Day1 - Python基础1 Python介绍、基本语法、流程控制习题集

1、打印Hello World!

 print("Hello World!")

或

 name="你好，世界!"
 print(name)

2、声明变量:打印name1和name2的值

 name1 = "jayson"
 name2 = name1
 print("My name is",name1,name2)
 name1 = "jack"
 print(name1,name2)

3、用户登录：输入用户名和密码

 _username = 'jayson'
 _password = 'abc123'
 username = input("username:")
 password = input("password:")
 if _username == username and _password == password:
     print("Welcome user {name} login!".format(name=username))
 else:
     print("Invalid username or password!")

4、for循环练习一：循环10次

 for i in range(10):
     print("loop",i)
 #i是临时变量
 #range[reɪndʒ] n.范围。
 #range()函数的用法：range(10)表示从0到10，不包含10
 #loop[lu:p] n.环，回路，圈

for循环格式：

for iterating_var in sequence:

  statements(s)

iterating_var:迭代变量（ iterating [ɪtə'reɪtɪŋ] 迭代），sequence: [ˈsi:kwəns] n.序列,statements:[s'teɪtmənts] n.声明

5、for循环练习二：每隔一个就打印一个

 for i in range(0,10,2):#0表示从0开始，2代表每隔1个就跳1个
     print("loop",i)

6、for循环练习三：嵌套循环

 for i in range(10):
     print('***',i)
     for j in range(10):
         print(j)

上面程序外层循环每执行一次，内层循环就执行10次。

 for i in range(10):
     print('***',i)
     for j in range(10):
         print(j)
         if(j > 5):
             break

上面程序当j > 5时，中止本次循环，开始下一次循环。

7、while循环：打印0到1000的整数

 count = 0
 while True:
     print("count:",count)
     count = count + 1 #count +=1
     if count == 1000:
         break

while语句格式：while 判断条件:
                     执行语句......
执行语句可以是单个语句或语句块。判断条件可以是任何表达式，任何非零、或非空（null）的值均为true。当判断条件假false时，循环结束。

8、用户交互程序：输入name,age,job,salary并打印出来

 name = input("name:")
 age = int(input("age:"))
 job = input("job:")
 salary = input("aalary:")
 #1方法一
 info = '''
 ------ info of %s  ------
 Name:%s
 Age:%d
 Job:%s
 Salary:%s
 ''' %(name,name,age,job,salary)
 print(info)

%s表示格式化一个对象为字符，%d表示格式化一个对象为整数。

 name = input("name:")
 age = int(input("age:"))
 job = input("job:")
 salary = input("aalary:")
 #1方法二
 info = '''
 ------ info of {_name}  ------
 Name:{_name}
 Age:{_age}
 Job:{_job}
 Salary:{_salary}
 '''.format(_name=name,
            _age=age,
            _job=job,
            _salary=salary)
 print(info)

 name = input("name:")
 age = int(input("age:"))
 job = input("job:")
 salary = input("aalary:")
 #1方法三
 info = '''
 ------ info of {0}  ------
 Name:{0}
 Age:{1}
 Job:{2}
 Salary:{3}
 '''.format(name,age,job,salary)
 print(info)

PS：打印某个变量的数据类型：

 print(type(age))

 print(type(str(age)))

9、猜年龄：猜三次不中时，程序退出

 #方法一、用for循环
 jayson = 35
 for i in range(3):
     guess_age = int(input("guess age:")) #input输入的内容默认是字符串类型
     if guess_age == jayson:
         print("yes,you got it.")
         break #表示结束整个循环
     elif guess_age > jayson:
         print("think smaller.")
     else:
         print("think bigger.")
 else:#这里的else表示上面的代码正常走完了才会执行
     print("you have tried too many times,exit!")

 #方法二：
 jayson = 35
 count = 0
 while count < 3:
     guess_age = int(input("guess age:"))
     if guess_age == jayson:
         print("yes,you got it.")
         break
     elif guess_age > jayson:
         print("think smaller.")
     else:
         print("think bigger.")
     count +=1
 else:
     print("you have tried too many times,exit")

10、猜年龄：当输入超过3次时询问是否继续？

 jason = 35
 count = 0
 while count < 3:
     guess_age = int(input("guess age:"))
     if guess_age == jason:
         print("yes,you got it.")
         break
     elif guess_age > jason:
         print("think smaller.")
     else:
         print("think bigger.")
     count +=1
     if count == 3:
         continue_confirm = input("do you want to keep guessing?")
         if continue_confirm !="n":
             count = 0

单词记忆：continue  [kənˈtɪnju:] v.继续；break [breɪk] v.跳出循环；confirm  [kənˈfɜ:m] vt.确认，确定，证实。