usr/lib64/python3.6/abc.py000064400000021027147204476340011161 0ustar00# Copyright 2007 Google, Inc. All Rights Reserved. # Licensed to PSF under a Contributor Agreement. """Abstract Base Classes (ABCs) according to PEP 3119.""" from _weakrefset import WeakSet def abstractmethod(funcobj): """A decorator indicating abstract methods. Requires that the metaclass is ABCMeta or derived from it. A class that has a metaclass derived from ABCMeta cannot be instantiated unless all of its abstract methods are overridden. The abstract methods can be called using any of the normal 'super' call mechanisms. Usage: class C(metaclass=ABCMeta): @abstractmethod def my_abstract_method(self, ...): ... """ funcobj.__isabstractmethod__ = True return funcobj class abstractclassmethod(classmethod): """ A decorator indicating abstract classmethods. Similar to abstractmethod. Usage: class C(metaclass=ABCMeta): @abstractclassmethod def my_abstract_classmethod(cls, ...): ... 'abstractclassmethod' is deprecated. Use 'classmethod' with 'abstractmethod' instead. """ __isabstractmethod__ = True def __init__(self, callable): callable.__isabstractmethod__ = True super().__init__(callable) class abstractstaticmethod(staticmethod): """ A decorator indicating abstract staticmethods. Similar to abstractmethod. Usage: class C(metaclass=ABCMeta): @abstractstaticmethod def my_abstract_staticmethod(...): ... 'abstractstaticmethod' is deprecated. Use 'staticmethod' with 'abstractmethod' instead. """ __isabstractmethod__ = True def __init__(self, callable): callable.__isabstractmethod__ = True super().__init__(callable) class abstractproperty(property): """ A decorator indicating abstract properties. Requires that the metaclass is ABCMeta or derived from it. A class that has a metaclass derived from ABCMeta cannot be instantiated unless all of its abstract properties are overridden. The abstract properties can be called using any of the normal 'super' call mechanisms. Usage: class C(metaclass=ABCMeta): @abstractproperty def my_abstract_property(self): ... This defines a read-only property; you can also define a read-write abstract property using the 'long' form of property declaration: class C(metaclass=ABCMeta): def getx(self): ... def setx(self, value): ... x = abstractproperty(getx, setx) 'abstractproperty' is deprecated. Use 'property' with 'abstractmethod' instead. """ __isabstractmethod__ = True class ABCMeta(type): """Metaclass for defining Abstract Base Classes (ABCs). Use this metaclass to create an ABC. An ABC can be subclassed directly, and then acts as a mix-in class. You can also register unrelated concrete classes (even built-in classes) and unrelated ABCs as 'virtual subclasses' -- these and their descendants will be considered subclasses of the registering ABC by the built-in issubclass() function, but the registering ABC won't show up in their MRO (Method Resolution Order) nor will method implementations defined by the registering ABC be callable (not even via super()). """ # A global counter that is incremented each time a class is # registered as a virtual subclass of anything. It forces the # negative cache to be cleared before its next use. # Note: this counter is private. Use `abc.get_cache_token()` for # external code. _abc_invalidation_counter = 0 def __new__(mcls, name, bases, namespace, **kwargs): cls = super().__new__(mcls, name, bases, namespace, **kwargs) # Compute set of abstract method names abstracts = {name for name, value in namespace.items() if getattr(value, "__isabstractmethod__", False)} for base in bases: for name in getattr(base, "__abstractmethods__", set()): value = getattr(cls, name, None) if getattr(value, "__isabstractmethod__", False): abstracts.add(name) cls.__abstractmethods__ = frozenset(abstracts) # Set up inheritance registry cls._abc_registry = WeakSet() cls._abc_cache = WeakSet() cls._abc_negative_cache = WeakSet() cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter return cls def register(cls, subclass): """Register a virtual subclass of an ABC. Returns the subclass, to allow usage as a class decorator. """ if not isinstance(subclass, type): raise TypeError("Can only register classes") if issubclass(subclass, cls): return subclass # Already a subclass # Subtle: test for cycles *after* testing for "already a subclass"; # this means we allow X.register(X) and interpret it as a no-op. if issubclass(cls, subclass): # This would create a cycle, which is bad for the algorithm below raise RuntimeError("Refusing to create an inheritance cycle") cls._abc_registry.add(subclass) ABCMeta._abc_invalidation_counter += 1 # Invalidate negative cache return subclass def _dump_registry(cls, file=None): """Debug helper to print the ABC registry.""" print("Class: %s.%s" % (cls.__module__, cls.__qualname__), file=file) print("Inv.counter: %s" % ABCMeta._abc_invalidation_counter, file=file) for name in sorted(cls.__dict__): if name.startswith("_abc_"): value = getattr(cls, name) if isinstance(value, WeakSet): value = set(value) print("%s: %r" % (name, value), file=file) def __instancecheck__(cls, instance): """Override for isinstance(instance, cls).""" # Inline the cache checking subclass = instance.__class__ if subclass in cls._abc_cache: return True subtype = type(instance) if subtype is subclass: if (cls._abc_negative_cache_version == ABCMeta._abc_invalidation_counter and subclass in cls._abc_negative_cache): return False # Fall back to the subclass check. return cls.