def memoizedproperty(func):
    """
    Decorator to cause a method to cache it's results in self for each
    combination of inputs and return the cached result on subsequent calls.
    Does not support named arguments or arg values that are not hashable.

    >>> class Foo (object):
    ...   _x = 1
    ...   @memoizedproperty
    ...   def foo(self):
    ...     self._x += 1
    ...     print('updating and returning {0}'.format(self._x))
    ...     return self._x
    ...
    >>> foo1 = Foo()
    >>> foo2 = Foo()
    >>> foo1.foo
    updating and returning 2
    2
    >>> foo1.foo
    2
    >>> foo2.foo
    updating and returning 2
    2
    >>> foo1.foo
    2
    """
    inner_attname = '__%s' % func.__name__

    def new_fget(self):
        if not hasattr(self, '_cache_'):
            self._cache_ = dict()
        cache = self._cache_
        if inner_attname not in cache:
            cache[inner_attname] = func(self)
        return cache[inner_attname]

    return property(new_fget)