Brackets

scratch3.py

def is_correct_bracket(text):
    a = ''
    while True:
        a = text
        text = text.replace('()', '')
        if len(text.replace('()', '')) == len(a):
            break
    if len(text) == 0:
        return True
    else:
        return False

txt = input()

# вызываем функцию
print(is_correct_bracket(txt))