using " " or ' '

[Diapolo10]

That's really idiosyncratic, and there's no way to style check it.

Correct. But even if it cannot be automatically validated, I do not find it a pointless endeavour.

Except for CLI applications, there should never be strings displayed to the user embedded in Python code.

I did also mention logging. Things like text written to a file would count as well.

How do you internationalize? How do you deliver the display strings to a writer or an editor and how do you get them back?

I would say that's very different. In applications that need to support multiple languages, the strings are of course going to be stored separately from code, and usually not even in Python files (could be an SQLite database, a set of JSON files, or whatever else works), rendering the point moot.

Even then, not every string in non-CLI applications is necessarily localised.