1 prompt = "If you tell us who you are, we can pe rsonalize the messages you see."
 2 prompt += "\nWhat is your firstname: "
 3 active = True#控制循环
 4 while active:
 5     name = input(prompt)
 6     if name == ‘quit‘:#控制循环
 7     active = False
 8     #可替换为break，结束循环
 9     #换为continue 则成了死循环
10     else :
11         print("Hello!" + name + "!")
12 
13     print(‘4‘)#测试是否跳出循环

1 unconfirmed_users =[‘alice‘, ‘brain‘, ‘cand‘, ‘ace‘,]
2 confirmed_users =[]
3 while unconfirmed_users:
4     current_user = unconfirmed_users.pop()#弹出并记录
5     print("Verifying user: " + current_user.title())
6     confirmed_users.append(current_user)#添加到新列表中
7     print("\nThe following users have been confirmed: ")
8     for confirmed_user in confirmed_users:#显示已认证用户
9         print(confirmed_user.title())

1 while ‘alice‘ in unconfirmed_users#只要unconfirmed_users列表中存在alice这个元素就一直循环
2     unconfirmed_users.remove(‘alice‘)#删除unconfirmed_users列表中的alice元素

 1 names = {}
 2 while 1:
 3     name = input("What‘s your name : ")
 4     if name == ‘no‘:#强迫输入哈哈哈。
 5         continue
 6     day = input("How old are you: ")
 7     if day == ‘no‘:
 8         continue
 9 #以上俩if可采取if-elif
10     # if name == no:
11         # continue
12     # elif day == no:
13         # continue
14     names[name] = day#自动添加键值对
15     #alien_0[‘x_position‘] = 0 为字典添加键值对
16     #alien_0[‘x_position‘] =25 修改字典中的值
17     repeat = input("Would you like to let an other person respond?(yes/no)")
18     if repeat == ‘no‘:
19         break
20 for a, b in names.items():#打印键值对
21     print(a.title() + b)