34 lines
1.1 KiB
Python
34 lines
1.1 KiB
Python
|
class Delegator:
|
||
|
|
|
||
|
|
def __init__(self, delegate=None):
|
||
|
|
self.delegate = delegate
|
||
|
|
self.__cache = set()
|
||
|
|
# Cache is used to only remove added attributes
|
||
|
|
# when changing the delegate.
|
||
|
|
|
||
|
|
def __getattr__(self, name):
|
||
|
|
attr = getattr(self.delegate, name) # May raise AttributeError
|
||
|
|
setattr(self, name, attr)
|
||
|
|
self.__cache.add(name)
|
||
|
|
return attr
|
||
|
|
|
||
|
|
def resetcache(self):
|
||
|
|
"Removes added attributes while leaving original attributes."
|
||
|
|
# Function is really about resetting delagator dict
|
||
|
|
# to original state. Cache is just a means
|
||
|
|
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)
|