[Python-Dev] Making None a keyword
M.-A. Lemburg
mal@lemburg.com
Fri, 26 Apr 2002 09:58:36 +0200
Guido van Rossum wrote:
>
> I'd like to make None a keyword. This prevents dumb users from
> assigning to it and screwing themselves, and can cause a slight
> speedup because using None avoids two dict lookups.
>
> - Any objections?
+1 but only if you use the standard mechanism for this:
warnings in 2.3, SyntaxError in 2.4.
> - Can somebody help me implement this? I've got the parser changes
> ready, but not the compiler changes.
>
> Believe it or not, Zope3 contains code that will break with this
> change: there are functions with a default argument of the form
> None=None as a speedup hack. I think this is an argument *for* the
> change. :-)
Zope3 is not the only software using these kind of hacks
to work around the builtins lookups.
--
Marc-Andre Lemburg
CEO eGenix.com Software GmbH
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