cpython/Lib/imp.py

110 lines
4.0 KiB
Python

"""This module provides the components needed to build your own __import__
function. Undocumented functions are obsolete.
In most cases it is preferred you consider using the importlib module's
functionality over this module.
"""
# (Probably) need to stay in _imp
from _imp import (lock_held, acquire_lock, release_lock, reload,
load_dynamic, get_frozen_object, is_frozen_package,
init_builtin, init_frozen, is_builtin, is_frozen,
_fix_co_filename)
# Could move out of _imp, but not worth the code
from _imp import get_magic
# Can (probably) move to importlib
from _imp import (get_tag, get_suffixes, source_from_cache)
# Should be re-implemented here (and mostly deprecated)
from _imp import (find_module, NullImporter,
SEARCH_ERROR, PY_SOURCE, PY_COMPILED, C_EXTENSION,
PY_RESOURCE, PKG_DIRECTORY, C_BUILTIN, PY_FROZEN,
PY_CODERESOURCE, IMP_HOOK)
from importlib._bootstrap import _new_module as new_module
from importlib._bootstrap import _cache_from_source as cache_from_source
from importlib import _bootstrap
import os
class _HackedGetData:
"""Compatibiilty support for 'file' arguments of various load_*()
functions."""
def __init__(self, fullname, path, file=None):
super().__init__(fullname, path)
self.file = file
def get_data(self, path):
"""Gross hack to contort loader to deal w/ load_*()'s bad API."""
if self.file and path == self._path:
with self.file:
# Technically should be returning bytes, but
# SourceLoader.get_code() just passed what is returned to
# compile() which can handle str. And converting to bytes would
# require figuring out the encoding to decode to and
# tokenize.detect_encoding() only accepts bytes.
return self.file.read()
else:
return super().get_data(path)
class _LoadSourceCompatibility(_HackedGetData, _bootstrap._SourceFileLoader):
"""Compatibility support for implementing load_source()."""
def load_source(name, pathname, file=None):
return _LoadSourceCompatibility(name, pathname, file).load_module(name)
class _LoadCompiledCompatibility(_HackedGetData,
_bootstrap._SourcelessFileLoader):
"""Compatibility support for implementing load_compiled()."""
def load_compiled(name, pathname, file=None):
return _LoadCompiledCompatibility(name, pathname, file).load_module(name)
def load_package(name, path):
if os.path.isdir(path):
extensions = _bootstrap._suffix_list(PY_SOURCE)
extensions += _bootstrap._suffix_list(PY_COMPILED)
for extension in extensions:
path = os.path.join(path, '__init__'+extension)
if os.path.exists(path):
break
else:
raise ValueError('{!r} is not a package'.format(path))
return _bootstrap._SourceFileLoader(name, path).load_module(name)
def load_module(name, file, filename, details):
"""Load a module, given information returned by find_module().
The module name must include the full package name, if any.
"""
suffix, mode, type_ = details
if mode and (not mode.startswith(('r', 'U')) or '+' in mode):
raise ValueError('invalid file open mode {!r}'.format(mode))
elif file is None and type_ in {PY_SOURCE, PY_COMPILED}:
msg = 'file object required for import (type code {})'.format(type_)
raise ValueError(msg)
elif type_ == PY_SOURCE:
return load_source(name, filename, file)
elif type_ == PY_COMPILED:
return load_compiled(name, filename, file)
elif type_ == PKG_DIRECTORY:
return load_package(name, filename)
elif type_ == C_BUILTIN:
return init_builtin(name)
elif type_ == PY_FROZEN:
return init_frozen(name)
else:
msg = "Don't know how to import {} (type code {}".format(name, type_)
raise ImportError(msg, name=name)