当抛硬币的整个过程完成后，无法计算出如何使python抛硬币程序循环回到某个点

Question

我的头撞在墙上已经有几个小时了，我想弄清楚这个问题，所以我非常感谢你的帮助。我要做的是在一个Y/N问题的Y输入上循环程序，特别是当Y被输入时，我希望它以示例输出中所示的方式进行反应。在

这是我的代码：

import random
def main():
    name = eval(input("Hello user, please enter your name: "))
    print("Hello", name ,"This program runs a coin toss simulation")
    yn = input("Would you like to run the coin toss simulation?(Y/N):")
    if yn == Y:

    elif yn == N:
        print("Ok have a nice day!")

    heads = 0
    tails = 0
    count = tails + heads
    count = int(input("Enter the amount of times you would like the coin to     flip: "))
    if count <= 0: 
        print("Silly rabbit, that won't work")
    while tails + heads < count:
        coin = random.randint(1, 2)
        if coin ==1:

            heads = heads + 1
        elif coin == 2:

            tails = tails + 1
    print("you flipped", count , "time(s)")
    print("you flipped heads", heads , "time(s)")
    print("you flipped tails", tails , "time(s)")
main()

下面是我要查找的示例输出：

^{pr2}$

Answer 1

要多次运行抛硬币模拟，可以将其放入while循环中。在

您的if yn == Y:测试将不起作用，因为您还没有定义变量Y，所以当Python尝试执行该行时，会得到一个NameError。您实际应该做的是根据字符串测试yn的值。在

我对你的代码做了一些其他的小调整。我去掉了那个潜在危险的eval函数调用，你不需要它。我还创建了一个循环来请求所需的翻转计数；当count是一个正数时，我们就中断循环。在

import random

def main():
    name = input("Hello user, please enter your name: ")
    print("Hello", name , "This program runs a coin toss simulation")
    yn = input("Would you like to run the coin toss simulation?(Y/N): ")
    if yn != 'Y':
        print("Ok have a nice day!")
        return

    while True:
        heads = tails = 0
        while True:
            count = int(input("Enter the amount of times you would like the coin to flip: "))
            if count <= 0: 
                print("Silly rabbit, that won't work")
            else:
                break

        while tails + heads < count:
            coin = random.randint(1, 2)
            if coin ==1:
                heads = heads + 1
            else:
                tails = tails + 1

        print("you flipped", count , "time(s)")
        print("you flipped heads", heads , "time(s)")
        print("you flipped tails", tails , "time(s)")

        yn = input("Would you like to run another coin toss simulation?(Y/N): ")
        if yn != 'Y':
            print("Ok have a nice day!")
            return

main()

---

这段代码是为python3编写的。在Python2上，您应该使用raw_input代替input，并且还应该将

从未来导入打印功能

在脚本的顶部，这样您就得到了python3print函数，而不是旧的python2print}\u语句。在

---

可以对该代码进行一些改进。特别是，它应该处理为计数提供的非整数。如果输入错误，这个版本就会崩溃。要了解如何修复此问题，请参见Asking the user for input until they give a valid response。在

Answer 2

我想你应该说在第6行if yn == 'Y'，而不是if yn == Y。将Y视为变量，而它实际上是输入中的字符串。在