Using IPython's %%time magic within a script to measure CPU time

Question

I work with Jupyter/IPython quite a lot and am used to including %%time magic command in front of each cell to get a hint of the amount of CPU and wall clock time spent.

Is there a simple way to obtain the same measurements from within a script?

More specifically, I'd like to have something like that:

 results = measure_times(something_possibly_parallel)
 print results.wall_clock, results.cpu_user, results.cpu_total

Answer 1

You can implement the desired measure_times() utility as a python context manager. Then the usage will be as below:

with measure_times("block name"):
    your code here

A sample implementation measuring only wall time follows:

$ cat measure_times.py 
import timeit

class measure_times:
    def __init__(self, blockname):
        self.blockname = blockname

    def __enter__(self):
        self.starttime = timeit.default_timer()

    def __exit__(self, exc_type, exc_value, traceback):
        t = timeit.default_timer() - self.starttime
        print('--- Time measurement report: {}: {}s'.format(self.blockname, t))


with measure_times("Integer sum"):
    s = 0
    for i in range(1000000):
        s += i
    print(s)

with measure_times("Floating point sum"):
    s = 0
    for i in range(1000000):
        s += i
    print(s)

$ python measure_times.py 
499999500000
--- Time measurement report: Integer sum: 0.0683062076569s
499999500000
--- Time measurement report: Floating point sum: 0.066034078598s