We've seen how powerful list comprehensions and generator expressions can be. And they are, don't get me wrong, but the feeling that I have when I deal with them is that their complexity grows exponentially. The more you try to do within a single comprehension or a generator expression, the harder it becomes to read, understand, and therefore maintain or change.
If you check the Zen of Python again, there are a few lines that I think are worth keeping in mind when dealing with optimized code:
>>> import this...Explicit is better than implicit.Simple is better than complex....Readability counts....If the implementation is hard to explain, it's a bad idea....
Comprehensions and generator expressions ...
