The author seems to misunderstand one part of The Zen of Python: | Simple is better than complex. by saying: > Our code is more complex (O(n2) instead of O(n

The author seems to misunderstand one part of The Zen of Python: | Simple is better than complex. by saying: > Our code is more complex (O(n2) instead of O(n)), less beautiful, and less readable The Zen is not about computation complexity! It's about complexity of the source code. The code in question is: color_counts = dict((c, colors.count(c)) for c in set(colors)) And while I agree that this is inefficient and shouldn't be used in a library, I find this to be very readable and would always prefer that code if I know that I'm dealing only with small lists. It translates neatly to a natural-language description of the problem: Give me a dictionary that maps each distinct color to the number of times it occurs in the list. So I don't think this violates the guide "Simple is better than complex". Rather, it is a good example where it makes sense to introduce additional complexity to improve the performance of an often-used helper function.