[Python-Dev] xturtle.py - a replacement for turtle.py

[Gregor Lingl]

xturtle.py, extended turtle graphics
is a new Tkinter based turtle graphics module for Python

xturtle.py (Version 0.91) can be found at:

http://sourceforge.net/tracker/?group_id=5470&atid=305470
(Request ID 1513695, and 1513699 for the docs)

and at

http://ada.rg16.asn-wien.ac.at/~python/xturtle
together with a set of example scripts and a demoViewer

xturtle was first announced at edu-sig and is reported to 
work properly on all major platforms (Mac, Linux and
Windows) I propose to use it as a replacement for turtle.py

It was suggested to me to discuss it on this list.  So I'll try that.

For now I'll give only two introductory statements and then wait for a response, hoping that a fruitful 
discussion will evolve.

(I) xturtle.py is a reimplementation of turtle.py, retaining its merits and is backward compatible to turtle.py. Enhancements over turtle.py are:


# Better animation of the turtle movements, especially of turning the 
turtle. So the turtles can more easily be used as a visual feedback 
instrument by the (beginning) programmer.
# Different turtle shapes, gif-images as turtle shapes, user defined and 
user controllable turtle shapes, among them compound (multicolored) shapes.
# Fine control over turtle movement and screen updates via |delay()|, 
and enhanced |tracer()| and |speed()|, |update()| methods.
# Aliases for the most commonly used commands, like |fd| for |forward| 
etc., following the early Logo traditions. This reduces the boring work 
of typing long sequences of commands, which often occur in a natural way 
when kids try to program fancy pictures on their first encounter with 
turtle graphcis (still not knowing loops).
# Some simple commands/methods for creating event driven programs 
(mouse-, key-, timer-events). Especially useful for programming simple 
games.
# A scrollable Canvas class. The scrollable Canvas can be extended 
interactively as needed while playing around with the turtle(s) (e. g. 
to follow some escaped turtle). # Commands for controlling background 
color or background image.

(II) Motives: My goal was to provide utmost easy access to a 
sufficiently rich graphics toolkit. I consider this of crucial 
importance for students and teachers who, e. g., have to decide which 
language to use for introductory programming courses. Moreover I 
consider turtle graphics as an excellent tool to visualize programming 
concept. So I already used the current turtle.py as a central tool in 
the first edition of my book "Python für Kids", despite of its apparent 
deficiencies.

Now I propose an alternative: xturtle.py. You will best understand my 
intentions by having a look at the 25+ demo scripts using the 
accompanying demoViewer, which are provided with turtle.zip at the above 
mentioned website. (I do not propose to include these into the standard 
distribution. Perhaps they could go into some special edudistro as Kirby 
Urner suggested lately)

I would appreciate it very much if xturtle.py could go into Python2.5. 
I'm ready to do the amendments, which may emerge as necessary from the 
dicussion here.

Regards,
Gregor Lingl