[Python-ideas] List assignment - extended slicing inconsistency

[Serhiy Storchaka]

23.02.18 20:50, Chris Angelico пише:
> Ignoring backward compatibility, it ought to be possible to (ab)use a
> stride of zero for this. Calling slice.indices() on something with a
> stride of zero raises ValueError, so there's no ambiguity. But it
> would break code that iterates in a simple and obvious way, and (ugh
> ugh) break it in a very nasty way: an infinite loop. I'm not happy
> with that kind of breakage, even with multiple versions posting a
> warning.
> 
> In the C API, there's PySlice_GetIndices "[y]ou probably do not want
> to use this function" and PySlice_GetIndicesEx, the "[u]sable
> replacement". Much as I dislike adding *yet another* function to do
> basically the same job, I think that might be the less-bad way to do
> this.

Actually PySlice_GetIndicesEx is deprecated too. It is not safe for 
resizeable sequences since it is vulnerable to race condition. The pair 
of PySlice_Unpack() and PySlice_AdjustIndices() replaces it in new code.

So now we have 4 functions for doing the same thing in C, 2 of them are 
deprecated. Do you want to deprecate the other two and add new 
replacements for them?