Python之双色球选购和三级菜单问题

1：双色球选购 # 1 双色球（假设一共八个球，6个红球，球号1-32、2个蓝球，球号1-16） # 2 确保用户不能重复选择，不能超出范围 # 3 用户输入有误时有相应的错误提示 # 4 最后展示用户选择的双色球的号码

select_red_ball = [] while True:     n = int(input('请输入你要选择的红色球(1-32)：'))     if 0 < n < 33:         if n not in select_red_ball:             select_red_ball.append(n)         else:             print('number %d is already exist in red ball list' % n)     else:         print('only can select n between 1-32')     if len(select_red_ball) == 6:         break select_red_ball.sort() select_blue_ball = [] while True:     n = int(input('请输入你要选择的蓝色球(1-32)：'))     if 0 < n < 17:         if n not in select_blue_ball:             select_blue_ball.append(n)         else:             print('number %d is already exist in blue ball list' % n)     else:         print('only can select n between 1-16')     if len(select_blue_ball) == 2:         break select_blue_ball.sort() print('red ball %d' % select_red_ball) print('blue ball %d' % select_blue_ball)

2 ：三级菜单

• 数据结构： menu = { '北京':{ '海淀':{ '五道口':{ 'soho':{}, '网易':{}, 'google':{} }, '中关村':{ '爱奇艺':{}, '汽车之家':{}, 'youku':{}, }, '上地':{ '百度':{}, }, }, '昌平':{ '沙河':{ '老男孩':{}, '北航':{}, }, '天通苑':{}, '回龙观':{}, }, '朝阳':{}, '东城':{}, }, '上海':{ '闵行':{ "人民广场":{ '炸鸡店':{} } }, '闸北':{ '火车站':{ '携程':{} } }, '浦东':{}, }, '山东':{}, } 需求： 可依次选择进入各子菜单 可从任意一层往回退到上一层 可从任意一层退出程序 所需新知识点：列表、字典

代码一：

 exit_flag = False while not exit_flag:     for i in menu:         print(i)     choice1 = input("选择进入1>>:")     if choice1 in menu:         while not exit_flag:             for i2 in menu[choice1]:                 print("\t", i2)             choice2 = input("选择进入2>>:")             if choice2 in menu[choice1]:                 while not exit_flag:                     for i3 in menu[choice1][choice2]:                         print("\t\t", i3)                     choice3 = input("选择进入3>>:")                     if choice3 in menu[choice1][choice2]:                         for i4 in menu[choice1][choice2][choice3]:                             print("\t\t", i4)                         choice4 = input("最后一层，按b返回>>:")                         if choice4 == "b":                             pass                         elif choice4 == "q":                             exit_flag = True                     if choice3 == "b":                         break                     elif choice3 == "q":                         exit_flag = True             if choice2 == "b":                 break             elif choice2 == "q":                 exit_flag = True

代码二：（优化版本，代码缩减为15行）

current_layer = menu parent_layer = []  # 将父级key值放入到列表中 flags = False  # 设置标志位 while not flags:     for key in current_layer:         print(key)     choose = input("请选择，输入b返回上一级菜单，输入q退出菜单:").strip()  # 去除空格     if choose in current_layer:         parent_layer.append(current_layer)  # 将当前的状态放入列表中         current_layer = current_layer[choose]     elif choose == 'b':         if parent_layer:             current_layer = parent_layer.pop()     elif choose == 'q':         flags = True     else:         print('输入有误，请重新输入')