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copied!<p>sj26's solution is a good one. Another alternative, if you want to set up a method that can be overloaded with any user-supplied function or with another of the object's methods, is build a custom descriptor. This descriptor can be used as a decorator (analogous to @classmethod or @staticmethod); and it allows you to store a function in an instance's dictionary, and returns it as a method:</p> <pre><code>import types class overloadable(object): def __init__(self, func): self._default_func = func self._name = func.__name__ def __get__(self, obj, type=None): func = obj.__dict__.get(self._name, self._default_func) return types.MethodType(func, obj, type) def __set__(self, obj, value): if hasattr(value, 'im_func'): value = value.im_func obj.__dict__[self._name] = value def __delete__(self, obj): del obj.__dict__[self._name] </code></pre> <p>Now we can just decorate a function with "@overloadable":</p> <pre><code>class SomeClass(object): def doStuff(self, string): print 'do stuff:', string @overloadable def overLoaded(self, arg): print 'default behavior:', arg </code></pre> <p>And it'll just do the right thing when we overload it for a given instance:</p> <pre><code>>>> sc = SomeClass() >>> sc.overLoaded("test string") # Before customization default behavior: test string >>> sc.overLoaded = sc.doStuff # Customize >>> sc.overLoaded("test string") do stuff: test string >>> del sc.overLoaded # Revert to default behavior >>> sc.overLoaded("test string") default behavior: test string </code></pre>

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