python系统学习：第三周之简单的三级菜单

# 三级目录
info = {
    # 一级
    ‘ShanXi‘: {
        # 二级
        ‘JieXiu‘: {
            # 三级
            ‘XiaoSongQv‘: [‘Burn here!‘],
            ‘SanSchool‘: [‘Study here‘]
        }
    },
    ‘BeiJing‘: {
        ‘ChaoYang‘: {
            ‘XianNinghou‘: [‘Live here!‘]
        },
        ‘BeiYuan‘: {
            ‘TieJian‘: [‘Work Here!‘]
        }
    }
}
# 三级目录的跳转
# 定义标志
flag = False
while not flag:
    for name1 in info:
        print(name1)
    # 选择1
    choice = input(‘>>where?‘)
    # 判断是否存在
    if choice in info:
        # 判断成功打印第二层
        while not flag:
            for name2 in info[choice]:
                print(name2)
            # 选择
            choice2 = input(‘>>where?‘)
            # 判断是否存在
            if choice2 in info[choice]:
                # 判断成功打印第三层
                while not flag:
                    for name3 in info[choice][choice2]:
                        print(name3)
                    choice3 = input(‘>>where?‘)
                    if choice3 in info[choice][choice2]:
                        for name4 in info[choice][choice2][choice3]:
                            print(name4)
                        choice4 = input(‘最后一层，b返回,q退出！‘)
                        if choice4 == ‘b‘:
                            pass  # 占位符  我什么都不做
                        elif choice4 == ‘q‘:
                            flag = True
                    elif choice3 == ‘b‘:
                        break
                    elif choice3 == ‘q‘:
                        flag = True
            elif choice2 == ‘b‘:
                break
            elif choice2 == ‘q‘:
                flag = True
    # 输入B返回
    elif choice == ‘b‘:
        pass
    # 输入q退出
    elif choice == ‘q‘:
        flag = True

  或许你认为这个写法比较弱智，但是学习代码都是从麻烦到简单，学会了最原始的写法，能更好的了解运行机制，等后面学了函数等，就变得简单了。

python系统学习：第三周之简单的三级菜单

原文：https://www.cnblogs.com/niushichong/p/10009133.html