spacepaste

>>> class A(object):
... def __eq__(self, other):
... raise IndexError
... def __hash__(self):
... return hash(1)
...
>>> d = {A(): 3}
>>> d[1]
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in __eq__
IndexError
>>>