Property caching decorator/property subclass

cache.py

"""
Stolen from:
https://bytes.com/topic/python/answers/751180-how-memoize-cache-property-access
"""
class cached(property):
    'Convert a method into a cached attribute'
    def __init__(self, method):
        private = '_' + method.__name__
        def fget(s):
            try:
                return getattr(s, private)
            except AttributeError:
                value = method(s)
                setattr(s, private, value)
                return value
        def fdel(s):
            if private in s.__dict__:
                del s.__dict__[private]

        super(cached, self).__init__(fget, fdel=fdel)

    @staticmethod
    def reset(self):
        cls = self.__class__
        for name in dir(cls):
            attr = getattr(cls, name)
            if isinstance(attr, cached):
                delattr(self, name)

if __name__ == '__main__': # a simple test
    import itertools
    counter = itertools.count()
    class Test(object):
        @cached
        def foo(self):
            return counter.next()

        @cached
        def bomb_moscow(self):
            print 'fire missiles'
            return counter.next() + 5

        reset = cached.reset

    a = Test()
    print a.foo
    print a.bomb_moscow

    print a.bomb_moscow

    print a.bomb_moscow