Help regarding python run time

[Ian Kelly]

On Wed, May 20, 2015 at 9:48 AM, Irmen de Jong <irmen.NOSPAM at xs4all.nl> wrote:
> Or measure the actual CPU clock cycles taken instead of the wall clock run time.
> Then you should get a fairly constant number, if the program does the same work every
> time you run it.
>
> phobos:~ irmen$ time python test.py
> real    0m3.368s
> user    0m0.214s    <--- cpu time spent in user mode actually doing work
> sys     0m0.053s

And yet:

$ time python3 primes.py

real 0m1.101s
user 0m1.099s
sys 0m0.000s
$ time python3 primes.py

real 0m1.135s
user 0m1.128s
sys 0m0.004s
$ time python3 primes.py

real 0m1.162s
user 0m1.147s
sys 0m0.013s

http://unix.stackexchange.com/questions/162115/why-does-the-user-and-sys-time-vary-on-multiple-executions