORY)
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for suffix, mode, type_ in get_suffixes():
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file_name = name + suffix
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file_path = os.path.join(entry, file_name)
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if os.path.isfile(file_path):
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break
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else:
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continue
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break # Break out of outer loop when breaking out of inner loop.
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else:
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raise ImportError(_ERR_MSG.format(name), name=name)
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encoding = None
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if 'b' not in mode:
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with open(file_path, 'rb') as file:
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encoding = tokenize.detect_encoding(file.readline)[0]
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file = open(file_path, mode, encoding=encoding)
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return file, file_path, (suffix, mode, type_)
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def reload(module):
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"""**DEPRECATED**
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Reload the module and return it.
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The module must have been successfully imported before.
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"""
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return importlib.reload(module)
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def init_builtin(name):
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"""**DEPRECATED**
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Load and return a built-in module by name, or None is such module doesn't
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exist
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"""
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try:
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return _builtin_from_name(name)
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except ImportError:
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return None
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if create_dynamic:
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def load_dynamic(name, path, file=None):
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"""**DEPRECATED**
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Load an extension module.
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"""
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import importlib.machinery
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loader = importlib.machinery.ExtensionFileLoader(name, path)
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return loader.load_module()
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else:
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load_dynamic = None
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