Issue 7460: extended slicing not sufficiently covered in docs (original) (raw)

Issue7460

Created on 2009-12-08 17:20 by donlorenzo, last changed 2022-04-11 14:56 by admin.

Messages (3)
msg96141 - (view)	Author: Lorenz Quack (donlorenzo) *	Date: 2009-12-08 17:20
I find the documentation regarding extended slicing to be lacking. To be honest I couldn't find any documentation about it. The only - and quite good - source of information I found was [1]. Maybe I didn't search enough. If so I would appreciate a link to the relevant section. In fact I didn't really know about extended slicing (except for the start, stop, step notation) until I implemented a C extension and got a TypeError in Python 3 because I was only supporting simple slicing. And this is despite the fact that I don't consider myself a python n00b. As I am still learning about this protocol at the time of writing. I might have some things backwards and I don't feel qualified to improve the docs myself. Instead I would like to point out where I would have expected some information about this topic: To begin improvement a hint around "PySequence_GetSlice" that this is a more or less deprecated API and "tp_as_mapping->mp_subscript" should be used instead would be useful. In addition "PyObject_GetItem/tp_as_mapping->mp_subscript" could say that a slice object is passed when extended slicing is used. sincerely yours //Lorenz PS: I marked this Python 3.x even though the documentation of 2.x lacks as well because I only got the TypeError in 3.x whereas in 2.x everything works fine with simple slicing. [1] http://mail.python.org/pipermail/python-3000/2007-August/009851.html
msg100501 - (view)	Author: Terry J. Reedy (terry.reedy) *	Date: 2010-03-05 21:46
This may be duplicative of #1446619, but I have not looked at that enough. I agree that revision is needed and will try to develop patch suggestions.
msg100503 - (view)	Author: Lorenz Quack (donlorenzo) *	Date: 2010-03-05 22:10
When I wrote this bug report I was mainly thinking about the C-API documentation which doesn't mention extended slicing at all. Since the C-API isn't mentioned in the other bug I don't think it's a duplicate but they could maybe be merged if you see any advantage in that. And thanks for looking into it.