Determine if the special characters in the incoming string are valid parenthetical expressions

parenthetic_expr.py

def is_valid(s: str) -> bool:
    """
    Determine if the special characters in the incoming string are valid parenthetical expressions
    :param s:
    :return:
    """
    # ( [ ( ) ]
    brackets_q = []
    spec_lhs, spec_rhs = ['(', '{', '['], [')', '}', ']']

    for c in s:
        if c in spec_lhs:  # F
            brackets_q.append(c)  # ( [X (X

        if c in spec_rhs:  # F F F T)  T
            if not len(brackets_q):
                return False

            last_bracket = brackets_q.pop()  # ( [
            idx_match = spec_lhs.index(last_bracket)  # 0 2

            if c != spec_rhs[idx_match]:  # F F
                return False

    if len(brackets_q):  # T - ( remains
        return False

    return True


if __name__ == '__main__':
    x = is_valid("(]")
    print('isvalid:', x)

    x = is_valid("()")
    print('isvalid:', x)

    x = is_valid("([)")
    print('isvalid:', x)

    x = is_valid("([])")
    print('isvalid:', x)

    x = is_valid("([]{})")
    print('isvalid:', x)

    x = is_valid("( [ ( ) ]")
    print('isvalid:', x)

    x = is_valid("{{{{{{{{{{{{{{{( [ ( ) ] )}}}}}}}}}}}}}}}")
    print('isvalid:', x)

    x = is_valid("{{{{{{{{{{{{{{{( [ ( ) ] )}}}    ]    }}}}}}}}}}}}")
    print('isvalid:', x)

    x = is_valid("{}[]{}[]{}[]{}[]{}[]{}[]")
    print('isvalid:', x)

    x = is_valid("({}[])[{}[]]((({}[]{}[]{}[]{}[])))")
    print('isvalid:', x)