How do I check if a variable exists?

Question

I want to check if a variable exists. Now I\'m doing something like this:

try:
   myVar
except NameError:
   # Do something.

Are there othe

Answer 1

Using try/except is the best way to test for a variable's existence. But there's almost certainly a better way of doing whatever it is you're doing than setting/testing global variables.

For example, if you want to initialize a module-level variable the first time you call some function, you're better off with code something like this:

my_variable = None

def InitMyVariable():
  global my_variable
  if my_variable is None:
    my_variable = ...