[Idle-dev] Python Shell - was: RE: IDLE's save-before-run r equirement

[Patrick K. O'Brien]

Thank you, Guido, for bearing with me on this whole issue. I think we are
getting to the heart of the matter. Because I, too, am an instant
gratification person. So let's just talk about the Python Shell
(interactive) capabilities as they exist in the various IDEs. I will attempt
to explain my take on this situation, what bothers me, and what I'd like to
see happen.

The four tools under discussion. IDLE, Boa, PythonWin and VPython all have a
Python Shell capability. But they all vary in their support of keybindings,
coloring, indenting, etc. When someone uses all of these tools and makes use
of each Shell, they have to keep in mind all the variations that exist. This
is counter-productive and takes away from what should be "instant
gratification at all times." I would rather have a common feature set within
all Shells, even if it meant giving up features, rather than have the
variations that exist now. I would like to see the Python Shell exist as
some kind of plug-in or shared code base that all the IDEs could use so that
the Python Shell was uniform in all tools on all platforms. I think this
fits the Python philosophy and would make life a lot easier for beginners as
well as experts. It would also make the Shell available for new,
special-case tools that have been discussed, such as a Python Tutor or
Python Trivial Pursuit game, where the variations would be solely within the
value-add portions and not the fundamental Shell capability (and without
creating yet more forks).

Here are some specific examples of the variations that bother me (Please
don't anyone take offense at these comparisons. I believe they are all
objective, demonstrable differences and not just my opinion, though I am
clearly opinionated. And if I'm wrong about any of this please let me
know.):

PYTHONSTARTUP: IDLE and VPython support it with the -s command line switch.
Boa will have this feature in the next release (because I asked for it).
PythonWin has no support whatsoever for PYTHONSTARTUP to my knowledge.

Home key: Type a line of code at the shell prompt (>>>) and then hit the
Home key. PythonWin puts the cursor in front of your code (very nice). IDLE
and VPython put the cursor in front of the prompt and then beep when you try
to continue typing (yuck). Boa puts the cursor in front of the prompt and
lets you type over the prompt. When you hit enter it truncates the first
four characters from what you typed and tries to execute that (big yuck). I
use this feature a lot in PythonWin when I'm copying previous lines down and
want to get to the beginning of the line to add more code, like assigning to
a variable or some such. When I switch to one of the other tools I have to
do Home, Right, Right, Right, Right - way too many keystrokes.

Command history: IDLE and VPython have Alt-P (previous) and Alt-N (next),
which is very nice. PythonWin has a way to add these bindings, but by
default has Ctrl-Up and Ctrl-Down (just to be different?). I don't know how
to add the PythonWin bindings to IDLE or VPython. Boa has no command
history.

Call tips: PythonWin has the best as far as showing what is in a module.
IDLE/VPython have the best as far as showing function parameters and
docstrings. Boa is way behind.

Win32All: PythonWin is the only tool that can deal with the win extensions,
like dde or com. This is a major pain. There are times when I'd love to use
IDLE but since I'm developing a Windows app that requires DDE I can only use
PythonWin. (And I don't really understand why this is but it definitely
irritates me to no end.)

I'm sure there are other differences, but these are good enough to get my
point across. So I will finish with a question - What, if anything, can be
done about this situation, or am I barking up the wrong tree?

---
Patrick K. O'Brien
Orbtech
"I am, therefore I think."

-----Original Message-----
From: guido@cj20424-a.reston1.va.home.com
[mailto:guido@cj20424-a.reston1.va.home.com]On Behalf Of Guido van Rossum
Sent: Thursday, June 21, 2001 7:41 AM
To: alan.gauld@bt.com
Cc: israel@lith.com; pobrien@orbtech.com; mats@laplaza.org;
idle-dev@python.org; Edu-sig@python.org; tutor@python.org
Subject: Re: [Tutor] Re: [Edu-sig] RE: [Idle-dev] IDLE's save-before-run r
equirement

> > What would switching over to using Scintilla accomplish that
> > sticking with IDLE and continuing it's development wouldn't?
>
> In a word "Reuse". That means one editor to maintain for most
> of the Python IDEs. Add a feature to Scintilla and its pretty
> trivial for all the IDEs to pick up the new feature without
> having to reimplemnent it from scratch. Effort gets concentrated
> on the value add bits rather than the nitty gritty of text editing.

But IDLE has a bunch of requirements that I don't think Scintilla can
provide.  IDLE has really two editing modes: the regular module/file
editor, and the "Python Shell".  IDLE's most redeeming feature, IMO,
is the Python Shell.  Compare editing an interactive session in
PythonWin's console window with IDLE's Python Shell.  IMO again, IDLE
is infinitely better, because it uses the exact same editing features
as the module/file editor, meaning you get proper syntax coloring,
automatic indentation, call tips, magic expansion; and on top of that
you get per-line syntax checking, whole-command editing, and history
recall.  In PythonWin's much more primitive console, it's very easy to
mess up the input or the output or confuse the auto-indenter.

(I'm an instant gratification person, so Python's interactive mode is
very important to me.)

I could be wrong about Scintilla not supporting this, but if it did,
why would PythonWin not use it for *its* console?

--Guido van Rossum (home page: http://www.python.org/~guido/)