Tangential, but is there a way to annotate an expression as non-nullable? In TS we have `expression!`, but in Python we have to `assert var is not None` after `

Tangential, but is there a way to annotate an expression as non-nullable? In TS we have `expression!`, but in Python we have to `assert var is not None` after `var = fn_that_returns_str_or_none`.