Tab before keyword (E274)

There should be only one space before a keyword.

Anti-pattern

In this example there is a tab before the in keyword.

Note: The → character represents a tab.

def func():
    if 1→in [1, 2, 3]:
        print('yep!')

Best practice

Use only one space before the in operator.

def func():
    if 1 in [1, 2, 3]:
        print('yep!')