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os-path-splitext (PTH122)

Derived from the flake8-use-pathlib linter.

What it does

Checks for uses of os.path.splitext.

Why is this bad?

pathlib offers a high-level API for path manipulation, as compared to the lower-level API offered by os.path. When possible, using Path object methods such as Path.suffix and Path.stem can improve readability over the os.path module's counterparts (e.g., os.path.splitext()).

os.path.splitext() specifically returns a tuple of the file root and extension (e.g., given splitext('/foo/bar.py'), os.path.splitext() returns ("foo/bar", ".py"). These outputs can be reconstructed through a combination of Path.suffix (".py"), Path.stem ("bar"), and Path.parent ("foo").

Examples

import os

(root, ext) = os.path.splitext("foo/bar.py")

Use instead:

from pathlib import Path

path = Path("foo/bar.py")
root = path.parent / path.stem
ext = path.suffix

Known issues

While using pathlib can improve the readability and type safety of your code, it can be less performant than the lower-level alternatives that work directly with strings, especially on older versions of Python.

References