python acquaintance (a)

Configuration environment variable

• Purpose: decrease in the input path cmd, so that the operation convenient

python suffix: .py

Two execution methods:

• cmd terminal input path: Python interpreter, py file path;
• Entering the python interpreter, real-time input to obtain the results.

Interpreter path and encoded using

#!/usr/bin/env python
# -*- coding:UTF-8 -*-

User and password input operation

n1 = input ( 'Enter a username') 
N2 = INPUT ( 'Enter Password') 
Print (N1) 
Print (N2)

a1 = input ( 'username') 
IF A1 == 'ZX': 
    A2 = INPUT ( 'password') 
    IF A2 == '123': 
        Print ( 'Welcome') 
    the else: 
        Print ( 'error code') 
the else : 
    Print ( 'username error')

variable name

• Only by letters, numbers, underscores  composition dd_2) 55d
• You can not start with a number, 88_ass
• Python keywords can not be used (and, AS, Assert, BREAK, class, Continue, DEF, del, elif ...) class = 123
• Can not be repeated and built something python

Variable naming is an art userid userID  user_id

Conditional statements

• Code block: 4 space indentation / Tab key

1 == 1 IF: 
    Print ( "Success") 
the else: 
    Print ( 'failure')

IF . 1. 1 == :
     IF 2 == 2 :
         Print ( ' success ' )
     the else :
         Print ( ' failure ' )
 the else :
     Print ( ' failure ' )

inp = input ( 'Enter level') 
IF InP == "senior member": 
    Print ( 'beauty') 
elif InP == "Platinum Member": 
    Print ( 'polish') 
elif InP == "Platinum Membership": 
    Print ( 'member') 

Print ( 'begin service')

a = 1
if a < 9:
    pass
else:
    print(a)