self is the class instance that the bound function being called belongs to. This example should illustrate a bit.
class Foo(object): def __init__(self, value): self.value = value # so the Foo instance now has an attribute, value def get_value(self): return self.value # This gets the previously-set value attribute of the Foo instance bar = Foo(42) baz = Foo('101010') print bar.get_value() #Note that the self argument is implicit since this is a bound method. print print baz.get_value() The output is (or should be, as this is untested): 42 101010 -- http://mail.python.org/mailman/listinfo/python-list