Currently, if I want to have weakref.finalize call an object's cleanup method, I have to do something like:

class foo:

_finalizer = None

def __init__(self): self._finalizer = weakref.finalize(self, foo._cleanup,

weakref.WeakMethod(self.cleanup))

def __del__(self): self.cleanup()

@classmethod def _cleanup(cls, func): func()()

def cleanup(self): if self._finalizer is not None: self._finalizer.detach() print('cleaning up')

It wouldn't be difficult to have weakref.finalize automatically handle the conversion to WeakMethod and automatically attempt to dereference then call the function passed in.