使用while循环

 num = 1
 while num <= 10:
     print(num)
     num += 1

让用户选择何时推出循环

 print("tell me something\n")
 message = ""
 while message != "quit":
     message = input("message:")
     print(message)

 print("tell me something\n")
 message = ""
 while message != "quit":
     message = input("message:")
     if message != "quit":
         print(message)

退出时不会将quit也打印出来

使用标志判断程序是否处于活动状态，应为可能需要多个变量决定程序是否需要继续执行，此例中极active

 print("tell me something\n")
 active = True
 message = ""
 while active:
     message = input("message:")
     if message == "quit":
         active = False
     else:
         active = True
         print(message)

使用break推出循环

 print("tell me something\n")
 active = True
 message = ""
 while active:
     message = input("message:")
     if message == "quit":
         break
     else:
         active = True
         print(message)

continue语句

当程序执行到continue时，程序判断继续执行

在while语句中在列表之间移动元素

 un = ["A", "B", "C"]
 ed = []
 while un:
     ing = un.pop()
     print(f"ing>ed:{ing}")
     ed.append(ing)

 for ing in ed:
     print(ing)

删除列表中的其特定元素

 pets = ["A", "B", "C"]
 print(pets)

 while 'B' in pets:
     pets.remove('B')
 print(pets)

使用用户输入填充字典

这是一个调查程序，收集调查者的姓名和回答

 responses = {}  
 active = True         设置标志指出程序是否继续执行
 while active:
     name = input("please input the name:")     提示输入调查者的姓名和回答
     response = input("please input the response_you:")
     responses[name] = response
     repeat = input("please choose whether to go Y/N:")    判断是否还有人要参与调查
     if repeat == "N":
         active = False

 print("\n调查结束")
 for name, response in responses.items():
     print(f"{name} : {response}")