I’m a fan of iPython. I use it on the command line instead of the regular
python interpreter. It comes with a bunch of builtin “magic functions”; one of which is
timeit, that allows you to show how long it takes for a Python statement or expression to complete.
Here is an example of timing the creating of a 10,000 x 10,000 two-dimensional list:
$ ipython ... In : %timeit [  * 10000 for _ in range(10000) ] 734 ms ± 5.94 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)
iPython ran this statement 7 times and reported that it took an average of 734 milliseconds to create the list.