[Feature request] Indentation for ternary statements

[tylerlaprade]

Ternary statements that are broken across multiple lines are indented at the same level as the parent line, making them very hard to read, especially if surrounded by additional logic. Prettier handles the equivalent case in JS/TS by adding an indentation level to the ternaries. This would likely need to be behind a flag for ease of migration from Black, but ideally this would be the only behavior if that constraint didn't exist.

Ruff

Prettier

[JelleZijlstra]

How would you expect the Python code to be formatted? Since Python ternaries are written out in a different order than JS ternaries, it's difficult to apply the Prettier format directly.

[tylerlaprade]

That's a good point, I hadn't considered that difference. I think a single additional indent in front of if and else would make the most sense.

[MichaReiser]

I like the idea and I want to improve the conditional formatting because the current formatting can be hard to read. That's why Black's now parenthesizes long conditionals but I would prefer to find a more readable style without adding extra parentheses (see psf/black#4123)

[vanakema]

I'm with @tylerlaprade on indenting the if and else. It's simple and it makes it way more readable.

Here's an example
Current Ruff formatting

        foo = Foo(
            bar_id=bar.id,
            baz_id=f'{baz.name}_{bar_numer}_{idx}'
            if bar_number
            else f'{baz.name}_{idx}',
            zap=zap,
        )

Desired ruff formatting (which ruff format does not allow)

        foo = Foo(
            bar_id=bar.id,
            baz_id=f'{baz.name}_{bar_numer}_{idx}'
                if bar_number
                else f'{baz.name}_{idx}',
            zap=zap,
        )

This makes it easier to glean while skimming code that it is a ternary and not part of the arg list