Question

我必须让用户输入一个整数，但它不能是负数。但是，每当我测试程序时，如果输入一个负数，它就不允许它。如果我第二次输入负数，它将允许它。我知道为什么，但我不知道我可以用什么替代品。以下是它的打印方式：

What would you like x to be? -5
Sorry, the number of juveniles must be positive. Please try again.
What would you like x to be? -5
What would you like y to be? -9
Sorry, the number of adults must be positive. Please try again.
What would you like y to be? -9
What would you like z to be? -10
Sorry, the number of seniles must be positive. Please try again. 
What would you like z to be? -10

这是我的代码：

x = int(input("What would you like x to be? "))
if x<0:
    print("Sorry, x must be positive. Please try again.")
    x = int(input("What would you like x to be? "))
y = int(input("What would you like y to be? "))
if y<0:
    print("Sorry, y must be positive. Please try again.")
    y = int(input("What would you like y to be? "))
z = int(input("What would you like z to be? "))
if z<0:
    print("Sorry, z must be positive. Please try again. ")
    z = int(input("What would you like z to be? "))

我看了看周围的地方，但找不到合适的替代品。请帮忙。

Answer 1

在这些方面尝试一些事情

while(true):
    x = int(input("What would you like x to be? "))
    if(x > 0):
        break;

Answer 2

if只会检查一次。只需将if语句替换为while：

x = int(input("What would you like x to be? "))
while x<0:
    print("Sorry, x must be positive. Please try again.")
    x = int(input("What would you like x to be? "))
y = int(input("What would you like y to be? "))
while y<0:
    print("Sorry, y must be positive. Please try again.")
    y = int(input("What would you like y to be? "))
z = int(input("What would you like z to be? "))
while z<0:
    print("Sorry, z must be positive. Please try again. ")
    z = int(input("What would you like z to be? "))

如何在python中允许输入超过一定数量

2 个答案: