[Python-Dev] Re: would warnings be appropriate for probably-misused global statements? (original) (raw)

Jeremy Hylton jeremy@alum.mit.edu
Thu, 7 Nov 2002 11:40:40 -0500

"GvR" == Guido van Rossum <guido@python.org> writes:

GvR> Global outside a function would seem easy to detect (at least GvR> as easy as return outside a function), but you need to be GvR> careful: in a string passed to the exec statement, one could GvR> have distinct locals and globals, and then 'global x' outside a GvR> function would make sense. Also, 'global x' makes sense inside GvR> a class statement.

IIRC I added a warning/error to the compiler about global at the module level, but later removed it because it was too hard (impossible?) to determine whether a block of code was being compiled to exec or being compiled for the body of a module. Anyone interested could check the CVS log for compile.c.

GvR> But I'm not excited about this. A similar amount of analysis GvR> can discover assigning to a variable that's not used. Isn't GvR> that more useful? Using a name that's not defined anywhere. GvR> Etc. There are tons of these things. PyChecker watches for GvR> all of them. I'd prefer to make a project out of integrating GvR> PyChecker functionality into Python, eventually, rather than GvR> attacking random things one at a time

I didn't check myself, because I agree with you on this point.

Jeremy