Chapter 3: create command-line tool

1. associated with the command line Python language features

1) Using sys.argv get command line arguments

import sys
print(sys.argv)

2). Sys.stdin using standard input and read fileinput

import sys
def get_content():
    return sys.stdin.readlines()
print(get_content())
使用Ctrl+d退出

fileinput is very simple to use, in most cases, we directly call fileinput module input method by reading the contents of the line can be 
used for loop through the contents of the file 
# CAT read_from_fileinput.py 
from  __future__  Import print_function
 Import fileinput 

for Line in fileinput.input ( ):
     Print (Line, End = "  " ) 

# CAT / etc / passwd | Python read_from_fileinput.py

3) Use SystemExit abnormal print an error message

4) Use the library to read the password getpass 

import getpass
user = getpass.getuser()
passwd = getpass.getpass('your password: ')
print(user,passwd)

 

2. Use configparser parsing the configuration file

import configparser
cf = configparser.ConfigParser(allow_no_value=True)
cf.read('/etc/my.cnf')
print(cf.sections())
print(cf.has_section('client'))
print(cf.options('client'))
print(cf.has_option('client','user'))
print(cf.get('client','user'))

 

3. Use argparse parse command line arguments

1) .ArgumentParse parser

2). Mimic the MySQL client's command line arguments

 

4. Use logging logs

Role 1). Log

2) .Python a logging module

3) Configure log format

 

The command line associated with open source projects

1) using the parse command line parameters click

2) Use prompt_toolkit create an interactive command-line tool