On Tue, 15 Nov 2005 21:53:23 +1100, Steven D'Aprano <[EMAIL PROTECTED]> wrote:
[...]
>It isn't always appropriate or necessary to define "constants" (and I
>sometimes wish that Python would enforce assign-once names), but they can
>help avoid some silly mistakes.
(As I'm sure you know) you can have "assign-once" names
if you are willing to spell them with a dot ;-)
>>> N = type('',(),{'name':property(lambda _:42)})()
>>> N.name
42
>>> N.name = 43
Traceback (most recent call last):
File "<stdin>", line 1, in ?
AttributeError: can't set attribute
One could also write a more efficient write-once guarantee for function scope
using a decorator that munges byte code to guarantee it.
Or one could write a custom import that guarantees it for module scope.
Or one could change the language ;-)
Regards,
Bengt Richter
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