Test for membership should be 'not in' (E713)

Tests for membership should use the form x not in the_list rather than not x in the_list. The former example is simply more readable.

Anti-pattern

my_list = [1, 2, 3]
if not num in my_list:
    print(num)

Best practice

my_list = [1, 2, 3]
if num not in my_list:
    print(num)

Additional links

• https://www.python.org/dev/peps/pep-0008/#programming-recommendations