More to the point, does Python 3 have operators that transform sequential operations into operations that are both concurrent and parallelizable, and, in the case of iteration, provide control of parallelism parameters and whether results are constrained to be in-order or not.

To which the answer is “not only does Python not have them, but with the GIL CPython couldn't do much with them even if the language had them.”

Is that a bit like Go's `go` keyword?

edit: that is, as far as I can tell, after a quick Google, it's not too different from Python's Thread object.

The `start` statement prefix operator is a bit like Go's `go` keyword.

(In that when I translate Go into Raku, I usually replace `go` with `start`.)

    my Channel \input .= new;
    my Channel \output .= new;

    start for input -> \message { output.send(message) }

    start for output -> \message { say message }

    input.send(5);

But what he was really talking about is something more like the following.

    sub foo () {
      sleep 10;
      42
    }

    #                     ___
    #                    V   V
    my $delayed-result = start foo();

    say 'Hello World'; # Hello World

    say $delayed-result.status; # Planned

    say await $delayed-result; # 42

It is, python Threads are system threads.

Yes, async/await. https://docs.python.org/3/library/asyncio-task.html#awaitabl...