This is not how timeit works, you just measured the time taken by an empty loop, you can look at `python3 -m timeit -h` to get help how to call it. I think a correct invocation would be:

(venv) ➜  ~ python3 -m timeit -s 'from os import scandir' "list(scandir('/usr/local'))"
10000 loops, best of 5: 24.3 usec per loop
(venv) ➜  ~ python3 -m timeit -s 'from os import listdir' "listdir('/usr/local')"
10000 loops, best of 5: 22.2 usec per loop

so it looks like scandir as a small overhead when accumulating all results and not using the extra info it returns.