I run this:
In [303]: %prun my_function()
384707 function calls (378009 primitive calls) in 83.116 CPU seconds
Ordered by: internal time
ncalls tottime percall cumtime percall filename:lineno(function)
37706 41.693 0.001 41.693 0.001 {max}
20039 36.000 0.002 36.000 0.002 {min}
18835 1.848 0.000 2.208 0.000 helper.py:119(fftfreq)
--snip--
What do each of tottime, percall, cumtime? ncalls is fairly obviously (number of times the function is called). My guess is that tottime is the total time spent in the function excluding time spent within its own function calls; percall is ???; cumtime is total time spent in the function call including time spent within its own function calls (but of course, excluding double counting). The docs are not too helpful; Google search doesn't help either.