Overriding special methods on an instance

Question

I hope someone can answer this that has a good deep understanding of Python :)

Consider the following code:

>>> class A(object):
...     pas         


        

Answer 1

Python doesn't call the special methods, those with name surrounded by __ on the instance, but only on the class, apparently to improve performance. So there's no way to override __repr__() directly on an instance and make it work. Instead, you need to do something like so:

class A(object):
    def __repr__(self):
        return self._repr()
    def _repr(self):
        return object.__repr__(self)

Now you can override __repr__() on an instance by substituting _repr().