[Idle-dev] The '>>> ' prompt is bad

[Terry Reedy]

On 6/14/2012 12:47 PM, Alan Gauld wrote:
> On 17/01/12 01:00, Terry Reedy wrote:
>> In http://bugs.python.org/issue7676 msg151418
>> I conclude that putting a prompt on the first user entry line of each
>> statement is a mistake that can only be solved by removing it. I see
>> three alternatives. Discussion here or there welcome.
>>
>
> Having a prompt *only* on the first line is bad.
> Not having any prompt would be worse.

Two of my three alternatives are to put the prompt *elsewhere*, either 
above or to left (with secondary prompts) of the user entry area, but in 
any case, cease mixing it with the user entry area in the way it is no

> Doing what the standard interpreter does

The standard interpreter on Windows puts fixed-pixel width prompts (not 
so important, but not completely unimportant either) in a separate 
fixed-width column (critical) to the left that can be omitted when 
copying (also important). That *is* one of my three proposals. So I take 
you comment as a vote for that one.

> would be best (and consistent for users of both). ie:

The question is whether this is possible with tk.

The secondary prompt works best with fixed pitch fonts and the ability 
to copy rectangular blocks. Issue 7676 is about switching from tabs to 4 
spaces for indents. Unicode fonts are variable pitch. With 
variable-pitch font and 4 space indents, ... takes much less space than 
 >>> and consequently the first indent may not look like an indent. 
Indeed, with Lucida Sans Unicode, '...     ' is *shorter* than '>>> ', 
so that the first indent is visually a dedent! This is not acceptible. 
So visually, the result is not at all like the standard interpreter.

So again, the question is whether it is possible to segregate a 
fixed-width read-only column in a tk text box that properly scrolls with 
the main part of the box (and which is omitted from selections). 
Notepad++ does this but perhaps it uses native widgets. (Since it is GPL 
open source, I could check, but have not.) Notepad++ also grays out the 
line-number column, so that there is visually a straight, vertical, text 
margin.

> Where both prompt characters can be user defined for bonus credits...
> Being able to strip the prompts when copy/pasting (like PyCrust does)
> would earn a gold star.

Best would be the possibility to simply not select prompts.

-- 
Terry Jan Reedy