How to Change the Working Directory in Python

You change the working directory in Python with os.chdir(path), and check where you are with os.getcwd(). After the change, every relative file path is resolved from the new folder:

import os

os.chdir("monthly")
print(os.getcwd())

The folder names below are real ones I created under C:\pyguides, and every script ran on Python 3.12.5 in Command Prompt.

You’ll see the basics, the two errors chdir raises, a temporary change with contextlib.chdir, why relative paths depend on it, and how to work from your script’s own folder.

How to change the working directory with os.chdir()

The current working directory (cwd) is the folder Python treats as “here”. It starts as the folder you ran Python from, not necessarily where your script lives:

import os

print("start: ", os.getcwd())
os.chdir("monthly")                    # relative to where you are now
print("now:   ", os.getcwd())
print("files: ", os.listdir())         # listdir() with no argument uses the cwd

os.chdir("..")                         # back up one level
print("back:  ", os.getcwd())

Output:

start:  C:\pyguides
now:    C:\pyguides\monthly
files:  ['2026-10', 'readme.txt']
back:   C:\pyguides

You can pass a relative path, as here, or an absolute one like r"C:\Reports\2026". A raw string avoids backslash escapes on Windows.

Errors when you change the working directory

os.chdir() raises FileNotFoundError for a folder that doesn’t exist and NotADirectoryError if the path is a file. The cwd stays where it was:

import os

for target in ["montly", os.path.join("monthly", "readme.txt")]:
    try:
        os.chdir(target)
    except FileNotFoundError as err:
        print("FileNotFoundError:", err)
    except NotADirectoryError as err:
        print("NotADirectoryError:", err)

print("still in:", os.getcwd())

Output:

FileNotFoundError: [WinError 2] The system cannot find the file specified: 'montly'
NotADirectoryError: [WinError 267] The directory name is invalid: 'monthly\\readme.txt'
still in: C:\pyguides

To check first, use os.path.isdir(path). There’s more in checking if a directory exists in Python.

Changing directory temporarily with contextlib.chdir

Python 3.11 added contextlib.chdir. It switches folders for the length of a with block and switches back afterward, even if an error happens:

import os
from contextlib import chdir

print("before:", os.getcwd())
with chdir(os.path.join("monthly", "2026-10")):
    print("inside:", os.getcwd())
    with open("sales.csv") as f:          # a short relative path works here
        print("read:  ", f.readline().strip())
print("after: ", os.getcwd())             # restored automatically

Output:

before: C:\pyguides
inside: C:\pyguides\monthly\2026-10
read:   city,total
after:  C:\pyguides

It’s the same pattern as with open() as file. One caution from the docs: the working directory is shared by the whole process, so this isn’t safe in multithreaded code.

Why relative paths depend on the working directory

A bare file name like "sales.csv" is looked up in the cwd. That’s why a script can work in your editor but fail when you run it from another folder:

import os

def read_report():
    with open("sales.csv", encoding="utf-8") as f:
        return f.read().splitlines()[1]

try:
    print(read_report())
except FileNotFoundError as err:
    print("FileNotFoundError:", err.filename, "not in", os.getcwd())

os.chdir(os.path.join("monthly", "2026-10"))
print("after chdir:", read_report())

Output:

FileNotFoundError: sales.csv not in C:\pyguides
after chdir: Austin,1250.50

How do you set the working directory to the script’s folder?

Build the folder from __file__. Then you can either chdir into it or, better, build full paths from it without changing the cwd at all:

import os
from pathlib import Path

here = Path(__file__).resolve().parent
os.chdir(here)                                 # run from anywhere, work from the script's folder
print("cwd matches script folder:", Path.cwd() == here)
print("home folder name exists:", Path.home().exists())

Output:

cwd matches script folder: True
home folder name exists: True

I prefer full paths in bigger programs, since changing the cwd affects every module. os.path.join() and pathlib both help with that, and getting the current directory covers more ways to read it.

os.chdir vs alternatives

Tool	What it does	Use it when
os.getcwd() / Path.cwd()	Shows the current folder	Debugging path problems
os.chdir(path)	Changes it for the rest of the run	Simple scripts
contextlib.chdir(path)	Changes it inside a with block	A few lines need a different folder
Full paths from __file__	No change at all	Libraries and larger apps

More folder and path guides to try next:

• Make a directory in Python
• List files in a directory
• Move a file in Python
• Import from another directory

Frequently asked questions