On 2014-02-04 16:19, Joao S. O. Bueno wrote:
On 28 January 2014 01:18, Ron Adam email@example.com wrote:
On 01/24/2014 07:36 PM, Andrew Barnert wrote:
> > While we're speculatively overgeneralizing, couldn't all of the > index/find/remove/replace/etc. methods take a negative n to > count from the end, making r variants unnecessary?
Strings already provide rfind and rindex (they're just not part of the general sequence API). Since strings are immutable, there's also no call for an "remove".
I was responding to Serhiy's (probably facetious or devil's advocate) suggestion that we should regularize the API: add rfind and rindex to tuple (and presumably Sequence), and those plus rremove to list (and presumably MutableSequence), and so on.
My point was that if we're going to be that radical, we might as well consider removing methods instead of adding them. Some of the find-like methods already take negative indices; expanding that to all of the index-based methods, and doing the equivalent to the count-based ones, and adding a count or index to those that have neither, would mean all of the "r" variants could go away.
How about a keyword to specify which end to index from? When used, it would disable negative indexing as well. When not used the current behaviour with negative indexing would be the default.
direction=0 # The default with the current (or not specified) # negative indexing allowed. direction=1 # From first. Negative indexing disallowed. direction=-1 # From last. Negative indexing disallowed.
(A shorter key word would be nice, but I can't think of any that is as clear.)
I've just picked the whole thread at once - and I am a little surprised no one suggested what looks obvious to me (or maybe someone did, I went over the e-mails rather quickly):
Why not simply to allow negative indexes to the count argument?
It is pretty much unambiguous, straightforward (hmm..actually, the opposite of that) and Pythonistas are used to think of negative indices as counting from the right. Moreover, the convention could be used for index, remove and even overloaded for split, and other methods as well.
.split, .rsplit and .replace all currently use -1 to indicate no maximum.
Oh, and .index and .rindex don't have a count argument! :-)