Viewing file:  properties.py (1.32 KB) -rw-r--r--
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from ..py32compat import abc
__metaclass__ = type
class ClassProperty(property):
"""
An implementation of a property callable on a class. Used to decorate a
classmethod but to then treat it like a property.
Example:
>>> class MyClass:
... @ClassProperty
... @classmethod
... def skillz(cls):
... return cls.__name__.startswith('My')
>>> MyClass.skillz
True
>>> class YourClass(MyClass): pass
>>> YourClass.skillz
False
"""
def __get__(self, cls, owner):
return self.fget.__get__(None, owner)()
# borrowed from jaraco.util.dictlib
class NonDataProperty:
"""Much like the property builtin, but only implements __get__,
making it a non-data property, and can be subsequently reset.
See http://users.rcn.com/python/download/Descriptor.htm for more
information.
>>> class X:
... @NonDataProperty
... def foo(self):
... return 3
>>> x = X()
>>> x.foo
3
>>> x.foo = 4
>>> x.foo
4
"""
def __init__(self, fget):
assert fget is not None, "fget cannot be none"
assert isinstance(fget, abc.Callable), "fget must be callable"
self.fget = fget
def __get__(self, obj, objtype=None):
if obj is None:
return self
return self.fget(obj)
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