python-三级菜单

第一种方法：

# _Author:huang
# date: 2017/11/29

menu = {
    '河南': {
        '郑州': {
            '金水区': {
                '东风路': {},
                '北三环': {},
                '明基路': {}
            },
        },
        '南阳': {
            '淅川县': {},
            '西峡县': {},
            '方程': {},
        },
    },
    '江苏': {
        '南京': {
            '鼓楼': {},
            '栖霞区': {},
            '下关区': {}
        },
        '苏州': {
            '城区': {},
            '苏州园林': {}
        }
    },
    '北京': {
        '昌平区': {
            'sohu': {},
            'sogo': {}
        },
        '昭阳区': {
            '360': {},
            'google': {}
        }
    }
}

current_layer = menu

parent_layers = []

while True:
    for key in current_layer:
        print(key)
    choice = input(">>>:").strip()
    if len(choice) == 0:
        continue
    if choice in current_layer:
        parent_layers.append(current_layer)
        current_layer = current_layer[choice]

    elif choice == 'b':
        if parent_layers:
            current_layer = parent_layers.pop()
    else:
        print("无此地名")




第二种方法：

# _Author:huang
# date: 2017/11/28

menu = {
    '北京': {
        '朝阳': {
            '国贸': {
                'CICC': {},
                'HP': {},
                '渣打一行': {}
            }
        },
        '望京': {
            '陌陌': {},
            '奔驰': {},
            '360': {}
        },
        '三里屯': {
            '优衣库': {},
            'apple': {}
        },
        '昌平': {
            '天通苑': {
                '链家': {},
                '我爱我家': {}
            },
            '回龙观': {},
        },
        '海淀': {
            '五道口': {
                '谷歌': {},
                '网易': {},
                'sohu': {},
                'sogo': {},
                '快手': {},
            },
            '中关村': {
                'youku': {},
                'Iqiyi': {},
                "汽车之家": {},
                "新东方": {},
                'QQ': {}
            }
        }
    },
    '上海':  {
        '浦东': {
            '陆家嘴': {
                'CICC': {},
                '高盛': {},
                '摩根': {}
            },
            '外滩': {},
        },
        '闵行': {},
        '静安': {}
    },

    '山东': {
        '济南': {},
        '青岛': {},
        '德州': {
            '乐陵': {
                '丁坞镇': {},
                '城区': {}
            },
            '平原县': {}
        }
    }
}
back_flag = False
exit_flag = False
while not back_flag and not exit_flag:
    for key in menu:
        print(key)      #  打印第一层代码
    choice = input(">>:").strip()
    if choice == 'b':
        back_flag = True
    if choice == 'q':
        exit_flag = True
    if choice in menu:   #  判断是否在第一层
        while not back_flag and not exit_flag:        #让程序停在第二层
            for key2 in menu[choice]:
                print(key2)     #  打印第二层
            choice2 = input("2>>:").strip()
            if choice2 == 'b':
                back_flag = True
            if choice2 == 'q':
                exit_flag = True
            if choice2 in menu[choice]:
                for key3 in menu[choice][choice2]:
                    print(key3)
                choice3 = input("3>>:").strip()
                if choice3 == 'b':
                    back_flag = True
                if choice3 == 'q':
                    exit_flag = True
                if choice3 in menu[choice][choice2]:
                    while not back_flag and not exit_flag:
                        for key4 in menu[choice][choice2][choice3]:
                            print(key4)
                        choice4 = input("4>>:").strip()
                        print("last lever")
                        if choice4 == 'b':
                            back_flag = True
                        if choice4 == 'q':
                            exit_flag = True
                else:
                    back_flag = False

            else:
                    back_flag = False

    else:
                    back_flag = False