os.listdir() / os.makedirs() / os.remove()

import os

# Returns a list of file and directory names in the specified directory
os.listdir(path)

# Creates directories recursively
os.makedirs(path, exist_ok=True)

# Creates a single directory (raises an error if the parent does not exist)
os.mkdir(path)

# Deletes a file
os.remove(path)

# Renames or moves a file or directory
os.rename(old_path, new_path)

# Returns the current working directory
os.getcwd()

# Changes the current working directory
os.chdir(path)

os_listdir_basic.py

import os

entries = os.listdir('.')
print(entries)

files = [f for f in os.listdir('.') if os.path.isfile(f)]
print(files)

current = os.getcwd()
print(f'Current directory: {current}')

Running the code produces the following output:

python3 os_listdir_basic.py
['main.py', 'utils.py', 'config.json', 'data']
['main.py', 'utils.py', 'config.json']
Current directory: /home/user/projects

os_listdir_makedirs.py

import os

os.makedirs('output/reports/2025', exist_ok=True)
print('Directory created.')

try:
    os.mkdir('new_folder')
    print('Folder created.')
except FileExistsError:
    print('Already exists.')

with open('temp.txt', 'w') as f:
    f.write('temporary file')

if os.path.exists('temp.txt'):
    os.remove('temp.txt')
    print('File deleted.')

Running the code produces the following output:

python3 os_listdir_makedirs.py
Directory created.
Folder created.
File deleted.

os_listdir_walk.py

import os

with open('old_name.txt', 'w') as f:
    f.write('content')
os.rename('old_name.txt', 'new_name.txt')
print('File renamed.')

for dirpath, dirnames, filenames in os.walk('.'):
    for filename in filenames:
        full_path = os.path.join(dirpath, filename)
        print(full_path)

Running the code produces the following output:

python3 os_listdir_walk.py
File renamed.
./main.py
./utils.py
./config.json
./data/input.csv

Common Mistake 1: Not specifying exist_ok=True with os.makedirs()

Without exist_ok=True, os.makedirs() raises a FileExistsError if the directory already exists. Specifying exist_ok=True allows the script to be run any number of times without errors.

import os

os.makedirs('output/reports')

The same logic can also be written as:

import os

os.makedirs('output/reports', exist_ok=True)

Common Mistake 2: Expecting os.listdir() to traverse subdirectories

os.listdir() returns only the entry names directly inside the specified directory. Subdirectory contents are not included. To traverse directories recursively, os.walk() can be used for file operations.

import os

all_files = os.listdir('.')
print(all_files)

The same logic can also be written as:

import os

all_files = []
for dirpath, dirnames, filenames in os.walk('.'):
    for filename in filenames:
        all_files.append(os.path.join(dirpath, filename))
print(all_files)

os.listdir() returns only the entry names directly inside the specified directory. It does not include the contents of subdirectories. To traverse directories recursively, os.walk() can be used for file operations.

With os.makedirs(), specifying exist_ok=True prevents an error if the directory already exists. This is useful for writing idempotent scripts — ones that produce the same result no matter how many times you run them.

Files deleted with os.remove() are permanently removed and do not go to the trash. Always confirm before deleting, or back up important files before performing file operations.

For path manipulation, see os.path.join() / os.path.exists() / os.path.basename(). For a more modern approach to path handling, see pathlib.Path().