Question

我不确定以下为什么不起作用：

def main():
    userInputs()
    print(firstColour)

def userInputs():
    validColours = ['red', 'green', 'blue', 'yellow', 'magenta','cyan']
    while True:
        firstColour = input('Enter the 1st colour: ')
        secondColour = input('Enter the 2nd colour: ')
        thirdColour = input('Enter the 3rd colour: ')
        fourthColour = input('Enter the 4th colour: ')
        if firstColour in validColours:
             if secondColour in validColours:
                if thirdColour in validColours:
                    if fourthColour in validColours:
                        break
        else:
            print('Invalid colours.Enter the colours again between red, green, blue, yellow, magenta, cyan')
        return firstColour, secondColour, thirdColour, fourthColour

我认为如果我调用主函数，它会打印我作为firstColour输入的内容吗？

Answer 1

如果要打印第一种颜色，请尝试以下操作：

def main():
    firstColour, secondColour, thirdColour, fourthColour = userInputs()
    print(firstColour)

当你在函数中的python中返回多个值时，它会将它们打包成一个名为＆＃34; tuple＆＃34;这是一个简单的值列表。你必须＆＃34;解包＆＃34;他们是为了使用它们。

您的userInputs函数中似乎还存在逻辑错误。你的返回函数缩进太多，这使得它总是在第一次尝试后返回，而不是重试。

def userInputs():
    validColours = ['red', 'green', 'blue', 'yellow', 'magenta','cyan']
    while True:
        firstColour = input('Enter the 1st colour: ')
        secondColour = input('Enter the 2nd colour: ')
        thirdColour = input('Enter the 3rd colour: ')
        fourthColour = input('Enter the 4th colour: ')
        if firstColour in validColours:
             if secondColour in validColours:
                if thirdColour in validColours:
                    if fourthColour in validColours:
                        break
        else:
            print('Invalid colours.Enter the colours again between red, green, blue, yellow, magenta, cyan')
    return firstColour, secondColour, thirdColour, fourthColour

Answer 2

在python中，您将返回所谓的元组。如果您只想返回firstColour，则只需调整逻辑即可为foundColour分配最后找到的颜色，然后return foundColour

有关元组的更多信息：https://docs.python.org/2/tutorial/datastructures.html#tuples-and-sequences

Answer 3

您没有使用您返回的值：

return firstColour, secondColour, thirdColour, fourthColour

您将返回4个变量，但不使用它们

userInputs()

用以下内容替换上述内容：

firstColour, secondColour, thirdColour, fourthColour = userInputs()

如何将return语句与字符串一起使用？ - Python

3 个答案: