1class Delegator:
2
3    # The cache is only used to be able to change delegates!
4
5    def __init__(self, delegate=None):
6        self.delegate = delegate
7        self.__cache = {}
8
9    def __getattr__(self, name):
10        attr = getattr(self.delegate, name) # May raise AttributeError
11        setattr(self, name, attr)
12        self.__cache[name] = attr
13        return attr
14
15    def resetcache(self):
16        for key in self.__cache.keys():
17            try:
18                delattr(self, key)
19            except AttributeError:
20                pass
21        self.__cache.clear()
22
23    def cachereport(self):
24        keys = self.__cache.keys()
25        keys.sort()
26        print keys
27
28    def setdelegate(self, delegate):
29        self.resetcache()
30        self.delegate = delegate
31
32    def getdelegate(self):
33        return self.delegate
34