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@parallel(10) def f(n): return len(str(factorial(10^6)))
%time list(f([1..10]))
[(((9,), {}), 5565709), (((4,), {}), 5565709), (((8,), {}), 5565709), (((3,), {}), 5565709), (((7,), {}), 5565709), (((5,), {}), 5565709), (((1,), {}), 5565709), (((6,), {}), 5565709), (((10,), {}), 5565709), (((2,), {}), 5565709)] CPU time: 0.06 s, Wall time: 31.69 s
%time len(str(factorial(10^6)))
5565709 CPU time: 1.70 s, Wall time: 1.71 s