如何在 n 次迭代后停止 while 循环？

Question

我正在学习 python 并且我正在尝试创建具有两个难度级别的猜谜游戏：简单（尝试 10 次）和困难（尝试 5 次）。我的代码运行良好，但我需要强制 while 循环在困难级别尝试 5 次和简单级别尝试 10 次后停止询问猜测。但是，使用我的代码我没有达到我的目标，因为 while 循环在 n 变量 < 5 或 10 之后不会停止。我如何使用下面的代码达到这个目标：

from random import *

def levels():
  user_level=input('Type E for easy level and D for difficult level: ')
  if user_level=='e':
    easy_level()
  else:
    difficult_level()

number=randint(1,100)

def difficult_level():
  n= 0
  while n < 5:
    user_number=int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again=input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
        break
  print('Sorry, no more attempts :(')


def easy_level():
  n= 0
  while n < 10:
    user_number=int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again=input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
         break
  print('Sorry, no more attempts :(')


levels()

Answer 1

您似乎忘记在循环中递增 n，因此 n 始终 = 0。通常你在循环开始或循环结束时增加你的“tracker”变量。 python 的递增可以用 n += 1.

完成

Answer 2

您需要在每次迭代后递增 n，方法是重新分配 n（例如 n = n + 1），或使用 += 运算符，如下所示：

from random import *

def levels():
  user_level=input('Type E for easy level and D for difficult level: ')
  if user_level=='e':
    easy_level()
  else:
    difficult_level()

number=randint(1,100)

def difficult_level():
  n= 0
  while n < 5:
    user_number=int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again=input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
        break

    n += 1 # increment n after each iteration

  print('Sorry, no more attempts :(')


def easy_level():
  n= 0
  while n < 10:
    user_number=int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again=input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
         break

    n += 1 # increment n after each iteration

  print('Sorry, no more attempts :(')


levels()

Answer 3

像这样使用 for 循环可能更容易：

def levels():
  easy_turns = 5
  hard_turns = 10
  user_level=input('Type E for easy level and D for difficult level: ')
  if user_level=='e':
    play(easy_turns)
  else:
    play(hard_turns)

def play(turns):
  for _ in range(turns):
    user_number=int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again=input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
         break
  print('Sorry, no more attempts :(')

一个好的经验法则是，如果您两次使用相同的代码，请将其放入一个函数中。随着时间的推移，它肯定会失去同步，然后你会想知道为什么“简单”有效，而“困难”却做了一些奇怪的事情（或一些变体）。

Answer 4

简短的回答是您需要在 while 循环中添加一个 n += 1，例如：

def easy_level():
  n= 0
  while n < 10:
    user_number=int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again=input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
         break

    n += 1

  print('Sorry, no more attempts :(')

长话短说，您真的应该考虑使用 for 循环，下面是一个如何做到这一点的示例：

def easy_level():
  for i in range(10)
    user_number=int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again=input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
         break

  print('Sorry, no more attempts :(')

并且您应该通过删除像这样的重复代码来使您的脚本更清晰：

from random import *

def chooseLevel():
  user_level=input('Type E for easy level and D for difficult level: ')
  if user_level=='e':
    return 10
  else:
    return 5

number = randint(1,100)
for i in range(chooseLevel()):
    user_number = int(input('Guess the number: '))
    if user_number > number:
      print('Too high')
    elif user_number < number:
      print('Too low')
    elif user_number == number:
      print(f'You guessed the number {number}! Congratulations!')
      play_again = input('Would you like to play again? type y for yes or n for no: ')
      if play_again =='y':
        levels()
      else:
        print('Bye')
         break

  print('Sorry, no more attempts :(')

在这里，我删除了您拥有的两个函数，我做了一个循环，使代码更清晰，我还将 levels() 函数名称更改为 chooseLevel()为了更清楚地说明函数的作用，我还在 = 之间添加了空格，这让事情看起来更清晰。

我也是这样使用for循环的for i in range(chooseLevel()) 这意味着如果 chooseLevel() 函数返回一个 5 就好像我写了 for i in range(5) 并且如果 chooseLevel() 函数 returns 一个 10就好像我写了 for i in range(10)

谢谢。

如何在 n 次迭代后停止 while 循环？

How to stop a while loop after n iterations?

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while-loop