python 基础（一）

1.branch:

example 1

if else 语句

1 #if else
2 username = "joker"
3 password = "123456"
4 in_user = input("name:")
5 in_passwd = input("password:")
6 if username == in_user and password == in_passwd :
7     print("welcome to login in...")
8 else:
9     print("username or password not correct!")

example 2

if else、if elif、while 语句

 1 #little game for if else elif and while
 2 user = "admin"
 3 psswd = "weak1234"
 4 count = 0
 5 while count < 3:
 6     user_name = input("name:")
 7     pass_wd = input("password:")
 8     if(user == user_name and psswd == pass_wd):
 9         print("oh ,your hacked my account!")
10         break
11     elif count == 2:
12         print("you have tried so many times")
13     else:
14          print("i am a strong admin ,you gays fuck off!")
15     count += 1
16 else:
17     print("you don't have any chance any more ,see you!")

example 3

for 语句 和 range() 函数

 1 #for and range(start,end,steps)
 2 #print the numbers from 1 to 10
 3 for i in range(1,11):
 4     print(i,end=" ")
 5 print()
 6 #print the even numbers
 7 for i in range(0,11,2):
 8     print(i,end=" ")
 9 print()
10 #print the odd numbers
11 for i in range(1,12,2):
12     print(i,end=" ")
13 print()

example 4

不明文显示输入的密码，getpass标准库

1 #getpass
2 import getpass
3 username = input("name:")
4 password_1 = input("password:")
5 password_1 = getpass.getpass("password:")    # in pycharm it doesn't work

2.格式化输出：

打印一个简单的自我介绍情况

example 1

占位符：%s、%d、%f

 1 #格式化输出
 2 name=input("name:")
 3 age=int(input("age:"))
 4 job=input("job:")
 5 salary=float(input("salary:"))
 6 msg1='''-----------name:%s------------
 7 name:%s
 8 age:%d
 9 job:%s
10 salary:%f
11 '''%(name,name,age,job,salary)
12 print（msg1）

example 2

format()函数

 1 #格式化输出
 2 name=input("name:")
 3 age=input("age:")
 4 job=input("job:")
 5 salary=input("salary:")
 6 msg2='''-----------name:{_name}------------
 7 name:{_name1}
 8 age:{_age}
 9 job:{_job}
10 salary:{_salary}
11 '''.format(_name=name,_name1=name,_age=age,_job=job,_salary=salary)
12 print(msg2)