In [1]: class Foo(object):
   ...:         class Bar(object):
   ...:             def __init__(self):
   ...:                 self.str = "gnarf"
   ...:     def __init__(self):
   ...:             self.str = "point"
   ...: 

In [2]: b = Foo.Bar()

In [3]: f = open("test","w+")

In [4]: import pickle as P

In [5]: p = P.Pickler(f)

In [6]: p.dump(b)
---------------------------------------------------------------------------
<class 'pickle.PicklingError'>            Traceback (most recent call last)

/home/cers/projects/Facebook/<ipython console> in <module>()

/home/cers/projects/Facebook/pickle.py in dump(self, obj)
    222         if self.proto >= 2:
    223             self.write(PROTO + chr(self.proto))
--> 224         self.save(obj)
    225         self.write(STOP)
    226 

/home/cers/projects/Facebook/pickle.py in save(self, obj)
    329 
    330         # Save the reduce() output and finally memoize the object
--> 331         self.save_reduce(obj=obj, *rv)
    332 
    333     def persistent_id(self, obj):

/home/cers/projects/Facebook/pickle.py in save_reduce(self, func, args, state, listitems, dictitems, obj)
    399         else:
    400             save(func)
--> 401             save(args)
    402             write(REDUCE)
    403 

/home/cers/projects/Facebook/pickle.py in save(self, obj)
    284         f = self.dispatch.get(t)
    285         if f:
--> 286             f(self, obj) # Call unbound method with explicit self
    287             return
    288 

/home/cers/projects/Facebook/pickle.py in save_tuple(self, obj)
    560         write(MARK)
    561         for element in obj:
--> 562             save(element)
    563 
    564         if id(obj) in memo:

/home/cers/projects/Facebook/pickle.py in save(self, obj)
    284         f = self.dispatch.get(t)
    285         if f:
--> 286             f(self, obj) # Call unbound method with explicit self
    287             return
    288 

/home/cers/projects/Facebook/pickle.py in save_global(self, obj, name, pack)
    746             raise PicklingError(
    747                 "Can't pickle %r: it's not found as %s.%s" %
--> 748                 (obj, module, name))
    749         else:
    750             if klass is not obj:

<class 'pickle.PicklingError'>: Can't pickle <class '__main__.Bar'>: it's not found as __main__.Bar