unspecified-encoding (PLW1514)

Derived from the Pylint linter.

Fix is always available.

This rule is unstable and in preview. The --preview flag is required for use.

What it does

Checks for uses of open and related calls without an explicit encoding argument.

Why is this bad?

Using open in text mode without an explicit encoding can lead to non-portable code, with differing behavior across platforms.

Instead, consider using the encoding parameter to enforce a specific encoding. PEP 597 recommends using locale.getpreferredencoding(False) as the default encoding on versions earlier than Python 3.10, and encoding="locale" on Python 3.10 and later.

Example

open("file.txt")

Use instead:

open("file.txt", encoding="utf-8")

References

• Python documentation: open