[Tutor] Understanding cProfile output

[ranveer raghuwanshi]

Thanks for the input everyone.

@Dave, I basically implemented the sieve of eratosthenes to fiind the
number of prime numbers in a given range. So, yes I am looking for
suggestions to speed it up.

On Fri, Sep 21, 2012 at 2:16 AM, Dave Angel <d at davea.name> wrote:

> On 09/20/2012 03:56 PM, Steven D'Aprano wrote:
> > On 21/09/12 04:58, ranveer raghuwanshi wrote:
> >> Hi,
> >>
> >> I am trying to understand the output of cProfile when run against my
> >> python
> >> code. The code is:
> > [...]
> >> What the above code does is it counts the number of prime numbers
> >> less than
> >> 1,00,000.
> >>
> >> Now when I profile this code using *python -m cProfile -s time
> >> countPrime.py.
> > <SNIP>
> >
> > #result9592
> >          90414 function calls in 16.705 seconds
> >
> >    Ordered by: internal time
> >
> >    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
> >         1   16.374   16.374   16.705   16.705 countPrime.py:1(<module>)
> >     90407    0.320    0.000    0.320    0.000 {method 'append' of
> > 'list' objects}
> >         2    0.011    0.005    0.011    0.005 {range}
> >         1    0.000    0.000    0.000    0.000 {math.sqrt}
> >         1    0.000    0.000    0.000    0.000 {math.floor}
> >         1    0.000    0.000    0.000    0.000 {len}
> >         1    0.000    0.000    0.000    0.000 {method 'disable' of
> > '_lsprof.Profiler' objects}
> >
> > <SNIP>
> >
> >
> >> Now what I
> >> don't understand is what it means by *tottime=16.374 for function
> >> countPrime.py:1(<module>). *I understand fine that it took around
> >> *0.320s
> >> for method append.*
> >>
> >> So, is 16.374 the total time my scripts takes but according to
> >> profiler the
> >> total time is 16.705.
> >
> I don't know the Python profiler, but I've worked with many others over
> the years (and even written one).  It looks like it follows very
> reasonable conventions in its output.
>
> tottime is the total time spent in that function, including the
> functions it calls.  cumtime is the cumulative time spent in that
> function, after deducting for any functions it may have called.  So in
> approximate numbers, 16.705 = 16.374 + .320 + .011
>
> Both columns are very useful, as is the ncalls column.  However, the net
> result is you didn't learn very much about the efficiency of your
> algorithm.
>
> Are you looking for suggestions for speeding it up?  Or suggestions for
> getting more interesting results from profiling?
>
>
>
> --
>
> DaveA
>
>


-- 
Ranveer Raghuwanshi
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