Python教程 跳出多層迴圈for while

for跳出多層迴圈

break_flag = false

for i in range(10):
print("爺爺層",i)
for j in range(10):
print("=爸爸層",j)
if j == 3:
break_flag = true
break
for k in range(10):
print("===>孫子層",k )
if k == 2:
break_flag = true
break
if break_flag:
break
if break_flag: #if break_falg == true:
print("我兒子死了，我也不活了..")
break
print("keep going....")

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break_flag = false
count = 0
while break_flag == false  :
print("爺爺層。。。")
while  break_flag == false:
print("爸爸層...")
while  break_flag == false:
count +=1
if count >10:
break_flag = true
print("炎龍層...")
print("keep going....")

map=,

"華東":
}flag = false
while flag == false:
print("中國有如下地區：")
for i in map.keys():
print(i)
area = input("請選擇乙個地區、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("該地區有如下省：")
for j in (map[area]).keys():
print(j)
province = input("請選擇乙個省、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("該省有如下城市：")
for j in map[area][province]:
print(j)
city = input("請選擇b或者q:")
if city == "b":
break
if city == "q":
flag = true
if len(city) == 0:
continue

menu = ,

'網易':{},
'google':{}
},'中關村':,
'汽車之家':{},
'youku':{},
},'上地':,
},'昌平':,
'北航':{},
},'天通苑':{},
'回龍觀':{},
},'朝陽':{},
'東城':{},
},'上海':}},
'閘北':}},
'浦東':{},
},'山東':{},
}last_layers =  [  menu  ]  #上一層
current_layer = menu  #當前層
while true:
for key in current_layer:
print(key)
choice = input(">>:").strip()
if len(choice)==0:continue
if choice in current_layer: #進入下一層
current_layer = current_layer[choice] #北京
if choice == "b":
if last_layers:
current_layer = last_layers[-1] #取到上一層，賦值給current_layer
last_layers.pop()
if choice == 'q':
break

flag跳出多層迴圈

有時候我們需要從第三層的for迴圈直接跳出第二層的while迴圈,進入第一層迴圈,只用break就做不到了,這時候我們可以用flag.1 用法1 定義標識為ture,然後while flag,比如驗證登入資訊,驗證成功直接改變標識狀態為false,直接跳到第一層while迴圈 不執行else裡的 如...

跳出多層迴圈for while

break flag false for i in range 10 print 爺爺層 i for j in range 10 print 爸爸層 j if j 3 break flag true break for k in range 10 print 孫子層 k if k 2 break f...

如何指定跳出多層迴圈

public class outloopwithlabel 方法二 boolean，break組合 通過boolean型條件變數和break的組合，由內層迴圈在跳出 break 前改變條件變數，外層迴圈檢測條件變數改變時終止外層迴圈。public class outloopwithbooleanbr...