diff options
-rw-r--r-- | six.py | 133 |
1 files changed, 98 insertions, 35 deletions
@@ -83,11 +83,7 @@ class _LazyDescr(object): self.name = name def __get__(self, obj, tp): - try: - result = self._resolve() - except ImportError: - # See the nice big comment in MovedModule.__getattr__. - raise AttributeError("%s could not be imported " % self.name) + result = self._resolve() setattr(obj, self.name, result) # Invokes __set__. # This is a bit ugly, but it avoids running this again. delattr(obj.__class__, self.name) @@ -109,22 +105,7 @@ class MovedModule(_LazyDescr): return _import_module(self.mod) def __getattr__(self, attr): - # It turns out many Python frameworks like to traverse sys.modules and - # try to load various attributes. This causes problems if this is a - # platform-specific module on the wrong platform, like _winreg on - # Unixes. Therefore, we silently pretend unimportable modules do not - # have any attributes. See issues #51, #53, #56, and #63 for the full - # tales of woe. - # - # First, if possible, avoid loading the module just to look at __file__, - # __name__, or __path__. - if (attr in ("__file__", "__name__", "__path__") and - self.mod not in sys.modules): - raise AttributeError(attr) - try: - _module = self._resolve() - except ImportError: - raise AttributeError(attr) + _module = self._resolve() value = getattr(_module, attr) setattr(self, attr, value) return value @@ -170,9 +151,72 @@ class MovedAttribute(_LazyDescr): return getattr(module, self.attr) +class _SixMetaPathImporter(object): + """ + A meta path importer to import six.moves and its submodules. + + This class implements a PEP302 finder and loader. It should be compatible + with Python 2.5 and all existing versions of Python3 + """ + def __init__(self, six_module_name): + self.name = six_module_name + self.known_modules = {} + + def _add_module(self, mod, *fullnames): + for fullname in fullnames: + self.known_modules[self.name + "." + fullname] = mod + + def _get_module(self, fullname): + return self.known_modules[self.name + "." + fullname] + + def find_module(self, fullname, path=None): + if fullname in self.known_modules: + return self + return None + + def __get_module(self, fullname): + try: + return self.known_modules[fullname] + except KeyError: + raise ImportError("This loader does not know module " + fullname) + + def load_module(self, fullname): + try: + # in case of a reload + return sys.modules[fullname] + except KeyError: + pass + mod = self.__get_module(fullname) + if isinstance(mod, MovedModule): + mod = mod._resolve() + else: + mod.__loader__ = self + sys.modules[fullname] = mod + return mod + + def is_package(self, fullname): + """ + Return true, if the named module is a package. + + We need this method to get correct spec objects with + Python 3.4 (see PEP451) + """ + return hasattr(self.__get_module(fullname), "__path__") + + def get_code(self, fullname): + """Return None + + Required, if is_package is implemented""" + self.__get_module(fullname) # eventually raises ImportError + return None + get_source = get_code # same as get_code + +_importer = _SixMetaPathImporter(__name__) + class _MovedItems(_LazyModule): """Lazy loading of moved objects""" + __path__ = [] # mark as package _moved_attributes = [ @@ -239,12 +283,13 @@ _moved_attributes = [ for attr in _moved_attributes: setattr(_MovedItems, attr.name, attr) if isinstance(attr, MovedModule): - sys.modules[__name__ + ".moves." + attr.name] = attr + _importer._add_module(attr, "moves." + attr.name) del attr _MovedItems._moved_attributes = _moved_attributes -moves = sys.modules[__name__ + ".moves"] = _MovedItems(__name__ + ".moves") +moves = _MovedItems(__name__ + ".moves") +_importer._add_module(moves, "moves") class Module_six_moves_urllib_parse(_LazyModule): @@ -275,7 +320,8 @@ del attr Module_six_moves_urllib_parse._moved_attributes = _urllib_parse_moved_attributes -sys.modules[__name__ + ".moves.urllib_parse"] = sys.modules[__name__ + ".moves.urllib.parse"] = Module_six_moves_urllib_parse(__name__ + ".moves.urllib_parse") +_importer._add_module(Module_six_moves_urllib_parse(__name__ + ".moves.urllib_parse"), + "moves.urllib_parse", "moves.urllib.parse") class Module_six_moves_urllib_error(_LazyModule): @@ -293,7 +339,8 @@ del attr Module_six_moves_urllib_error._moved_attributes = _urllib_error_moved_attributes -sys.modules[__name__ + ".moves.urllib_error"] = sys.modules[__name__ + ".moves.urllib.error"] = Module_six_moves_urllib_error(__name__ + ".moves.urllib.error") +_importer._add_module(Module_six_moves_urllib_error(__name__ + ".moves.urllib.error"), + "moves.urllib_error", "moves.urllib.error") class Module_six_moves_urllib_request(_LazyModule): @@ -341,7 +388,8 @@ del attr Module_six_moves_urllib_request._moved_attributes = _urllib_request_moved_attributes -sys.modules[__name__ + ".moves.urllib_request"] = sys.modules[__name__ + ".moves.urllib.request"] = Module_six_moves_urllib_request(__name__ + ".moves.urllib.request") +_importer._add_module(Module_six_moves_urllib_request(__name__ + ".moves.urllib.request"), + "moves.urllib_request", "moves.urllib.request") class Module_six_moves_urllib_response(_LazyModule): @@ -360,7 +408,8 @@ del attr Module_six_moves_urllib_response._moved_attributes = _urllib_response_moved_attributes -sys.modules[__name__ + ".moves.urllib_response"] = sys.modules[__name__ + ".moves.urllib.response"] = Module_six_moves_urllib_response(__name__ + ".moves.urllib.response") +_importer._add_module(Module_six_moves_urllib_response(__name__ + ".moves.urllib.response"), + "moves.urllib_response", "moves.urllib.response") class Module_six_moves_urllib_robotparser(_LazyModule): @@ -376,22 +425,24 @@ del attr Module_six_moves_urllib_robotparser._moved_attributes = _urllib_robotparser_moved_attributes -sys.modules[__name__ + ".moves.urllib_robotparser"] = sys.modules[__name__ + ".moves.urllib.robotparser"] = Module_six_moves_urllib_robotparser(__name__ + ".moves.urllib.robotparser") +_importer._add_module(Module_six_moves_urllib_robotparser(__name__ + ".moves.urllib.robotparser"), + "moves.urllib_robotparser", "moves.urllib.robotparser") class Module_six_moves_urllib(types.ModuleType): """Create a six.moves.urllib namespace that resembles the Python 3 namespace""" - parse = sys.modules[__name__ + ".moves.urllib_parse"] - error = sys.modules[__name__ + ".moves.urllib_error"] - request = sys.modules[__name__ + ".moves.urllib_request"] - response = sys.modules[__name__ + ".moves.urllib_response"] - robotparser = sys.modules[__name__ + ".moves.urllib_robotparser"] + __path__ = [] # mark as package + parse = _importer._get_module("moves.urllib_parse") + error = _importer._get_module("moves.urllib_error") + request = _importer._get_module("moves.urllib_request") + response = _importer._get_module("moves.urllib_response") + robotparser = _importer._get_module("moves.urllib_robotparser") def __dir__(self): return ['parse', 'error', 'request', 'response', 'robotparser'] - -sys.modules[__name__ + ".moves.urllib"] = Module_six_moves_urllib(__name__ + ".moves.urllib") +_importer._add_module(Module_six_moves_urllib(__name__ + ".moves.urllib"), + "moves.urllib") def add_move(move): @@ -644,3 +695,15 @@ def add_metaclass(metaclass): orig_vars.pop(slots_var) return metaclass(cls.__name__, cls.__bases__, orig_vars) return wrapper + +# Complete the moves implementation. +# This code is at the end of this module to speed up module loading. +# 1. turn this module into a package. +__path__ = [] # required for PEP 302 and PEP 451 +__package__ = __name__ # see PEP 366 @ReservedAssignment +try: + __spec__.submodule_search_locations = [] # PEP 451 @UndefinedVariable +except NameError: + pass +# 2. add the importer to the meta path import hook. +sys.meta_path.append(_importer) |