I would prefer something like `{"name": contains("k")}`, where contains("k") returns an object with a custom __eq__ that compares equal to any string (or iterable) that contains "k". Then you can just filter by equality.

I recently started using this pattern for pytest equality assertions, as pytest helpfully produces a detailed diff on mismatch. It's not perfect, as pytest doesn't always produce a correct diff with this pattern, but it's better than some alternatives.