Given "abcdefabcdefabcdef", what is the last result of "abc"? x.rindex("abc") will tell you.
Given [1, 2, 3, 4, 5, 1, 2, 3, 4, 5] where is the last result of 3? reversed(x).index(3) will tell you (or x[::-1]). Notice how with lists you can easily reverse them and still get at the value since you are searching per index. But with strings, you searching by a subslice that can be greater than 1 in which case you can't use a similar approach. On Mon, Apr 22, 2019 at 11:47 PM 林自均 <johnl...@gmail.com> wrote: > Hi all, > > I found that there are str.index() and str.rindex(), but there is only > list.index() and no list.rindex(). So I filed the issue > https://bugs.python.org/issue36639 to provide list.rindex(). However, the > issue was rejected and closed with the comment: > > > There were known, strong use cases for str.rindex(). The list.rindex() > method was intentionally omitted. AFAICT no compelling use cases have > arisen, so we should continue to leave it out. In general, we don't grow > the core APIs unnecessarily. > > However, I am not sure what the known, strong use cases for str.rindex() > are. Why doesn't the strong use cases apply on list.rindex()? Could anyone > give me some examples? Thanks. > > Best, > John Lin > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ >
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