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os-listdir (PTH208)

Added in 0.10.0 · Related issues · View source

Derived from the flake8-use-pathlib linter.

What it does

Checks for uses of os.listdir.

Why is this bad?

pathlib offers a high-level API for path manipulation, as compared to the lower-level API offered by os. When possible, using pathlib's Path.iterdir() can improve readability over os.listdir().

Example

p = "."
for d in os.listdir(p):
    ...

if os.listdir(p):
    ...

if "file" in os.listdir(p):
    ...

Use instead:

p = Path(".")
for d in p.iterdir():
    ...

if any(p.iterdir()):
    ...

if (p / "file").exists():
    ...

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