double underscore attributes?

[LocaWapp]

Hi Bob,
see this my example:

>>> class A:
...     def __add__(a,b):
...             print a,b
...
>>> a = A()
>>> b = A()
>>> a + b
<__main__.A instance at 0x80c5a74> <__main__.A instance at 0x80c6234>
>>>