Semi-newbie, rolling my own __deepcopy__

[Steven Bethard]

Michael Spencer wrote:
> BTW, as I mentioned in a previous comment, I believe this would be more 
> plainly written as type(self).__new__(), to emphasize that you are 
> constructing the object without initializing it.  (There is a 
> explanation of __new__'s behaviour at 
> http://www.python.org/2.2/descrintro.html#__new__).

There is also now documentation in the standard location:

http://docs.python.org/ref/customization.html

And just to clarify Michael's point here, writing this as __new__ means 
that __init__ is not called twice:

py> class C(object):
...     def __new__(cls):
...         print '__new__'
...         return super(C, cls).__new__(cls)
...     def __init__(self):
...         print '__init__'
...
py> c = C()
__new__
__init__
py> c2 = type(c)(); c2.__init__()
__new__
__init__
__init__
py> c3 = type(c).__new__(C); c3.__init__()
__new__
__init__

But definitely check the docs for more information on __new__.  Some of 
the interworkings are kind of subtle.

STeVe