lib64/python3.6/abc.py 0000644 00000021027 15053243416 0010340 0 ustar 00 # 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
lib64/python3.8/abc.py 0000644 00000010611 15053243423 0010335 0 ustar 00 # Copyright 2007 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.
"""Abstract Base Classes (ABCs) according to PEP 3119."""
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. abstractmethod() may be used to declare
abstract methods for properties and descriptors.
Usage:
class C(metaclass=ABCMeta):
@abstractmethod
def my_abstract_method(self, ...):
...
"""
funcobj.__isabstractmethod__ = True
return funcobj
class abstractclassmethod(classmethod):
"""A decorator indicating abstract classmethods.
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.
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.
Deprecated, use 'property' with 'abstractmethod' instead.
"""
__isabstractmethod__ = True
try:
from _abc import (get_cache_token, _abc_init, _abc_register,
_abc_instancecheck, _abc_subclasscheck, _get_dump,
_reset_registry, _reset_caches)
except ImportError:
from _py_abc import ABCMeta, get_cache_token
ABCMeta.__module__ = 'abc'
else:
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()).
"""
def __new__(mcls, name, bases, namespace, **kwargs):
cls = super().__new__(mcls, name, bases, namespace, **kwargs)
_abc_init(cls)
return cls
def register(cls, subclass):
"""Register a virtual subclass of an ABC.
Returns the subclass, to allow usage as a class decorator.
"""
return _abc_register(cls, subclass)
def __instancecheck__(cls, instance):
"""Override for isinstance(instance, cls)."""
return _abc_instancecheck(cls, instance)
def __subclasscheck__(cls, subclass):
"""Override for issubclass(subclass, cls)."""
return _abc_subclasscheck(cls, subclass)
def _dump_registry(cls, file=None):
"""Debug helper to print the ABC registry."""
print(f"Class: {cls.__module__}.{cls.__qualname__}", file=file)
print(f"Inv. counter: {get_cache_token()}", file=file)
(_abc_registry, _abc_cache, _abc_negative_cache,
_abc_negative_cache_version) = _get_dump(cls)
print(f"_abc_registry: {_abc_registry!r}", file=file)
print(f"_abc_cache: {_abc_cache!r}", file=file)
print(f"_abc_negative_cache: {_abc_negative_cache!r}", file=file)
print(f"_abc_negative_cache_version: {_abc_negative_cache_version!r}",
file=file)
def _abc_registry_clear(cls):
"""Clear the registry (for debugging or testing)."""
_reset_registry(cls)
def _abc_caches_clear(cls):
"""Clear the caches (for debugging or testing)."""
_reset_caches(cls)
class ABC(metaclass=ABCMeta):
"""Helper class that provides a standard way to create an ABC using
inheritance.
"""
__slots__ = ()
lib64/python2.7/abc.py 0000644 00000015751 15053243447 0010353 0 ustar 00 # Copyright 2007 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.
"""Abstract Base Classes (ABCs) according to PEP 3119."""
import types
from _weakrefset import WeakSet
# Instance of old-style class
class _C: pass
_InstanceType = type(_C())
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 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)
"""
__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.
_abc_invalidation_counter = 0
def __new__(mcls, name, bases, namespace):
cls = super(ABCMeta, mcls).__new__(mcls, name, bases, namespace)
# Compute set of abstract method names
abstracts = set(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."""
if not isinstance(subclass, (type, types.ClassType)):
raise TypeError("Can only register classes")
if issubclass(subclass, cls):
return # 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
def _dump_registry(cls, file=None):
"""Debug helper to print the ABC registry."""
print >> file, "Class: %s.%s" % (cls.__module__, cls.__name__)
print >> file, "Inv.counter: %s" % ABCMeta._abc_invalidation_counter
for name in sorted(cls.__dict__.keys()):
if name.startswith("_abc_"):
value = getattr(cls, name)
print >> file, "%s: %r" % (name, value)
def __instancecheck__(cls, instance):
"""Override for isinstance(instance, cls)."""
# Inline the cache checking when it's simple.
subclass = getattr(instance, '__class__', None)
if subclass is not None and subclass in cls._abc_cache:
return True
subtype = type(instance)
# Old-style instances
if subtype is _InstanceType:
subtype = subclass
if subtype is subclass or subclass is None:
if (cls._abc_negative_cache_version ==
ABCMeta._abc_invalidation_counter and
subtype in cls._abc_negative_cache):
return False
# Fall back to the subclass check.
return cls.__subclasscheck__(subtype)
return (cls.__subclasscheck__(subclass) or
cls.__subclasscheck__(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
