[Python-Dev] xturtle.py a replacement for turtle.py(!?) ATTENTION PLEASE! (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Wed Jun 28 23:17:48 CEST 2006

Gregor Lingl wrote:

Sorry Martin, but to me this seems not to be the right way to manage things.

As you explain later, this is precisely the right way; it is unfortunate that it isn't always followed.

(Who reviewed it? This is a newlyadded function - did nobody try it out yet? Incredible!!)

Apparently not. Thanks for pointing that out; Georg (who committed the patch originally) just fixed it in r47151.

This illustrates the main point: Even small changes need careful review. Much more so large changes.

[turtle does not just fill the shape, but the entire boundary polygon]

What a shame!! An immanent bug, persistent for years now!

If the bug had existed for years, somebody could have contributed a patch.

Bugs like the one I detected above (by chance) cannot occur in the code of my xturtle, because I don't have to type the definitions of those frunctions into the script by hand. Instead they are generated automatically from the corresponding methods of RawPen and Pen respectively.

That's all good and well. It still needs to be reviewed.

And aren't 25+ bugfree samplescripts of great variety and broad range in complexity to consider a more reliable proof of at least usability than the procedure you applied?

It's not only about finding bugs. It's also about studying the consistency of the new API, and so on.

As for "reliable proofs": An automatic test suite for turtle.py would be a good thing to have.

A more courageous and less bureaucratic approach to the problem would be appropriate. Perhaps combined with some fantasy.

This bureaucracy has worked fine all the years, and in cases where it was relaxed, we had to regret the changes we accepted more often than not (just like the bug you discovered: the patch should not have been accepted without test cases).

P.S.: If this posting doesn't move points of view, at least it reveals one fixable bug in turtle.py (albeit also one unfixable!)

The approach used in xturtle (i.e. represent circles as polylines) could also be used for turtle.py, no?

Regards, Martin

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