hardcoded-string-charset (FURB156)

Derived from the refurb 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 hardcoded charsets, which are defined in Python string module.

Usage of named charsets from the standard library is more readable and less error-prone.

x = "0123456789"
y in "abcdefghijklmnopqrstuvwxyz"

Use instead

import string

x = string.digits
y in string.ascii_lowercase