Python教程：跳出多层循环for、while

for跳出多层循环

break_flag = False
for i in range(10):
    print("爷爷层",i)
    for j in range(10):
        print("=爸爸层",j)
        if j == 3:
            break_flag = True
            break
        for k in range(10):
            print("===>孙子层",k )
            if k == 2:
                break_flag = True
                break
        if break_flag:
            break
    if break_flag: #if break_falg == True:
        print("我儿子死了，我也不活了..")
        break
print("keep going....")

while跳出多层循环

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break_flag = False
count = 0
while break_flag == False  :
    print("爷爷层。。。")
    while  break_flag == False:
        print("爸爸层...")
        while  break_flag == False:
            count +=1
            if count >10:
                break_flag = True
            print("炎龙层...")
print("keep going....")

跳出多级菜单

map={
    "华南":{
        "广东":["广州市","佛山市","深圳市","东莞市"],
        "广西":["南宁市","柳州市","桂林市","北海市"],
        "海南":["海口市","三亚市","三沙市","儋州市"]
             },
    "华东":{
        "上海":["黄浦区","卢湾区","徐汇区","长宁区"],
        "安徽":["合肥市","芜湖市","淮南市","马鞍山市"],
        "江苏":["南京市","无锡市","徐州市","常州市"]
            }
}
flag = False
while flag == False:
    print("中国有如下地区：")
    for i in map.keys():
        print(i)
    area = input("请选择一个地区、b或者q：").strip()
    if area == "b":
        break
    if area == "q":
        flag = True
    if len(area) == 0:
        continue
    if area in map.keys():
        while flag == False:
            print("该地区有如下省：")
            for j in (map[area]).keys():
                print(j)
            province = input("请选择一个省、b或者q：").strip()
            if province == "b":
                break
            if province == "q":
                flag = True
            if len(province) == 0:
                continue
            if province in  (map[area]).keys():
                while flag == False:
                    print("该省有如下城市：")
                    for j in map[area][province]:
                        print(j)
                    city = input("请选择b或者q:")
                    if city == "b":
                        break
                    if city == "q":
                        flag = True
                    if len(city) == 0:
                        continue

跳出多层循环简化版

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":{
            "火车战":{
                "携程":{}
            }
        },
        "浦东":{},
    },
    "山东":{},
}
last_layers =  [  menu  ]  #上一层
current_layer = menu  #当前层
while True:
    for key in current_layer:
        print(key)
    choice = input(">>:").strip()
    if len(choice)==0:continue
    if choice in current_layer: #进入下一层
        last_layers.append(current_layer) #当前层添加到列表
        current_layer = current_layer[choice] #北京
    if choice == "b":
        if last_layers:
            current_layer = last_layers[-1] #取到上一层，赋值给current_layer
            last_layers.pop()
    if choice == "q":
        break