argmax

[Ben Cartwright]

David Isaac wrote:
> 2. Is this a good argmax (as long as I know the iterable is finite)?
> def argmax(iterable): return max(izip( iterable, count() ))[1]

Other than the subtle difference that Peter Otten pointed out, that's a
good method.

However if the iterable is a list, it's cleaner (and more efficient) to
use seq.index(max(seq)).  That way you won't be creating and comparing
all those tuples.

  def argmax(it):
      try:
          it.index
      except AttributeError:
          it = list(it)
          # Or if it would too expensive to convert it to list:
          #return -max((v, -i) for i, v in enumerate(it))[1]
      return it.index(max(it))

--Ben