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。
