Suppose itr_1 is an iterator. Now consider itr_2 = map(lambda x: x, itr_1) itr_3 = itr_1
We now have itr_1, itr_2 and itr_3. There are all, effectively, the same iterator (unless we do an 'x is y' comparision). I conclude that this suggestion amounts to have a __len__ for ANY iterator, and not just a map. In other words, this suggestion has broader scope and consequences than were presented in the original post. -- Jonathan _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/