5-1 条件测试:编写一系列条件测试;将每个测试以及你对其结果的预测和实际结果都打印出来。
name = 'Li Mei' print("Is name=='Li Mei'?I predict True.") print(name=='Li Mei') print("Is name=='Li Lei'?I predict False.") print(name=='Li Lei')
5-6 人生的不同阶段:设置变量age的值,再编写一个if-elif-else结构,根据age的值判断处于人生的哪个阶段。
age = 3 if age < 2: print("He's a baby.") elif 2<=age and age<4: print("He is a toddler") elif 4<=age and age<13: print("He is a child") elif 13<=age and age<20: print("He is a teenager") elif 20<=age and age<65: print("He is an adult") elif 65<=age: print("He is an old man")
5-8 以特殊方式跟管理员打招呼:创建一个至少包含5个用户名的列表,且其中一个用户名为‘admin’。想象你要编写代码,在每位用户登录网站后都打印一条消息,遍历用户名列表,并向每位用户打印一条问候消息。
usernames = ['admin','Eric','Li Lei'] for username in usernames: if username == 'admin': print("Hello admin,would you like to see a status report?") else: print("Hello "+username+", thank you for logging in again.")
5-9 处理没有用户的情况。在为完成练习5-8编写的程序中,添加一条if语句,检查用户名列表是否为空。
usernames = [] if len(usernames)==0: print("We need to find some users!") else: for username in usernames: if username == 'admin': print("Hello admin,would you like to see a status report?") else: print("Hello "+username+", thank you for logging in again.")