[Python-Dev] Re: redefining is (original) (raw)

Barry Warsaw barry at python.org
Fri Mar 19 14:16:52 EST 2004

On Fri, 2004-03-19 at 13:54, Casey Duncan wrote:

The problem is that 'obj == None' is not the assertion you want to make usually. 'obj == None' means "obj claims it is equal to None", whereas 'obj is None' means 'obj is the None object'. The latter is a much more stringent assertion than the former which relies on the particular implementation of obj.

Exactly.

-Barry

More information about the Python-Dev mailing list