Python -- built in Library OS

Preface

This time python2.9.7 Version to demonstrate . os finger Operating System Abbreviation , It means operating system .os The module provides a very rich way to deal with files and directories , In short, it's python The programming module of the operating system , Can handle files and directories . Usually we do it by hand . Here's the thing to notice os Different methods of modules are for different operating systems ： such as Windows,macos,linux There are some methods with slightly different usage .

os Use

First of all to import Import . Here are some useful built-in functions ：
help function ： You can view the help document of the corresponding module ;
dir function ： Show all the properties and methods of this module .

  Here is a code demonstration !!!

# This library is built-in , You can import references directly 
import os # Import os library 
# help(os) # After execution , see os Library very detailed help documentation . You can see very detailed documentation , Such as ： Method 、 name 、 Sub modules, etc 
print(dir(os)) # Print out the corresponding properties and methods 

Print dir

 os Common methods

Here is a list of os Module common methods , Mainly 3 In terms of .

1. os Operating system related

Through it, you can get the name of the system 、 Environment variables and so on .

  Code ：

'''os Operating system related '''
# Get system name 
print(os.name)
# Get system environment variable information 
print(os.environ) # Dictionary format , All information 
# Get the environment variable information of the specified name 
print(os.getenv('PATH')) # Get path information of system environment variables 
# Execute system instructions 
os.system('pwd') # Windows yes GBK code , Chinese can be garbled , This command will report an error 

2. os Operation directory related

Can pass os The module manages a catalog file , For example, add a new directory 、 Delete 、 Modify the directory, etc .

  Code up ~~

import os
'''os Catalog related '''
# Get the current directory 
print(os.getcwd())
# Toggle directory 
os.chdir('..')
print(os.getcwd())
# List all files in the current directory 
print(os.listdir())
# Create an empty directory 
os.mkdir('demo01')
# Recursive create 
os.makedirs('a/b/c')
# Delete empty directory , Non empty directory cannot be deleted .
os.rmdir('demo01')
# Duplicate a directory 
os.rename('demo01','hello')
# Delete file 
os.remove('world.txt')

3. os Operation path related

The path of the operating system , obtain 、 Division 、 The path of the combined file .