""" Define names for built-in types that aren't directly accessible as a builtin. """ import sys # Iterators in Python aren't a matter of type but of protocol. A large # and changing number of builtin types implement *some* flavor of # iterator. Don't check the type! Use hasattr to check for both # "__iter__" and "__next__" attributes instead. def _f(): pass FunctionType = type(_f) LambdaType = type(lambda: None) # Same as FunctionType CodeType = type(_f.__code__) MappingProxyType = type(type.__dict__) SimpleNamespace = type(sys.implementation) def _g(): yield 1 GeneratorType = type(_g()) class _C: def _m(self): pass MethodType = type(_C()._m) BuiltinFunctionType = type(len) BuiltinMethodType = type([].append) # Same as BuiltinFunctionType ModuleType = type(sys) try: raise TypeError except TypeError: tb = sys.exc_info()[2] TracebackType = type(tb) FrameType = type(tb.tb_frame) tb = None; del tb # For Jython, the following two types are identical GetSetDescriptorType = type(FunctionType.__code__) MemberDescriptorType = type(FunctionType.__globals__) del sys, _f, _g, _C, # Not for export # Provide a PEP 3115 compliant mechanism for class creation def new_class(name, bases=(), kwds=None, exec_body=None): """Create a class object dynamically using the appropriate metaclass.""" meta, ns, kwds = prepare_class(name, bases, kwds) if exec_body is not None: exec_body(ns) return meta(name, bases, ns, **kwds) def prepare_class(name, bases=(), kwds=None): """Call the __prepare__ method of the appropriate metaclass. Returns (metaclass, namespace, kwds) as a 3-tuple *metaclass* is the appropriate metaclass *namespace* is the prepared class namespace *kwds* is an updated copy of the passed in kwds argument with any 'metaclass' entry removed. If no kwds argument is passed in, this will be an empty dict. """ if kwds is None: kwds = {} else: kwds = dict(kwds) # Don't alter the provided mapping if 'metaclass' in kwds: meta = kwds.pop('metaclass') else: if bases: meta = type(bases[0]) else: meta = type if isinstance(meta, type): # when meta is a type, we first determine the most-derived metaclass # instead of invoking the initial candidate directly meta = _calculate_meta(meta, bases) if hasattr(meta, '__prepare__'): ns = meta.__prepare__(name, bases, **kwds) else: ns = {} return meta, ns, kwds def _calculate_meta(meta, bases): """Calculate the most derived metaclass.""" winner = meta for base in bases: base_meta = type(base) if issubclass(winner, base_meta): continue if issubclass(base_meta, winner): winner = base_meta continue # else: raise TypeError("metaclass conflict: " "the metaclass of a derived class " "must be a (non-strict) subclass " "of the metaclasses of all its bases") return winner class DynamicClassAttribute: """Route attribute access on a class to __getattr__. This is a descriptor, used to define attributes that act differently when accessed through an instance and through a class. Instance access remains normal, but access to an attribute through a class will be routed to the class's __getattr__ method; this is done by raising AttributeError. This allows one to have properties active on an instance, and have virtual attributes on the class with the same name (see Enum for an example). """ def __init__(self, fget=None, fset=None, fdel=None, doc=None): self.fget = fget self.fset = fset self.fdel = fdel # next two lines make DynamicClassAttribute act the same as property self.__doc__ = doc or fget.__doc__ self.overwrite_doc = doc is None # support for abstract methods self.__isabstractmethod__ = bool(getattr(fget, '__isabstractmethod__', False)) def __get__(self, instance, ownerclass=None): if instance is None: if self.__isabstractmethod__: return self raise AttributeError() elif self.fget is None: raise AttributeError("unreadable attribute") return self.fget(instance) def __set__(self, instance, value): if self.fset is None: raise AttributeError("can't set attribute") self.fset(instance, value) def __delete__(self, instance): if self.fdel is None: raise AttributeError("can't delete attribute") self.fdel(instance) def getter(self, fget): fdoc = fget.__doc__ if self.overwrite_doc else None result = type(self)(fget, self.fset, self.fdel, fdoc or self.__doc__) result.overwrite_doc = self.overwrite_doc return result def setter(self, fset): result = type(self)(self.fget, fset, self.fdel, self.__doc__) result.overwrite_doc = self.overwrite_doc return result def deleter(self, fdel): result = type(self)(self.fget, self.fset, fdel, self.__doc__) result.overwrite_doc = self.overwrite_doc return result import functools as _functools import collections.abc as _collections_abc def coroutine(func): """Convert regular generator function to a coroutine.""" # We don't want to import 'dis' or 'inspect' just for # these constants. CO_GENERATOR = 0x20 CO_ITERABLE_COROUTINE = 0x100 if not callable(func): raise TypeError('types.coroutine() expects a callable') if (isinstance(func, FunctionType) and isinstance(getattr(func, '__code__', None), CodeType) and (func.__code__.co_flags & CO_GENERATOR)): # TODO: Implement this in C. co = func.__code__ func.__code__ = CodeType( co.co_argcount, co.co_kwonlyargcount, co.co_nlocals, co.co_stacksize, co.co_flags | CO_ITERABLE_COROUTINE, co.co_code, co.co_consts, co.co_names, co.co_varnames, co.co_filename, co.co_name, co.co_firstlineno, co.co_lnotab, co.co_freevars, co.co_cellvars) return func # The following code is primarily to support functions that # return generator-like objects (for instance generators # compiled with Cython). class GeneratorWrapper: def __init__(self, gen): self.__wrapped__ = gen self.send = gen.send self.throw = gen.throw self.close = gen.close self.__name__ = getattr(gen, '__name__', None) self.__qualname__ = getattr(gen, '__qualname__', None) @property def gi_code(self): return self.__wrapped__.gi_code @property def gi_frame(self): return self.__wrapped__.gi_frame @property def gi_running(self): return self.__wrapped__.gi_running def __next__(self): return next(self.__wrapped__) def __iter__(self): return self.__wrapped__ __await__ = __iter__ @_functools.wraps(func) def wrapped(*args, **kwargs): coro = func(*args, **kwargs) if coro.__class__ is GeneratorType: return GeneratorWrapper(coro) # slow checks if not isinstance(coro, _collections_abc.Coroutine): if isinstance(coro, _collections_abc.Generator): return GeneratorWrapper(coro) raise TypeError( 'callable wrapped with types.coroutine() returned ' 'non-coroutine: {!r}'.format(coro)) return coro return wrapped __all__ = [n for n in globals() if n[:1] != '_']