Python `if x is not None` or `if not x is None`?
- by orokusaki
I've always thought of the if not x is None version to be more clear, but Google's style guide implies (based on this excerpt) that they use if x is not None. Is there any minor performance difference (I'm assuming not), and is there any case where one really doesn't fit (making the other a clear winner for my convention)?*
*I'm referring to any singleton, rather than just None.
...to compare singletons like
None. Use is or is not.
