Python list.index() from end of the list

问题

In python, if I have a list say [2,1,1,3,5], then is it possible to get

[2,1,1,3,5].index(1) as 2 i.e first match starting from the higher end instead of the lower?

回答1:

Can't say I've ever needed to do this, but you could always hack it with:

lst = [2,1,1]
reverseindex = len(lst)-1 - lst[::-1].index(1)

Note that if you had a STRING, you could do:

string = "21135"
reverseindex = string.rindex(1)
# reverseindex == 2

But lists don't have this function.

回答2:

If you don't care about list order being preserved, you could always use lst.reverse() before lst.index(1).

Documentation is on the official site

来源：https://stackoverflow.com/questions/22793248/python-list-index-from-end-of-the-list