Write a professional reference script in Python

Q: Linux system commands such as LS, it has dozens of parameters, can take one or more parameters, in no particular order, used to be very professional. But you write the script, generally only a parameter, if the number of multiple, is also a fixed order, then how to use Python to write a more professional communication script it?

Answer: Use the Getopt module that comes with Python.

1 , Syntax:

Import getopt

Getopt.getopt (args,shortopts, longopts=[])

# Examples of functions: Getopt.getopt (sys.argv[1:], ' u:p:p:h ', ["username=", "password=", "port=", "help"])

# output format: [('-P ', ' 123 '), ('-U ', ' root ')] [] #后面中括号包含没有 "-" or "--" parameters

2 , parameter description:

args All parameters of the parameter, generally by sys.argv[1:], that is, all the content of the parameters;

shortopts short format, general parameters such as-u,-p,-h (a "-") is a short format, that is written in the function is "u:p:p:h", there is a colon is a parameter, no colon represents no parameters.

longopts long format, general parameters such as--username,--password,--help and so on (two "-") is the long format, which is written in the function is ["usrname=", ' password= ', "help"], Where--help is not a value, so there is no equal number. The other has an equals sign, which indicates that parameters are required later.

3 , demo effect:

Short format parameters:

[[email protected] scripts]# python getopt_test.py-u yangyun-p 123456-p 2222

Username:yangyun

password:123456

port:2222

Long format parameters: (can also add = number)

[[email protected] scripts]# python getopt_test.py--username yangyun--password 123456--port 2222

Username:yangyun

password:123456

port:2222

Long and short formats are used:

[[email protected] scripts]# python getopt_test.py--username=yangyun-p 123456--port 2222

Username:yangyun

password:123456

port:2222

Only a single parameter is passed, and the other is the default value:

[[email protected] scripts]# python getopt_test.py-p 123456

Username:root

password:123456

Port:22

# This is the default value for port and user, and the default value is specified in the function .

4 ,python example of a reference script:

# cat  getopt_test.py

#!/usr/bin/python#by yangyun 2015-1-11 import getopt import sys# Importing Getopt,sys Modules   #定义帮助函数def  help ():        print  "usage error!"         sys.exit ()   #输出用户名def  username (username):         print  ' username: ',username  #输出密码def  password (password):         if not password:                 help ()          else:                 print  ' Password: ',password  #输出端口def  port (port):         print  ' port: ',port  #获取传参内容, short format is-u,-p,-p,-h, where-H does not need to pass value. #长格式为--username,--Password,--port,--help, long format--help does not need to pass value. Opts,args=getopT.getopt (sys.argv[1:], ' u:p:p:h ', ["username=", "password=", "port=", "help"])   #print  opts, '      '  ,args# sets the default value variable, and the default value is used when no parameters are passed. Username_value= "root" port_value= ' password_value= '      #密码不使用默认值, so the definition is empty.   #循环参数列表, the output format is: [('-P ', ' 123 '),  ('-U ',  ' root ')]     [] for opt , Value in opts:        if opt in ("-U", "--username" ):                 username_ value=value                # If there is a pass, the value is re-assigned.         if opt in ("-P", "--password"):                 password_value=value         if opt in ("-P", "--port"):                port_value=value         if opt in ("-H", "--help"):                 help ()   #执行输出用户名, password, port function, if there is no value for the variable, the default value is used. Username (username_value) password (password_value) port (port_value)

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Write a professional reference script in Python