虽然循环测试

Question

我没有得到这个Python代码所需的结果。需要帮忙。

当您输入满足条件的字符串时，while循环应该停止。

代码：

x = input("Enter input: ") 

while (int(x[3]) != 1 or int(x[3]) != 2): 
    print("The fourth character must be a 1 or 2") 
    x = input("Enter input again: ") 

Answer 1

一个数量总是不等于1或2，您可能需要使用and：使用not in

x = input("Enter input: ") 

while int(x[3]) != 1 and int(x[3]) != 2: 
    print("The fourth character must be a 1 or 2") 
    x = input("Enter input again: ") 

是更具可读性：

x = input("Enter input: ") 

while int(x[3]) not in (1, 2): 
    print("The fourth character must be a 1 or 2") 
    x = input("Enter input again: ") 

如果您想要更容错的方式，请与字符串比较：

while True: 
    x = input("Enter input: ") 
    if x[3:4] in ('1', '2'): 
     break 
    print("The fourth character must be a 1 or 2.")