Running a benchmark on my system comparing your generator expression version versus their generator function shows that they perform within a small margin of ea

Running a benchmark on my system comparing your generator expression version versus their generator function shows that they perform within a small margin of each other. Yours was marginally (< 1%) faster. (not a real proper benchmark, there's quite a bit running on this computer right now but it still has a lot of free cores so should be close to the same result from a proper benchmark)