It's entirely possible he wrote this before itertools existed. Like in the IAQ where he says things like: "Better to stick with x += 1, which was added in Pyt

It's entirely possible he wrote this before itertools existed. Like in the IAQ where he says things like: "Better to stick with x += 1, which was added in Python 2.0. " ( http://norvig.com/python-iaq.html http://norvig.com/python-iaq.html )