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python - ValueError 验证循环

问题描述

在上了一门教我们伪代码的课程后，我开始使用 Python。如果用户输入小数而不是整数，我如何进行验证循环以继续该功能？在当前状态下，当用户输入超出可接受范围的数字时，我已经让它识别，但如果用户输入十进制数字，它就会崩溃。是否有另一个可以识别小数的验证循环？

def main():
    again = 'Y'
    while again == 'y' or again == 'Y':
        strength_score = int(input('Please enter a strength score between 1 and 30: '))

        # validation loop
        while strength_score < 1 or strength_score > 30 :
            print ()
            print ('Error, invalid selection!')
            strength_score = int(input('Please enter a whole (non-decmial) number between 1 and 30: '))

        # calculations
        capacity = (strength_score * 15)
        push = (capacity * 2)
        encumbered = (strength_score * 5)
        encumbered_heavily = (strength_score * 10)

        # show results
        print ()
        print ('Your carrying capacity is' , capacity, 'pounds.')
        print ('Your push/drag/lift limit is' , push, 'pounds.')
        print ('You are encumbered when holding' , encumbered, 'pounds.')
        print ('You are heavyily encumbered when holding' , encumbered_heavily, 'pounds.')
        print ()

        # technically, any response other than Y or y would result in an exit. 
        again = input('Would you like to try another number? Y or N: ')
        print ()
    else:
        exit()

main()

标签： python

解决方案

取决于您希望行为是什么：

  1. 如果要接受非整数，只需使用float(input()). 如果您想接受它们但将它们转换为整数，请使用int(float(input()))截断或round(float(input()))舍入到最接近的整数。

  2. 如果要打印错误消息并提示输入新号码，请使用 try-catch 块：

    try:
    strength_score = int(input('Please enter a strength score between 1 and 30: '))
except ValueError:
    again = input("Invalid input, try again? Y / N")
    continue # skip the rest of the loop

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