Mkdir -p functionality in Python

Creating Directories: The Pythonic Way

The cool kids use pathlib

With Python 3.5 came pathlib, letting us use filesystem paths as objects:

from pathlib import Path

# Hello, new neighborhood!
new_path = Path("/new/neighborhood")
new_path.mkdir(parents=True, exist_ok=True) 
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Just like a mkdir -p, this handles missing parents and existing directories!

When Python was a toddler (older than 3.2)

Before Python 3.2, there was no exist_ok. So, we had to check if the directory exists and then make it:

# When we had to walk uphill both ways
if not os.path.exists(directory):
    os.makedirs(directory) 
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Beware! In a multithreaded world, a race condition might occur - always try, catch!

Knock-knock, do I have permission?

Folders are like houses - need the right permissions! Always set the correct mode when making directories:

# Making a directory that's accessible by all, no secret stuff here
os.makedirs('path/to/create', mode=0o770, exist_ok=True) # permission set to rwxrwx--- 
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System calls? More like system stalls

Replacing multiple system calls with Python functionality? Cleaner code, better performance, and safer systems! So, stick with os.makedirs or pathlib.Path.mkdir.

Handling exceptions: because life happens

Work with files, work with exceptions! Always be ready for surprises and use proactive error handling:

try:
    os.makedirs('/some/path')
except OSError as e:
    if e.errno != errno.EEXIST:  
        raise  # Oops, I did it again... Raised an exception, I mean!
    # Handle existing directory warnings 
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Not every path is a directory

Use os.path.isdir() to make sure a path is indeed a directory. Alternatively, os.path.exists() to check for file:

# Fact-checking: Is it really a directory?
if os.path.isdir('/some/path'): 
    print("Yep, it's a directory!")  # Not FAKE news!
else:
    os.makedirs('/some/path')  # If not, we MAKE it!
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Durable Python scripts

Sometimes (rarely though), simple is better, and a single system call might just do the trick:

import subprocess
 
# Sometimes, you gotta do the manual labor
subprocess.run(['mkdir', '-p', 'new/directory'])
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However, the safer choice is to stick with built-in Python functions.