«

I need an if statement to test if a variable exists in a pyton script

eg. if var1 exists:
do this
else:
do this

>>>>> "lamar" == lamar air <> writes:

lamar> I need an if statement to test if a variable exists in a
lamar> pyton script eg. if var1 exists: do this else: do this --


try: x
except NameError:
# x doesn't exist, do something
else:
# x exists, do something else

lamar_air wrote:

>I need an if statement to test if a variable exists in a pyton script
>
>eg. if var1 exists:
> do this
> else:
> do this
>
If it's in a dictionary you can do this: var1.get('key','not found')

( just learned that all of 2 minutes ago ;] )

[Graham Breed]

> lamar_air wrote:
> > I need an if statement to test if a variable exists in a pyton script

> locals().has_key('var1')

The above could also be written:

'var1' in locals()

However, whenever I need to test this (the need is rather unusual), instead
of `if', I prefer writing:

try:
var1
except NameError:
pass # `var1' does not exist
else:
pass # `var1' exists

--
François Pinard http://www.iro.umontreal.ca/~pinard