← Back to Python Course | Chapter 12: Standard Library | Lesson 1 of 9

Python os Module

The os module lets your program talk to the computer's files and folders, like a remote control for the file cabinet. You can list, create, and remove things.

In this page:

  1. Getting Working Directory
  2. Creating and Deleting Folders
  3. Listing Directory Contents
  4. Joining and Splitting Paths
  5. Checking File Existence
Syntax
python 
import os

os.getcwd()
os.listdir(path)
os.path.join(part1, part2)

Getting Working Directory

The os module is the main interface between your script and the underlying operating system.

os.getcwd() returns the absolute path of the directory your program was launched from or has since changed into, which is often the reference point for building other relative paths.

Example: Getting Working Directory

python 
import os
print(os.getcwd())

Creating and Deleting Folders

os.mkdir() creates a single new directory and fails if any parent directory in the path doesn't already exist, while os.makedirs() creates the entire chain of intermediate directories needed.

os.rmdir() only removes a directory if it's completely empty, refusing to delete anything that still contains files.

Example: Creating and Deleting Folders

python 
import os

os.makedirs("demo_dir/sub", exist_ok=True)  # creates every intermediate directory needed
os.rmdir("demo_dir/sub")  # only works because the directory is empty
print("Folder created and removed")

Listing Directory Contents

os.listdir(path) returns the names of every file and subdirectory directly inside the given folder, as a plain list of strings with no distinction between the two kinds of entries.

You typically pair it with os.path.isfile() or os.path.isdir() afterward if you need to tell files and folders apart.

Example: Listing Directory Contents

python 
import os
print(os.listdir("."))

Joining and Splitting Paths

Building file paths with plain string concatenation breaks across operating systems because Windows uses backslashes while Unix-like systems use forward slashes.

os.path.join() inserts the correct separator for whatever platform the code is running on, so the same code produces valid paths everywhere.

Example: Joining and Splitting Paths

python 
import os
path = os.path.join("folder", "file.txt")  # inserts the correct separator for the current OS
print(path)

Checking File Existence

os.path.exists() checks whether anything -- file or directory -- exists at a given path, returning False rather than raising an error if it doesn't.

os.path.isfile() and os.path.isdir() narrow that check further, letting you confirm not just that a path exists but which kind of thing it actually is.

Example: Checking File Existence

python 
import os
print(os.path.exists("."))  # True whether it's a file or a directory
print(os.path.isdir("."))  # confirms it's specifically a directory
Related Topics

Python sys Module · Python math Module · Python random Module · Python datetime Module

{# common_mistakes/chapter_summary/browser_support: on Hindi pages the view already swaps in the hi_ translation fields (or blanks these out if untranslated), so this renders correctly for both languages without a lang_code check here. #}
Common Mistakes
  1. Building paths with string concatenation such as "folder" + "/" + "file" instead of os.path.join(), which breaks across operating systems.
  2. Calling os.mkdir() on a folder that already exists, which raises FileExistsError; use os.makedirs(path, exist_ok=True).
  3. Using os.remove() on a directory, which fails; use os.rmdir() or shutil.rmtree().
🔒

Chapter Quiz — Complete all 9 topics to unlock

0/9 topics done

Complete these topics first:

← Previous Lesson Python collections Module Next Lesson → Python sys Module

Login to run this code

C/C++/Java/PHP execution requires a free account. Your code is saved — you'll land right back in the editor after logging in.