Testing the existnace of variable

Hi,

I have a script in which I'd like to test whether or not a particular variable has been defined or not.

The php equivalent would be something like this:

if !$MyVariable
{$MyVariable = "Hello World";}

else
{echo $MyVariable;}

What is the equivalent syntax in Python? Can't seem to find anything in any of the documentation I have.

Thanks, NICK

Hello,
You need to assign variables in Python before you can use them. This is
good programming practice. You can re-define variables later eg:

#!/usr/bin/env python
def main():
testVar=None
if (not testVar):
testVar = "Hello World"
print testVar
testVar = 3
print testVar
if __name__ == "__main__":
main()

prints:
Hello World
3

But, I strongly advise you to try to avoid doing this. It makes code difficult to understand and maintain. I suggest you initialise your variables before use.

Hope that helps,
Adil

Thanks for that

NICK

To answer your question directly...

One way to test the existence of a variable would be:



Best,
parker