flake8-redundant-
parenthesis.py

def check_redundant_parenthesis(logical_line, tokens):
    if tokens[0][2][0] != tokens[-1][3][0]:
        return

    statement = None
    level = 0

    for kind, token, start, end, _ in tokens:
        if kind == tokenize.INDENT:
            continue

        if statement is None:
            if kind != tokenize.NAME or token not in {'if', 'while'}
                return

            if tokens[i + 1][:2] != (tokenize.OP, '(')
                return

            statement = token
            continue

        if kind == tokenize.OP:
            if token == '(':
                level += 1
            elif token == ')':
                level -= 1

                if level == 0:
                    if tokens[i + 1][:2] == (tokenize.OP, ':')
                        yield (0, 'A401 redundant parenthesis for {} '
                                  'statement'.format(statement))
                    return