That is interesting. It's possible that they have done some optimisations on loops since the last time I measured it, but that was back in Python 2.6 (I think),

That is interesting. It's possible that they have done some optimisations on loops since the last time I measured it, but that was back in Python 2.6 (I think), and map was much faster than a loop (no comprehensions back then), and it was particularly obvious on very high number of input elements. Also, from your description I suspect that the list() call over a generator might introduce extra overhead, rather than map itself...