Question

编辑：谢谢，问题已经回答了！

该程序正常运行，除了它不循环以允许用户玩新游戏。即，在输入太多，太少或完美的变化量之后，程序会问“再试一次（是/否）？：”。但我无法找出它为什么不循环...当它循环时，它不需要包含关于解释游戏的大段落。只是关于“输入加起来的硬币+ + str（数字）+”美分，每行一个。“有什么提示吗？

#Setup

import random
playagain = "y"

#Main Loop

if (playagain == "y"):

    number = random.randint(1,99) #Generation of how many cents
    total = 0 #Running sum of guessed coins.

    print("The purpose of this exercise is to enter a number of coin values")
    print("that add up to a displayed target value. \n")
    print("Enter coins values as 1-penny, 5-nickel, 10-dime,and 25-quarter.")
    print("Hit return after the last entered coin value.\n")
    print("Enter coins that add up to "+str(number)+" cents, one per line.\n")

    while (True):
        if (total == 0):
            word = "first"
        else:
            word = "next"

        guess = str(input("Enter "+str(word)+" number: ")) #Records coin value

        #Entry Validation
        if (guess == ""): #When user is done guessing.
            if (total < number):
                print("Sorry - you only entered "+str(total)+" cents.\n")
                break
            elif (total > number):
                print("Sorry -  total amount exceeds "+str(number)+" cents.\n")
                break
            else:
                print("Correct!")
                break
        elif (int(guess) == 1) or (int(guess) == 5) or (int(guess) == 10) or (int(guess) == 25): 
            total = total + int(guess)        

        else:
            print("Invalid entry")
playagain = str(input("Try again (y/n)?: ")) #BRETT: I can't seem to get this to loop properly.

Answer 1

通过使用break，你完全离开了while循环，从不检查playagain条件。如果你想看看用户是否想要再次播放，请将'playagain'检查放入另一个循环中。

#Setup

import random
playagain = "y"

#Main Loop

while (playagain == "y"):

    number = random.randint(1,99) #Generation of how many cents
    total = 0 #Running sum of guessed coins.

    print("The purpose of this exercise is to enter a number of coin values")
    print("that add up to a displayed target value. \n")
    print("Enter coins values as 1-penny, 5-nickel, 10-dime,and 25-quarter.")
    print("Hit return after the last entered coin value.\n")
    print("Enter coins that add up to "+str(number)+" cents, one per line.\n")

    while (True):
        if (total == 0):
            word = "first"
        else:
            word = "next"

        guess = str(input("Enter "+str(word)+" number: ")) #Records coin value

        #Entry Validation
        if (guess == ""): #When user is done guessing.
            if (total < number):
                print("Sorry - you only entered "+str(total)+" cents.\n")
                break
            elif (total > number):
                print("Sorry -  total amount exceeds "+str(number)+" cents.\n")
                break
            else:
                print("Correct!")
                break
        elif (int(guess) == 1) or (int(guess) == 5) or (int(guess) == 10) or (int(guess) == 25): 
            total = total + int(guess)        

        else:
            print("Invalid entry")
    playagain = str(input("Try again (y/n)?: ")) #BRETT: I can't seem to get this to loop properly.

Answer 2

您将playagain设置为y / n，但如果playagain等于'y'，则代码不会回到开头。尝试将if playagain == "y"转换为while playagain == "y"。这样，如果playagain仍然设置为“y”，它会第一次进入并继续回到开头。

另外，缩进最后一行（playagain = str(....)），使其成为while playagain == "y"循环的一部分。如果不是，则代码将陷入无限循环，因为在while循环内没有更改playagain。

Answer 3

将最后一行缩进到while True行。并将if (playagain == "y"):更改为

while (playagain == "y"):

Answer 4

你的＆＃34;主循环＆＃34;不是循环，它只是一个if语句。另外最好使用raw_input，因为输入将评估您的输入。尝试一下这一点：

playagain = 'y'
#Main loop
while playagain == 'y':
    print "do gamelogic here..."
    playagain = raw_input("Try again (y/n)?: ")

在你的gamelogic中，你可以使用布尔值检查是否需要打印游戏说明：

show_explanation = True
while playagain == 'y':
    if show_explanation:
        print "how to play is only shown once..."
        show_explanation = False

    print "Always do this part of the code"
    ...

    playagain = raw_input("Try again (y/n)?: ")

PYTHON：无法正常循环

4 个答案: