pyupgrade

[cclauss]

https://github.com/asottile/pyupgrade

% ruff check --select=UP --target-version=py38 --statistics # https://docs.astral.sh/ruff/rules/#pyupgrade-up

7	UP009	[*] utf8-encoding-declaration
7	UP025	[*] unicode-kind-prefix
7	UP031	[ ] printf-string-formatting
3	UP034	[*] extraneous-parentheses
2	UP004	[*] useless-object-inheritance
1	UP032	[*] f-string
Found 27 errors.
[*] 20 fixable with the `--fix` option (2 hidden fixes can be enabled with the `--unsafe-fixes` option).

% ruff rule UP009

utf8-encoding-declaration (UP009)

Derived from the pyupgrade linter.

Fix is always available.

What it does

Checks for unnecessary UTF-8 encoding declarations.

Why is this bad?

PEP 3120 makes UTF-8 the default encoding, so a UTF-8 encoding
declaration is unnecessary.

Example

# -*- coding: utf-8 -*-
print("Hello, world!")

Use instead:

print("Hello, world!")