os-path-dirname (PTH120)

Derived from the flake8-use-pathlib linter.

What it does

Checks for uses of os.path.dirname.

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.parent can improve readability over the os.path module's counterparts (e.g., os.path.dirname()).

Examples

import os

os.path.dirname(__file__)

Use instead:

from pathlib import Path

Path(__file__).parent

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

• Python documentation: PurePath.parent
• Python documentation: os.path.dirname
• PEP 428 – The pathlib module – object-oriented filesystem paths
• Correspondence between os and pathlib
• Why you should be using pathlib
• No really, pathlib is great