Python 101: Interactively learn how to program with Python 3/

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Profiling Your Code with cProfile

Profiling Your Code with cProfile

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Profiling code with cProfile is really quite easy. All you need to do is import the module and call its run function. Let’s look at a simple example:

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import hashlib
import cProfile
cProfile.run("hashlib.md5(b'abcdefghijkl').digest()")
#     4 function calls in 0.000 CPU seconds
#   Ordered by: standard name
#   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
#        1    0.000    0.000    0.000    0.000 <string>:1(<module>)
#        1    0.000    0.000    0.000    0.000 {_hashlib.openssl_md5}
#        1    0.000    0.000    0.000    0.000 {method 'digest' of '_hashlib.HASH' objects}
#        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}

Here we import the hashlib module and use cProfile to profile the creation of an MD5 hash. The first line shows that there were 4 function calls. The next line tells us how the results are ordered. According to the documentation, standard name refers to the far right column. There are a number of columns here.

  • ncalls is the number of calls made.
  • tottime is a total of the time spent in the given function.
  • percall refers to the quotient of tottime divided by ncalls
  • cumtime
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