He and his kind are in a different reality

I’ve heard this a lot of late, but it’s not clear to me why. Would you be willing to expand on your assertion?

Personally, I’ve written a fair chunk of typescript and asyncio based Python over the year for a project and in general I think Python has done an excellent job of their implementation.

Some things are annoying; for example I’ve a consistent case, which I haven’t pared down to better understand, where by exceptions in a coro are never visible. Not to be confused with the classic case of being notified of the exception when your process shuts down.

OTOH some things are really amazing, for example PYTHONASYNCIODEBUG=1. More so the ability to wrap non async, typically blocking, code in an Executor and it “magically” (via thread pools) work in the event loop has also been a boon for the type of work I’m engaged in.

Waaaaay back, I was really hurt by twisted and to a lesser extent tornado. But the async stuff shipped in 3.9x seems completely comparable to JavaScript imho.

The memory footprint shouldn't be bad, just one page per user.

Weird, none of the issues in my career as a full stack dev ever have been due to a lack of async primitives.

There are much more elegant ways of doing concurrency than Promises and coloured (async vs regular) functions, if that's the issue.

That makes me concerned. Does anyone here know if FastAPI is better? How many concurrent connections could your Express app handle at once?

Agreed. I found Flask after being really annoyed with learning Django. Flask + Heroku is an awesome combo for the hobbyist like myself.

But this works for me:

    @app.errorhandler(ApplicationError)
    def handle(e):
        resp = e.args[0]
        resp.headers["Access-Control-Allow-Origin"] = "..."
        resp.status_code = 500
        return resp

    @app.route("/err")
    def err():
        raise ApplicationError(jsonify({"reason": "test"}))