有问题与python输入

Question

我对编程相当陌生，发现了一个让你制作游戏的练习。基本上，程序要求3个输入：停止、启动和退出。启动使汽车启动，停止使汽车停止，退出是不言自明的。但是，如果你在汽车已经启动时输入启动，它会告诉你汽车已经启动，依此类推。然而，当我将输入输入到终端时，没有显示任何内容。谁能告诉我我做错了什么？

这是我的密码：

started = False

carstate = str(input())

while carstate != "exit":
    if carstate == "start":
        if started == False:
            started == True
            print("Car has started... ready to go!")
        if started == True:
            print("Car has already started")
    elif carstate == "stop":
        if started == False:
            print("Car is already stopped!")
        if started == True:
            started == False
            print("Car is stopped")

if carstate == "exit":
    sys.exit()
if carstate == "help":
    print("Start - starts the car")
    print("Stop - stops the car")
    print("Exit - exits the game")

Answer 1

您当前的代码很可能会卡在time循环中。如果您通过输入start进入循环，您将不会打印任何内容，也没有任何机会更改该内容。

另一个注意事项是对exit和help的两个附加状态检查。我会在主while循环中包含这些（或至少是帮助一个）。

在两种情况下，我确信您希望使用赋值=，而不是等式检查=。还有其他一些清理工作：-）

这样做应该可以：

started = False

carstate = ""  # initialize empty, we will ask for input at every iteration

while carstate != "exit":
    carstate = input()  # ask what we want to do next
    if carstate == "start":
        if started == False:
            started = True  # here you want to make an assignment (use '=' not '==')
            print("Car has started... ready to go!")
        elif started == True:  # change to "elif", so it avoids double prints
            print("Car has already started")

    elif carstate == "stop":
        if started == False:
            print("Car is already stopped!")
        elif started == True:  # change to "elif", so it avoids double prints
            started = False  # here you want to make an assignment (use '=' not '==')
            print("Car is stopped")

    elif carstate == "help":
        print("Start - starts the car")
        print("Stop - stops the car")
        print("Exit - exits the game")

if carstate == "exit":
    sys.exit()

您可以在这里尝试：https://onlinegdb.com/S1gJ6lRGL

Answer 2

您在开始时要求用户输入，然后执行同时循环。因为你不会在这段时间再次要求不同的动作，所以它循环着“汽车开始了...准备出发！”。你必须在循环内做另一个"输入（）"

Answer 3

欢迎来到StackOverflow！

这里的第一个问题是，由于carstate=input（）不在while循环中，因此程序只调用用户输入一次。要多次请求用户输入，应将其放在如下位置：

carstate = ""

while carstate != "exit":
    carstate = input()

    # ...

因此，程序将继续要求用户输入。

第二个问题是=和=之间的区别=用于为变量赋值，而=用于将某个值与变量进行比较。所以，当你说started==True时，你真的应该使用=。

此外，您应该将帮助块也放置在同时循环中，否则它将永远不会执行。

所以最后的代码应该是这样的：

import sys

started = False

carstate = ""

while carstate != "exit":
    carstate = input()
    if carstate == "start":
        if started == False:
            started = True
            print("Car has started... ready to go!")
        elif started == True:
            print("Car has already started")
    elif carstate == "stop":
        if started == False:
            print("Car is already stopped!")
        elif started == True:
            started = False
            print("Car is stopped")
    elif carstate == "help":
        print("Start - starts the car")
        print("Stop - stops the car")
        print("Exit - exits the game")

if carstate == "exit":
    sys.exit()

工作示例