How to design a class that will listen on stdin?

[Dan Sommers]

On Saturday, May 23, 2020, at 07:24 -0400, zljubisic at gmail.com wrote:

> I have to talk to outer system by stdin/stdout.
> Each line that comes to stdin should be processed and its result returned back to stdout. Logging should go to stderr.
> 
> How to design a class that will listed to stdin and call required methods in order to process the data?

I wouldn't put it into a class, but the core of it looks something like
this:

    for line in sys.stdin:
        result = process(line)
        print(result)
        if some_condition():
            break

The details may be different, and there's likely more error handling in
production code, but that's the general idea.