游戏规则：
游戏有两个山洞，每个山洞有一条龙，友善的龙会把宝物都给你，饥饿的龙会吃掉你，玩家选择进入哪个山洞。

import random
import time

def displayIntro():
    print('''You are in a land full of dragons. In front of you,
you see two caves. In one cave, the dragon is friendly
and will share his treasure with you. The other dragon
is greedy and hungry, and will eat you on sight.''')
    print()

def chooseCave():
    cave = ''
    while cave != '1' and cave != '2':
        print('Which cave will you go into? (1 or 2)')
        cave = input()

    return cave

def checkCave(chosenCave):
    print('You approach the cave...')
    time.sleep(2)
    print('It is dark and spooky...')
    time.sleep(2)
    print('A large dragon jumps out in front of you! He opens his jaws and...')
    print()
    time.sleep(2)

    friendlyCave = random.randint(1, 2)

    if chosenCave == str(friendlyCave):
         print('Gives you his treasure!')
    else:
         print('Gobbles you down in one bite!')

playAgain = 'yes'
while playAgain == 'yes' or playAgain == 'y':
    displayIntro()


    caveNumber = chooseCave()

    checkCave(caveNumber)

    print('Do you want to play again? (yes or no)')
    playAgain = input()

运行结果如下：

1.PNG

一定注意缩进和空格问题。