1 >>>class Friendly:
   2 ... def hello(self):
   3 ... print 'Hello'
   4 ...
   5 >>> class Person:
   6 ... pass
   7 ...
   8 >>> p = Person()
   9 >>> Person.__bases__ += (Friendly,)
  10 >>> p.hello()
  11 Hello

   1 import types
   2 def MixIn(pyClass, mixInClass, makeAncestor=0):
   3    if makeAncestor:
   4      if mixInClass not in pyClass.__bases__:
   5         pyClass.__bases__ = (mixInClass,) + pyClass.__bases__
   6    else:
   7      # Recursively traverse the mix-in ancestor
   8      # classes in order to support inheritance
   9      baseClasses = list(mixInClass.__bases__)
  10      baseClasses.reverse()
  11      for baseClass in baseClasses:
  12         MixIn(pyClass, baseClass)
  13      # Install the mix-in methods into the class
  14      for name in dir(mixInClass):
  15         if not name.startswith('__'):
  16         # skip private members
  17            member = getattr(mixInClass, name)
  18            if type(member) is types.MethodType:
  19                member = member.im_func
  20            setattr(pyClass, name, member)