diff options
Diffstat (limited to 'Lib/imp.py')
| -rw-r--r-- | Lib/imp.py | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/Lib/imp.py b/Lib/imp.py new file mode 100644 index 0000000000..419f631153 --- /dev/null +++ b/Lib/imp.py @@ -0,0 +1,255 @@ +"""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, + load_dynamic, get_frozen_object, is_frozen_package, + init_builtin, init_frozen, is_builtin, is_frozen, + _fix_co_filename, extension_suffixes) + +# Directly exposed by this module +from importlib._bootstrap import new_module +from importlib._bootstrap import cache_from_source, source_from_cache + + +from importlib import _bootstrap +from importlib import machinery +import os +import sys +import tokenize +import warnings + + +# DEPRECATED +SEARCH_ERROR = 0 +PY_SOURCE = 1 +PY_COMPILED = 2 +C_EXTENSION = 3 +PY_RESOURCE = 4 +PKG_DIRECTORY = 5 +C_BUILTIN = 6 +PY_FROZEN = 7 +PY_CODERESOURCE = 8 +IMP_HOOK = 9 + + +def get_magic(): + """Return the magic number for .pyc or .pyo files.""" + return _bootstrap._MAGIC_BYTES + + +def get_tag(): + """Return the magic tag for .pyc or .pyo files.""" + return sys.implementation.cache_tag + + +def get_suffixes(): + warnings.warn('imp.get_suffixes() is deprecated; use the constants ' + 'defined on importlib.machinery instead', + DeprecationWarning, 2) + extensions = [(s, 'rb', C_EXTENSION) for s in extension_suffixes()] + source = [(s, 'U', PY_SOURCE) for s in machinery.SOURCE_SUFFIXES] + bytecode = [(s, 'rb', PY_COMPILED) for s in machinery.BYTECODE_SUFFIXES] + + return extensions + source + bytecode + + +class NullImporter: + + """Null import object.""" + + def __init__(self, path): + if path == '': + raise ImportError('empty pathname', path='') + elif os.path.isdir(path): + raise ImportError('existing directory', path=path) + + def find_module(self, fullname): + """Always returns None.""" + return None + + +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): + msg = ('imp.load_source() is deprecated; use ' + 'importlib.machinery.SourceFileLoader(name, pathname).load_module()' + ' instead') + warnings.warn(msg, DeprecationWarning, 2) + 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): + msg = ('imp.load_compiled() is deprecated; use ' + 'importlib.machinery.SourcelessFileLoader(name, pathname).' + 'load_module() instead ') + warnings.warn(msg, DeprecationWarning, 2) + return _LoadCompiledCompatibility(name, pathname, file).load_module(name) + + +def load_package(name, path): + msg = ('imp.load_package() is deprecated; use either ' + 'importlib.machinery.SourceFileLoader() or ' + 'importlib.machinery.SourcelessFileLoader() instead') + warnings.warn(msg, DeprecationWarning, 2) + if os.path.isdir(path): + extensions = (machinery.SOURCE_SUFFIXES[:] + + machinery.BYTECODE_SUFFIXES[:]) + 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): + """**DEPRECATED** + + Load a module, given information returned by find_module(). + + The module name must include the full package name, if any. + + """ + suffix, mode, type_ = details + with warnings.catch_warnings(): + warnings.simplefilter('ignore') + 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) + + +def find_module(name, path=None): + """**DEPRECATED** + + Search for a module. + + If path is omitted or None, search for a built-in, frozen or special + module and continue search in sys.path. The module name cannot + contain '.'; to search for a submodule of a package, pass the + submodule name and the package's __path__. + + """ + if not isinstance(name, str): + raise TypeError("'name' must be a str, not {}".format(type(name))) + elif not isinstance(path, (type(None), list)): + # Backwards-compatibility + raise RuntimeError("'list' must be None or a list, " + "not {}".format(type(name))) + + if path is None: + if is_builtin(name): + return None, None, ('', '', C_BUILTIN) + elif is_frozen(name): + return None, None, ('', '', PY_FROZEN) + else: + path = sys.path + + for entry in path: + package_directory = os.path.join(entry, name) + for suffix in ['.py', machinery.BYTECODE_SUFFIXES[0]]: + package_file_name = '__init__' + suffix + file_path = os.path.join(package_directory, package_file_name) + if os.path.isfile(file_path): + return None, package_directory, ('', '', PKG_DIRECTORY) + with warnings.catch_warnings(): + warnings.simplefilter('ignore') + for suffix, mode, type_ in get_suffixes(): + file_name = name + suffix + file_path = os.path.join(entry, file_name) + if os.path.isfile(file_path): + break + else: + continue + break # Break out of outer loop when breaking out of inner loop. + else: + raise ImportError(_bootstrap._ERR_MSG.format(name), name=name) + + encoding = None + if mode == 'U': + with open(file_path, 'rb') as file: + encoding = tokenize.detect_encoding(file.readline)[0] + file = open(file_path, mode, encoding=encoding) + return file, file_path, (suffix, mode, type_) + + +_RELOADING = {} + +def reload(module): + """Reload the module and return it. + + The module must have been successfully imported before. + + """ + if not module or type(module) != type(sys): + raise TypeError("reload() argument must be module") + name = module.__name__ + if name not in sys.modules: + msg = "module {} not in sys.modules" + raise ImportError(msg.format(name), name=name) + if name in _RELOADING: + return _RELOADING[name] + _RELOADING[name] = module + try: + parent_name = name.rpartition('.')[0] + if parent_name and parent_name not in sys.modules: + msg = "parent {!r} not in sys.modules" + raise ImportError(msg.format(parentname), name=parent_name) + return module.__loader__.load_module(name) + finally: + try: + del _RELOADING[name] + except KeyError: + pass |