Thread by @treyhunner

I love Python's pathlib module. 💖🐍🗃

Whenever I need to ask a question about a file path in #Python, I default to using pathlib.

Let's talk about some of my most common uses for pathlib and compare them to their non-pathlib alternatives. 🧵

Assume all the below examples include the "filename" and "path" variables defined like this:

>>> from pathlib import Path
>>> filename = "my_file.txt"
>>> path = Path(filename)

Also assume that we've imported os, glob, and os.path as needed:

>>> import glob, os, os.path

Get an absolute path (from a path that may be relative or may already be absolute).

💾 Old approach:

>>> filename = os.path.abspath(filename)

✨ pathlib approach:

>>> path = path.resolve()

Read entire file contents into a string.

💾 Old approach:

>>> with open(filename) as f:
... contents = f.read()
...

✨ pathlib approach:

>>> contents = path.read_text()

Get just the filename from a path

💾 Old approach:

>>> name = os.path.basename(filename)

✨ pathlib approach:

>>> name = path.name

Get a sibling path in the same directory

💾 Old approach:

>>> filename2 = os.path.join(os.path.dirname(filename), "config.toml")

✨ pathlib approach:

>>> path2 = path.parent / "config.toml"

Change the file extension

💾 Old approach:

>>> os.rename(filename, os.path.splitext(filename)[0] + ".csv")

✨ pathlib approach:

>>> path.rename(path.with_suffix(".csv"))

Check whether given path is a file

💾 Old approach:

>>> if not os.path.isfile(filename):
... print(f"Not a file: {filename}")
...

✨ pathlib approach:

>>> if not path.is_file():
... print(f"Not a file: {filename}")
...

Find all .py files in and below this file's directory:

💾 Old approach:

>>> parent = os.path.dirname(filename)
>>> py_paths = glob.iglob("**/*.py", root_dir=parent, recursive=True)

✨ pathlib approach:

>>> py_paths = path.parent.rglob("*.py")

And keep in mind that Path objects are accept nearly anywhere a string-representing-a-path is accepted.

>>> with open(path) as f:
... for line in f:
... print(line.rstrip())
...

Even utilities like subprocess.run and shutil.move accept Path-like objects.

📺 This pathlib infomercial was brought to you by

• A need to work with file paths in Python
•, My dislike of awkwardly nested function calls
•, An appreciation for using concrete objects instead of just passing strings around everywhere

Follow me for more #Python tips. 🐍🌠

I keep seeing replies about how Path objects need to be converted to strings to actually use them. This was true (& was the reason I didn't like pathlib in Python 3.4), but it's not true anymore.

That's no longer a reason not to use pathlib.

https://twitter.com/treyhunner/status/1527652065492672512