builtin-open (PTH123)

Derived from the flake8-use-pathlib linter.

Fix is sometimes available.

What it does

Checks for uses of the open() builtin.

Why is this bad?

pathlib offers a high-level API for path manipulation. When possible, using Path object methods such as Path.open() can improve readability over the open builtin.

Examples

with open("f1.py", "wb") as fp:
    ...

Use instead:

from pathlib import Path

with Path("f1.py").open("wb") as fp:
    ...

Known issues

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

Fix Safety

This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.

References

• Python documentation: Path.open
• Python documentation: open
• 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