gistfile1.txt

In [11]: class Counter():
    ...:   def __init__(self):
    ...:     self.__counter = 0
    ...:
    ...:   def count(self, increment):
    ...:     self.__counter += increment
    ...:     return self.__counter
    ...:
    ...:

In [12]: c = Counter()

In [13]: c.count(1)
Out[13]: 1

In [14]: c.count(1)
Out[14]: 2

In [15]: c.count(1)
Out[15]: 3