Consider this a wish list. I know I'm unlikely to get any of these in time for for my birthday, but still I felt the need to toss it out and see what happens.
Lately, I've slinging around a lot of lists, and there are some simple things I'd like to do that just aren't there. s.count(x[, cmp[, key]]) - return number of i‘s for which s[i] == x. 'cmp' specifies a custom comparison function of two arguments, as in '.sort'. 'key' specifies a custom key extraction function of one argument. s.index(x[, i[, j[, cmp[, key]]]]) - return smallest k such that s[k] == x and i <= k < j. 'cmp' and 'key' are as above. s.rindex(x[, i[, j[, cmp[, key]]]]) - return largest k such that s[k] == x and i <= k < j. 'cmp' and 'key' are as above. There are two overlapping proposals here. One is to add the .rindex method, which strings already have. The other is to extend the optional arguments of .sort to all other methods that test for item equality. One last thing, the Python 2.6.2 spec says .count and .index only apply to mutable sequence types. I see no reason why they (and .rindex) couldn't also apply to immutable sequences (tuples, in particular). -- http://mail.python.org/mailman/listinfo/python-list