OS Module

The python OS module provides functions used for interacting with the operating system and also get related information about it. The OS comes under Python's standard utility modules. This module offers a portable way of using operating system dependent functionality.

The python OS module lets us work with the files and directories.

There are some functions in the OS module which are given below:

os.name

This function provides the name of the operating system module that it imports.

Currently, it registers 'posix', 'nt', 'os2', 'ce', 'java' and 'riscos'.

Example

snippet

import os 
print(os.name)

Output

posix

os.getcwd()

It returns the Current Working Directory(CWD) of the file.

Example

snippet

import os 
print(os.getcwd())

Output

C:\Users\Python\Desktop\ModuleOS

os.error

The functions in this module defines the OS level errors. It raises OSError in case of invalid or inaccessible file names and path etc.

Example

snippet

import os 
try: 
    # If file does not exist, 
    # then it throw an IOError 
    filename = 'Python.txt' 
    f = open(filename, 'rU') 
    text = f.read()  
    f.close() 
  
# The Control jumps directly to here if  
#any lines throws IOError.     
except IOError: 
  
    # print(os.error) will <class 'OSError'> 
    print('Problem reading: ' + filename)

Output

Problem reading: Python.txt

os.popen()

This function opens a file to, or from the command specified and it returns a file object which is connected to a pipe.

Example

snippet

import os 
fd = "python.txt"  

# popen() is similar to open() 
file = open(fd, 'w') 
file.write("This is awesome") 
file.close() 
file = open(fd, 'r') 
text = file.read() 
print(text) 
  
# popen() provides gateway and accesses the file directly 
file = os.popen(fd, 'w') 
file.write("This is awesome") 
# File not closed, shown in next function.

Output

This is awesome

os.close()

This function closes the associated file with descriptor fd.

Example

snippet

import os 
fr = "Python1.txt"
file = open(fr, 'r') 
text = file.read() 
print(text) 
os.close(file)

Output

Traceback (most recent call last): File "main.py", line 3, in file = open(fr, 'r') FileNotFoundError: [Errno 2] No such file or directory: 'Python1.txt'

os.rename

In this function, a file or directory can be renamed by using the function os.rename(). A user can rename the file if it has privilege to change the file.

Example

snippet

import os 
fd = "python.txt"
os.rename(fd,'Python1.txt') 
os.rename(fd,'Python1.txt')

Output

Traceback (most recent call last): File "main.py", line 3, in os.rename(fd,'Python1.txt') FileNotFoundError: [Errno 2] No such file or directory: 'python.txt' -> 'Python1.txt'

os.access()

This function uses real uid/gid to test if the invoking user has access to the path.

Example

snippet

import os 
import sys

path1 = os.access("Python.txt", os.F_OK) 
print("Exist path:", path1) 
  
# Checking access with os.R_OK 
path2 = os.access("Python.txt", os.R_OK) 
print("It access to read the file:", path2) 
  
# Checking access with os.W_OK 
path3 = os.access("Python.txt", os.W_OK) 
print("It access to write the file:", path3) 
  
# Checking access with os.X_OK 
path4 = os.access("Python.txt", os.X_OK) 
print("Check if path can be executed:", path4)

Output

Exist path: False It access to read the file: False It access to write the file: False Check if path can be executed: False