Usability of the Python syntax -- field comments

[gvanrossum]

When I was writing my Python schema I noticed that I have to use a rather verbose syntax to add comments to a schema:

    x: Annotated[int, Doc("X-coordinate of the top left corner.")]

Looking at the translated TypeScript schema, this gets turned into the much cleaner

    // Top left corner coordinates
    x: number;

I would like to be able to use native Python in-line comments, like this:

    x: int  # X-coordinate of the top left corner.

I think this could be implemented by scanning the source code instead of, or in addition to, passing the schema data structure.