读取stdin for python TDD

Question

我想学习如何使用Python 2 TDD读取标准输入，但我仍然遇到ZNEC运行时错误，并且没有解决方法帮助我通过。这是我最近的功能和测试输入（）：

def parens_balance(line):
    parensonly = ''.join(char for char in line if char == '(' or char == ')')
    parenscount = 0
    for i in parensonly: 
        if i == '(':
            parenscount +=1 
        elif i == ')':
            parenscount +=1
    if parenscount % 2 == 0:
        print('{} {}'.format('Y', parensonly))
    else:
        print('{} {}'.format('N', parensonly))

line = input()
print(parens_balance(line))

测试用例为((1+2) * (3-4))或(1+2)*3)+5/8)