__subclasscheck__(subclass) return any(cls.__subclasscheck__(c) for c in {subclass, subtype}) def __subclasscheck__(cls, subclass): """Override for issubclass(subclass, cls).""" # Check cache if subclass in cls._abc_cache: return True # Check negative cache; may have to invalidate if cls._abc_negative_cache_version < ABCMeta._abc_invalidation_counter: # Invalidate the negative cache cls._abc_negative_cache = WeakSet() cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter elif subclass in cls._abc_negative_cache: return False # Check the subclass hook ok = cls.__subclasshook__(subclass) if ok is not NotImplemented: assert isinstance(ok, bool) if ok: cls._abc_cache.add(subclass) else: cls._abc_negative_cache.add(subclass) return ok # Check if it's a direct subclass if cls in getattr(subclass, '__mro__', ()): cls._abc_cache.add(subclass) return True # Check if it's a subclass of a registered class (recursive) for rcls in cls._abc_registry: if issubclass(subclass, rcls): cls._abc_cache.add(subclass) return True # Check if it's a subclass of a subclass (recursive) for scls in cls.__subclasses__(): if issubclass(subclass, scls): cls._abc_cache.add(subclass) return True # No dice; update negative cache cls._abc_negative_cache.add(subclass) return False class ABC(metaclass=ABCMeta): """Helper class that provides a standard way to create an ABC using inheritance. """ pass def get_cache_token(): """Returns the current ABC cache token. The token is an opaque object (supporting equality testing) identifying the current version of the ABC cache for virtual subclasses. The token changes with every call to ``register()`` on any ABC. """ return ABCMeta._abc_invalidation_counter usr/lib64/python3.6/importlib/abc.py000064400000025036147204641500013156 0ustar00"""Abstract base classes related to import.""" from . import _bootstrap from . import _bootstrap_external from . import machinery try: import _frozen_importlib except ImportError as exc: if exc.name != '_frozen_importlib': raise _frozen_importlib = None try: import _frozen_importlib_external except ImportError as exc: _frozen_importlib_external = _bootstrap_external import abc def _register(abstract_cls, *classes): for cls in classes: abstract_cls.register(cls) if _frozen_importlib is not None: try: frozen_cls = getattr(_frozen_importlib, cls.__name__) except AttributeError: frozen_cls = getattr(_frozen_importlib_external, cls.__name__) abstract_cls.register(frozen_cls) class Finder(metaclass=abc.ABCMeta): """Legacy abstract base class for import finders. It may be subclassed for compatibility with legacy third party reimplementations of the import system. Otherwise, finder implementations should derive from the more specific MetaPathFinder or PathEntryFinder ABCs. """ @abc.abstractmethod def find_module(self, fullname, path=None): """An abstract method that should find a module. The fullname is a str and the optional path is a str or None. Returns a Loader object or None. """ class MetaPathFinder(Finder): """Abstract base class for import finders on sys.meta_path.""" # We don't define find_spec() here since that would break # hasattr checks we do to support backward compatibility. def find_module(self, fullname, path): """Return a loader for the module. If no module is found, return None. The fullname is a str and the path is a list of strings or None. This method is deprecated in favor of finder.find_spec(). If find_spec() exists then backwards-compatible functionality is provided for this method. """ if not hasattr(self, 'find_spec'): return None found = self.find_spec(fullname, path) return found.loader if found is not None else None def invalidate_caches(self): """An optional method for clearing the finder's cache, if any. This method is used by importlib.invalidate_caches(). """ _register(MetaPathFinder, machinery.BuiltinImporter, machinery.FrozenImporter, machinery.PathFinder, machinery.WindowsRegistryFinder) class PathEntryFinder(Finder): """Abstract base class for path entry finders used by PathFinder.""" # We don't define find_spec() here since that would break # hasattr checks we do to support backward compatibility. def find_loader(self, fullname): """Return (loader, namespace portion) for the path entry. The fullname is a str. The namespace portion is a sequence of path entries contributing to part of a namespace package. The sequence may be empty. If loader is not None, the portion will be ignored. The portion will be discarded if another path entry finder locates the module as a normal module or package. This method is deprecated in favor of finder.find_spec(). If find_spec() is provided than backwards-compatible functionality is provided. """ if not hasattr(self, 'find_spec'): return None, [] found = self.find_spec(fullname) if found is not None: if not found.submodule_search_locations: portions = [] else: portions = found.submodule_search_locations return found.loader, portions else: return None, [] find_module = _bootstrap_external._find_module_shim def invalidate_caches(self): """An optional method for clearing the finder's cache, if any. This method is used by PathFinder.invalidate_caches(). """ _register(PathEntryFinder, machinery.FileFinder) class Loader(metaclass=abc.ABCMeta): """Abstract base class for import loaders.""" def create_module(self, spec): """Return a module to initialize and into which to load. This method should raise ImportError if anything prevents it from creating a new