checking whether a var is empty or not
peufeu at free.fr
Fri Jul 30 08:44:05 CEST 2004
This smells like PHP to me...
if var is not None:
if var has not been assigned, it raises an exception.
if var has been assigned, it contains a value which can be None or
This is different from PHP where you can't know if a variable exists or
not, because a non-existent variable will contain null if you check it,
and putting null in a variable is like deleting it, but noone knows
because there's no way of checking if a variable really exists, etc.
> Are these equivelent? Is one approach prefered over the other
> #check to see if var contains something... if so proceed.
> if var is not None:
> #check to see if var is empty... if so prompt user again.
> if not var:
> print "Please specify the amount."
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