class Delegator:
def __init__(self, delegate=None):
self.delegate = delegate
self.__cache = set()
def __getattr__(self, name):
attr = getattr(self.delegate, name) setattr(self, name, attr)
self.__cache.add(name)
return attr
def resetcache(self):
"Removes added attributes while leaving original attributes."
for key in self.__cache:
try:
delattr(self, key)
except AttributeError:
pass
self.__cache.clear()
def setdelegate(self, delegate):
"Reset attributes and change delegate."
self.resetcache()
self.delegate = delegate
if __name__ == '__main__':
from unittest import main
main('idlelib.idle_test.test_delegator', verbosity=2)