module. It may return None to indicate that the spec should create the new module. """ # By default, defer to default semantics for the new module. return None # We don't define exec_module() here since that would break # hasattr checks we do to support backward compatibility. def load_module(self, fullname): """Return the loaded module. The module must be added to sys.modules and have import-related attributes set properly. The fullname is a str. ImportError is raised on failure. This method is deprecated in favor of loader.exec_module(). If exec_module() exists then it is used to provide a backwards-compatible functionality for this method. """ if not hasattr(self, 'exec_module'): raise ImportError return _bootstrap._load_module_shim(self, fullname) def module_repr(self, module): """Return a module's repr. Used by the module type when the method does not raise NotImplementedError. This method is deprecated. """ # The exception will cause ModuleType.__repr__ to ignore this method. raise NotImplementedError class ResourceLoader(Loader): """Abstract base class for loaders which can return data from their back-end storage. This ABC represents one of the optional protocols specified by PEP 302. """ @abc.abstractmethod def get_data(self, path): """Abstract method which when implemented should return the bytes for the specified path. The path must be a str.""" raise IOError class InspectLoader(Loader): """Abstract base class for loaders which support inspection about the modules they can load. This ABC represents one of the optional protocols specified by PEP 302. """ def is_package(self, fullname): """Optional method which when implemented should return whether the module is a package. The fullname is a str. Returns a bool. Raises ImportError if the module cannot be found. """ raise ImportError def get_code(self, fullname): """Method which returns the code object for the module. The fullname is a str. Returns a types.CodeType if possible, else returns None if a code object does not make sense (e.g. built-in module). Raises ImportError if the module cannot be found. """ source = self.get_source(fullname) if source is None: return None return self.source_to_code(source) @abc.abstractmethod def get_source(self, fullname): """Abstract method which should return the source code for the module. The fullname is a str. Returns a str. Raises ImportError if the module cannot be found. """ raise ImportError @staticmethod def source_to_code(data, path=''): """Compile 'data' into a code object. The 'data' argument can be anything that compile() can handle. The'path' argument should be where the data was retrieved (when applicable).""" return compile(data, path, 'exec', dont_inherit=True) exec_module = _bootstrap_external._LoaderBasics.exec_module load_module = _bootstrap_external._LoaderBasics.load_module _register(InspectLoader, machinery.BuiltinImporter, machinery.FrozenImporter) class ExecutionLoader(InspectLoader): """Abstract base class for loaders that wish to support the execution of modules as scripts. This ABC represents one of the optional protocols specified in PEP 302. """ @abc.abstractmethod def get_filename(self, fullname): """Abstract method which should return the value that __file__ is to be set to. Raises ImportError if the module cannot be found. """ raise ImportError def get_code(self, fullname): """Method to return the code object for fullname. Should return None if not applicable (e.g. built-in module). Raise ImportError if the module cannot be found. """ source = self.get_source(fullname) if source is None: return None try: path = self.get_filename(fullname) except ImportError: return self.source_to_code(source) else: return self.source_to_code(source, path) _register(ExecutionLoader, machinery.ExtensionFileLoader) class FileLoader(_bootstrap_external.FileLoader, ResourceLoader, ExecutionLoader): """Abstract base class partially implementing the ResourceLoader and ExecutionLoader ABCs.""" _register(FileLoader, machinery.SourceFileLoader, machinery.SourcelessFileLoader) class SourceLoader(_bootstrap_external.SourceLoader, ResourceLoader, ExecutionLoader): """Abstract base class for loading source code (and optionally any corresponding bytecode). To support loading from source code, the abstractmethods inherited from ResourceLoader and ExecutionLoader need to be implemented. To also support loading from bytecode, the optional methods specified directly by this ABC is required. Inherited abstractmethods not implemented in this ABC: * ResourceLoader.get_data * ExecutionLoader.get_filename """ def path_mtime(self, path): """Return the (int) modification time for the path (str).""" if self.path_stats.__func__ is SourceLoader.path_stats: raise IOError return int(self.path_stats(path)['mtime']) def path_stats(self, path): """Return a metadata dict for the source pointed to by the path (str). Possible keys: - 'mtime' (mandatory) is the numeric timestamp of last source code modification; - 'size' (optional) is the size in bytes of the source code. """ if self.path_mtime.__func__ is SourceLoader.path_mtime: raise IOError return {'mtime': self.path_mtime(path)} def set_data(self, path, data): """Write the bytes to the path (if possible). Accepts a str path and data as bytes. Any needed intermediary directories are to be created. If for some reason the file cannot be written because of permissions, fail silently. """ _register(SourceLoader, machinery.SourceFileLoader)