Immutable objects made mutable

mutable.py

#By Robin Wellner (gvx)
#I hereby waive copyright and related or neighboring rights to this work
#See the Creative Commons Zero Waiver at <http://creativecommons.org/publicdomain/zero/1.0/>

class mutable(object):
    def __init__(self, obj):
        self._obj = obj
    def __repr__(self):
        return 'mutable('+repr(self._obj)+')'
    def __call__(self, obj=None):
        oldobj = self._obj
        if obj is not None:
            self._obj = obj
        return oldobj
    def __getattr__(self, name):
        return self._obj.__getattribute__(name)