Assigning to a random attribute in a method

demo.txt

$ python
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> class C(object):
...   def foo(self):
...     self.bar = 42
... 
>>> c = C()
>>> c.foo()
>>> c.bar
42