class A(object):

        def __init__(self):

                self.a = 0

        def __iter__(self):

                return self

        def next(self):

                self.a = self.a + 1

                if self.a > 10:

                        self.a = 0

                        raise StopIteration();

                return self.a

>>> import collections

>>> isinstance(a, collections.Iterable)

True

>>> import h

>>> a = h.A()

>>> for x in a:

...     print x,

...

1 2 3 4 5 6 7 8 9 10

>>> l = list('sdfsd')

>>> l

['s', 'd', 'f', 's', 'd']

>>> l.extend(a)

>>> l

['s', 'd', 'f', 's', 'd', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]