Unexpected spaces around keyword / parameter equals (E251)

There should be no spaces before or after the = in a function definition.

Anti-pattern

def func(key1 = 'val1',
         key2 = 'val2'):
    return key1, key2

Best practice

def func(key1='val1',
         key2='val2'):
    return key1, key2

Additional links

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