Sion Arrowsmith wrote: > stef mientki <[EMAIL PROTECTED]> wrote: > >> def Run (): >> print X <=== UnboundLocalError: local variable >> 'X' referenced before assignment >> X = X + 1 >> >> Why do I get the error ? >> Printing isn't assigning anything or am I missing something. >> Now if I remove "X = X + 1" I don't get an error ??? >> > > Several people have already explained the scoping rules acting > here, but let's just look at how that error message is telling > you everything you need to know to fix the problem. > > "local variable 'X' referenced before assignment" > > "local variable 'X'" immediately tells you that the 'X' in > question is not your global 'X'. > > "referenced before assignment": well, 'print X' is surely a > reference to 'X', and 'X = X + 1' is an assignment to it, > and 'print X' appears before 'X = X + 1'. That this is the > key you have confirmed experimentally. > > The question to ask here is "Why does Python think 'X' is > local?" Everything else is answered by the error message. > > Thanks guys, I beginning to see the light again, and if X is mutual the story is completely different, I still have to get used to these differences.
cheers, Stef Mientki -- http://mail.python.org/mailman/listinfo/python-list
