abusing python functions

gistfile1.txt

>>> def foo():
...     foo.x = 0
...     foo.total = lambda: foo.x
...     def add(x):
...         foo.x = foo.x + x
...         return foo
...     foo.add = add
... 
>>> foo()
>>> foo.total()
0
>>> foo.add(3).add(5).total()
8