[Python-Dev] turtle.py update for 3.1

[Gregor Lingl]

Hi,

Encouraged by a conversation with Martin at PyCon 2009
I've prepared a version 1.1b of the turtle module and I'd like to
get some advice or assistance to get it into the beta as explained
below. Thus I'd appreciate very much if also the release manager
would take notice of this posting.

python 2.0 had the version 1.0 and for now I'll give a terse
summary of the changes I did:

1. a few bugfixes, with 1 - 5 lines of code changed for each;
    these concern bugs that prevented turtle to run correctly

2. I've added four methods to the class TurtleScreeenBase:
    _onkeypress(fun, key)  (supplementing _onkeyrelease)
    mainloop()  (which is now a Screen-method and a function)
    textinput(title, prompt)
    numinput(title, prompt, default, minval, maxval)
           the latter two remedy the complete lack of input methods
 
    _onkey, an internal method name is changed to _onkeyrelease

3. I've added one method to the class TurtleScreen:
    onkeypress(fun, key=None) 
        implemented in analogy to the already present onkey()
        which got onkeyrelease as an alias.

4. I've changed several portions of the code that affect
   the representation of the turtleshape thus making it
   more compact (by removing some duplicated code) and more
   powerful, i. e. by adding the possibility to apply
   shearings to turtleshapes (in addition to the already present
   scaling and rotating transformations). Thus now the full
   range of (non singular) linear transformations is available.

   New methods in class RawTurtle:
    shearfactor(shear=None)    set or get the shearfactor
    shapetransform(t11, t12, t21, t22)
                    set or get the shape transform directly
    get_shapepoly() return the polygon of the current shape

   I've enhanced the functionality of tiltangle(angle=None)
   to contain also that of settiltangle and I propose to
   declare settiltangle as deprecated.
   
5. I've removed a lot of codelines that were commented out
   during the process of transferring the module from 2.6
   to 3.0

6. I've implemented the bugfix for http://bugs.python.org/issue4117
   according do my proposition there and I strongly
   recommend this change again, as the bug described is very
   annoying, the fix is easy and no one proposed a better
   solution.

7. I've tested the present version 1.1 extensivly. It runs
   all the demo scripts without problems and many others
   too (some of them significantly better than version 1.1).
   I'd like to add two additional scripts to the demo
   directory, one of them using new features so it only runs
   with this new version.

I've *not* touched the issue of the Screen singleton, so that
remains unchanged as it was as a result of Martins patch.

Thus, as a summary, this update does some bugfixes and eliminates
three deficiencies of the module: (1) accept keypress event,
(2) provide user input functions and (3) complement scaling
and rotating of turtleshapes by shearing, thus providing
the full range of linear transforms.

HOW TO PROCEED NOW?

(1) Submit the new version as a single file
(2) submit a unified diff containing all the changes
(3) Divide the changes into several chunks of
    related changes and submit the according diffs separately
    That would pose the problems, that there are lines
    in the code that are affected by several changes,
    e. g. those lines that define __all__
    And also: does the order of applying the patches matter?
    How do I have to account for this?
(4) Some other approach?

I'd appreciate to discuss open issues as needed and I'm
prepared to give more elaborate explanations and rationales
as wanted or as needed.

Docs for the changes are (to a large extent) contained in the
docstrings and I'm going to update the Documentation of the
turtle module (on the basis of theses docstrings) now.

Thanks in advance for your support

Gregor