Python Feature Request: Explicit variable declarations

[nikolas pontikos]

samjnaa at gmail.com wrote:
> Hello. Please tell me whether this feature request is sane (and not
> done before) for python so it can be posted to the python-dev mailing
> list. I should say first that I am not a professional programmer with
> too much technical knowledge.
> 
> I would like to have something like the "option explicit" statement in
> Visual Basic which turns on C-like checking for declaration of
> variables. This is highly helpful for people who are coming from C/C+
> +, for people who are learning programming using Python, and even
> professionals, since this helps prevent typo errors like:
> 
> sunlognitude = sunlongitude + 180.0
> 
> where the user has inadvertantly typed "g" before "n" and will later
> wonder why his application is not working as expected.
> 

Just as a side-note, if you used a+=1 instead of a=a+1 then you wouldn't 
have this problem.
Languages like Perl and VB need a strict mode because they will 
auto-vivify variable for you.  I.e. they will bring variables to life 
with defined or undefined values if you use them in a l-value (left hand 
side of an assignment) without having declared them prior.  If you do 
that in Python you get an exception.