Why does __init__ not get called?

[Steven Bethard]

Rob Conner wrote:
> By chance... does anyone know, if I wrote a class, and just wanted to
> override __new__ just for the fun of it. What would __new__ look like
> so that it behaves exactly the same as it does any other time.

Simple:

class C(object):
     def __new__(cls, *args, **kwargs):
         return super(C, cls).__new__(cls, *args, **kwargs)

Basically, you're calling object's __new__ method, which in CPython does 
something like mallocing the appropriate amount of memory, setting the 
__class__ attribute of the object, etc.

Note that __new__() doesn't call __init__().  Both __new__() and 
__init__() are called individually by the metaclass.  For new-style 
classes, "type" is the metaclass, and it's  __call__() method looks 
something like:

def __call__(cls, *args, **kwargs):
     obj = cls.__new__()
     if not isinstance(obj.__class__, cls):
         return obj
     obj.__class__.__init__(obj, *args, **kwargs)
     return obj

(But see Objects/typeobject.c:409 for the full gory details.)

STeVe