[Tutor] "Forward" declarations

Simon Brunning SBrunning@trisystems.co.uk
Fri, 18 Aug 2000 09:06:08 +0100

> From:	Danie Roux [SMTP:s9806673@student.up.ac.za]
> How do I use a variable that is only declared later on in the file? Is
> global what I'm looking for? 
> My question then is does 'global' make the variable global within the
> module or across the whole program?
(Disclaimer - I don't know what I'm talking about.)

I don't think that there is any such thing as 'declaring' a variable in
Python - the first time you assign to a variable, it is created. If you try
to refer to a variable that you have not yet assigned to, you get a name

It doesn't matter *what* might happen further down the module, if you have
not yet assigned to a name, you'll get a name error. (Remember, Python is
interpreted, not compiled. Any code that has not yet been executed is just
so much ASCII text.)

Global makes a variable global within a module, but only once the global
statement has been executed.

Simon Brunning
TriSystems Ltd.

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