There's no reason that `count('', 'a')` for `'', 'a', 'aa', ...` or `count((), (1,))` for `(), (1,), (1, 1), ...` shouldn't work.

count(a, b) should be equivalent to accumulate(chain((a,), repeat(b)))

The docs don't strongly suggest that it won't work (it says *start* is a number, but the "roughly equivalent to" generator would work for str/tuple/etc)

At one moment, I had a need for 

    itertools.count(datetime.date.today(), datetime.timedelta(days=1))

Of course, it was no problem to write it myself, but still, it would be incredibly neat if it simply worked.

Thanks for the suggestion but I'm going to decline.

* The need for this is very low.  

* It's easy to roll your own.

* The code for `count('', 'a')` and `count((), (1,))` isn't intelligible.

* Without special casing, the code for `count('', 'a')` and `count((), (1,))` is highly inefficient.  We advise people not to use the 's = s + t' pattern in a loop for sequences because it leads to quadratic behavior.