Adding functions to classes after definition

[Gerard Brunick]

Consider:  A)
 >>> class C(object):
...     pass
...
 >>> def f(*args):
...     print args
...    
 >>> C.f = f
 >>> C.f
<unbound method C.f>
 >>> c=C()
 >>> c.f()
(<__main__.C object at 0x04A51170>,)

And B)

 >>> del c
 >>> C.f = types.MethodType(f, None, C)
 >>> C.f
<unbound method C.f>
 >>> c = C()
 >>> c.f()
(<__main__.C object at 0x04A51290>,)

I don't understand A).  It is my vague understanding, that methods are
really properties that handle binding on attribute access, so B) should
be the "right" way to add a method to a class after definition.  Why does
A show up as a method?  Shouldn't it still just be a function?  Certainly
when you define a class, there is some magic in the __new__ method that
turns functions in the initial dictionary into methods, but does this still
happen for all setattr after that?  Is is possible to set a class attribute
equal to a regular (types.FunctionType) function?

Any references that discuss these issues would be greatly appreciated.

Thanks,
Gerard