Why is there no platform independent way of clearing a terminal?

[Jonathan Hartley]

On Jul 28, 4:45 pm, Jonathan Hartley <tart... at tartley.com> wrote:
> On Jul 28, 8:08 am, Ulrich Eckhardt <eckha... at satorlaser.com> wrote:
>
>
>
> > Daniel Fetchinson wrote:
> > > After getting the technicalities out of the way, maybe I should have
> > > asked:
>
> > > Is it only me or others would find a platform independent python API
> > > to clear the terminal useful?
>
> > There are two kinds of programs:
> > 1. Those that process input to output. If one of those suddenly started by
> > clearing my screen, I'd just dump it. Also, if output is redirected to a
> > file or piped into another program, that is basically useless or even
> > hurting, since you then end up with control sequences in the file.
>
> > 2. Those that provide a text-based interactive UI. Those typically not only
> > clear the screen, but also control its whole layout and content, so there
> > you don't only need ways to clear the screen but also to position the
> > cursor or draw boxes etc. In that case you need a full "curses" library.
>
> > Summary: No, I don't see the need for such an API.
>
> > Cheers!
>
> > Uli
>
> > --
> > Sator Laser GmbH
> > Geschäftsführer: Thorsten Föcking, Amtsgericht Hamburg HR B62 932
>
> Hey,
>
> Your point seems good and I don't mean to contradict, but out of
> interest, what do you think about an example like the following:
>
> I want to write a quick script which, notices whenever I save my
> source code, and re-runs the unit tests, displaying the output. I
> think I'd like it to clear the terminal before each re-run of the
> tests, so that it's immediately obvious what is output from the
> current run, as opposed to previous runs. Then I can keep my editor
> focussed, but leave that running in a terminal and trust it to simply
> display the current output from my tests.
>
> I did dash off a quick and dirty version of this once which did a
> system 'clear' or 'cls' depending on the platform, but to my dismay I
> found that on Windows this caused focus to jump briefly to the
> terminal every time it ran 'clear' (!), making it extremely annoying
> in use. So I wished there had been a simple cross-platform way to
> clear the terminal. (this, and printing colored text, was my initial
> use case for starting 'colorama')
>
> Is this a silly desire of mine, or simply an uncommon edge case that
> therefore isn't really significant?
>
> Best regards,
>
>   Jonathan


Oh, plus, while we're on this subject:

Am I right that curses in Python stdlib doesn't work on Windows, and
there is currently no simple way to fix this?

Also, is it crazy to imagine that if colorama was pushed through to
completion (ie. to support a majority of the relevant ANSI codes) then
Python's stdlib curses module, unmodified, would suddenly just work on
Windows? (after a call to 'colorama.init()')

I presume these ideas are oversimplifications or just plain wrong. If
anyone would care to correct my misunderstandings, I'd be very
grateful.