[PYTHON] A quick look at your profile within the django app

I think it's a good habit to take a look at the profile as well as write the test when implementing a bunch of procedures. Optimizing too early isn't good, but just recognizing a small bottleneck before a performance problem becomes apparent gives you the leeway to "tune at any time."

# coding:utf-8

import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings")

import django
django.setup()


if __name__ == "__main__":
    """
    $ cd /path/to/project
    $ python -m project.profile
    """
    import cProfile
    import pstats

    #The function you want to see in the profile
    from app.models import func_to_profile

    prf = cProfile.Profile()
    prf.runcall(func_to_profile)
    pstats.Stats(prf
        ).sort_stats('time'  #Internal time sort in descending order
        ).print_stats(.03)   #Top 3%Show only

The result display looks like this

$ python -m project.profile
         9109096 function calls (8991335 primitive calls) in 8.224 seconds

   Ordered by: internal time
   List reduced from 463 to 14 due to restriction <0.03>

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
   125620    0.723    0.000    0.723    0.000 /path/to/django/utils/dateparse.py:107(<dictcomp>)
    62810    0.631    0.000    0.805    0.000 /path/to/django/db/models/base.py:388(__init__)
   125620    0.435    0.000    1.702    0.000 /path/to/django/utils/dateparse.py:84(parse_datetime)
   265490    0.395    0.000    0.640    0.000 /path/to/django/db/models/fields/related.py:1619(local_related_fields)
      670    0.339    0.001    3.027    0.005 {method 'fetchmany' of 'sqlite3.Cursor' objects}
   125620    0.292    0.000    2.242    0.000 /path/to/django/db/backends/sqlite3/utils.py:6(parse_datetime_with_timezone_support)
   279460    0.291    0.000    0.474    0.000 /path/to/django/db/models/fields/related.py:1633(get_instance_value_for_fields)
   265490    0.205    0.000    1.209    0.000 /path/to/django/db/models/fields/related.py:1627(get_local_related_value)
   549522    0.199    0.000    0.199    0.000 {hasattr}
   127330    0.198    0.000    0.198    0.000 {method 'match' of '_sre.SRE_Pattern' objects}
672800/561660    0.194    0.000    0.423    0.000 {setattr}
   127330    0.175    0.000    0.175    0.000 {method 'groupdict' of '_sre.SRE_Match' objects}
    55570    0.157    0.000    0.263    0.000 /path/to/django/db/models/fields/related.py:615(__set__)
   376960    0.154    0.000    0.254    0.000 /path/to/django/db/models/fields/related.py:1609(related_fields)(app)

Looking at the result, it seems that it is difficult to parse sqlite data to datetime. You can see that it is possible to take measures such as narrowing down the columns to be parsed in case of emergency.