Master Python’s os Module: Essential File & Directory Operations

import os

os.mkdir(name)

– creates a new directory named

name

.

os.path.exists(name)

– checks whether a file or directory exists.

os.path.isdir(name)

– returns

True

if the specified path is a directory, otherwise

False

.

os.mknod(name)

– creates an empty file.

os.path.isfile(name)

– returns

True

if the path points to a regular file.

os.rmdir(name)

– removes an empty directory.

os.remove(name)

– deletes a file.

os.getcwd()

– returns the current working directory (equivalent to the Unix

pwd

command).

os.path.abspath(file|dir)

– obtains the absolute path of a file or directory.

os.path.basename(name)

– extracts the final component (file or folder name) from a path.

os.path.dirname(name)

– returns the directory portion of a path.

os.path.splitext

– splits a filename into name and extension.

os.path.split

– separates a path into directory and filename.

os.path.join(path, name)

– joins directory and filename into a single path.

os.chdir(dir)

– changes the current working directory.

os.listdir(dir)

– lists all files and sub‑directories in the specified directory.

os.path.getsize(file|dir)

– returns the size of a file in bytes; for a directory it returns

0

.

os.stat(name)

– retrieves file status information (permissions, timestamps, etc.).

os.system(command)

– executes a system command.

os.rename(old, new)

– renames a file or directory.

os.getuid()

– returns the current process’s user ID.

os.getgid()

– returns the current process’s group ID.

os.environ['VAR_NAME'] = 'value'

– sets an environment variable.

os.environ['VAR_NAME']

– retrieves the value of an environment variable.

os.getenv('VAR_NAME')

– another way to get an environment variable’s value.

os.walk(top, topdown=True, onerror=None, followlinks=False)

– generates the file‑system tree by walking the directory hierarchy either top‑down or bottom‑up.

top – the root directory from which the walk starts; each iteration yields a 3‑tuple

(dirpath, dirnames, filenames)

.

topdown – if

True

(default) the walk proceeds from the top down; if

False

it proceeds from the bottom up.

onerror – a callable that handles errors; it can either log the error and continue or raise an exception to abort the walk.

followlinks – if

True

, symbolic links to directories are traversed.