Test for Null values Field Calculator

Discussion created by AdamCox on Feb 7, 2013
Latest reply on Feb 8, 2013 by fallingdog
Ok, I just finished reading a bunch of threads on this, but need to double check this issue.  I want to put something like this
def i(x):
  if x is None:
    return "Used to be Null"
    return x

into the code-block, but I've tried all sorts of variations that have been suggested, x == None, x == "", if not x, but nothing has produced any change in the values.

Am I missing something, or is this just not going to work and I'll have to use update cursors to perform operations like this?

I'm using 10.0 SP5.

Thank you!