6. Use is None for None checks

Use is None and is not None for None checks.

None is a singleton, so identity is the right concept here, not equality. Using is also avoids surprising behavior from user-defined __eq__ methods that can make == None behave in unexpected ways.

6.1. Don’t do this

if result == None:
    print('missing')

6.2. Do this

if result is None:
    print('missing')