How do you use %timeit on a .py file?

Question

%timeit sortThis 
Output: 15.1 ns ± 0.163 ns per loop (mean ± std. dev. of 7 runs, 100000000 loops each)

Tried this but it's not giving me the right output.

sortThis is a .py file with a simple function that sorts a list. I've timed it with a stopwatch and it's way more than what the command is returning.

Thank you for your help.

EDIT: This is for a homework assignment and I must use %timeit in the command line.

You have a `sortThis` variable (most likely from `import sortThis`), and you're timing how long it takes to retrieve the variable. — user2357112, Jul 21 '18 at 00:09
Are you doing this in a bare IPython console, or in a Jupyter notebook, or in Spyder, or somewhere else? — Rory Daulton, Jul 21 '18 at 00:14

Rory Daulton · Answer 1 · 2018-07-21T17:57:27.330

In my IPython console (IPython 6.4.0 with Python 3.6.5, installed under Anaconda 5.2), this works.

%timeit %run sortThis

Be careful of several things. Use the %cd magic command to make sure your current working directory is the one holding the sortThis script. Either that, or include the path to the script in your command. Also, if the script prints anything, you could end up with hundreds or thousands of copies of the printing in your console before %timeit shows its results.

When I had just the command print('Hello, world!') in the sortThis script, I got this result:

1.23 ms ± 5.97 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

I'm pretty sure that the first load of the script caused Python saved the compiled version to a .pyc file and and that file was in my computer's cache. So the stated time averaged all that over many executions, resulting in a small time interval. So don't expect %timeit to time your first execution of the script--just the average over many consecutive executions.

Thank you. It didn't work with just "run" which does work by itself, but not with timeit, giving a syntax error. — Martino, Dec 19 '18 at 13:59

score 1 · Answer 2 · answered Jul 21 '18 at 00:40

Define an entry point for your script, a function into which you move all of the stuff that was at the top-level of the script. If your old script is

import someStuff

def doStuff(y):
    return someStuff.stuff(y)

x = 100   
print(doStuff(x))

Then your new script would be

import someStuff

def doStuff(y):
    return someStuff.stuff(y)

def main():
    x = 100   
    print(doStuff(x))

if __name__ == '__main__':  
    main()

if __name__ == '__main__' makes the script still runnable directly.

Then just do %timeit yourfile.main()

How do you use %timeit on a .py file?

2 Answers2