Any developer can care about performance. And should never be mocked for achieving above 200% performance compared to an alternative implementation... Let alone 400% performance compared to the alternatives.

If that 400% performance improvement was achieved by sacrificing code readability, on a project that has deliberately chosen to prioritize readability over performance, then yes they should be mocked. Or at least told not to do it.

It's not an implementation detail, the order is guaranteed by the spec.

> by the spec

by the implementation you mean.

See: http://stackoverflow.com/questions/1094961/is-there-a-python...

As mentioned by others, the documentation for zip explicitly mentions this as a Python idiom: http://docs.python.org/2/library/functions.html#zip