Litestats

Profiling in Python has always been easy, however, analyzing the profiler's output not so much. After the profile has been created you can use Python's pstats module but it feels quite clumsy and not really empowering.

Enter litestats! Litestats is a simple command line tool that takes the output of the Python profiler and transforms the data into a sqlite3 database. You can now easily analyze the profiler output using sqlite on the command line, the sqlitebrowser for a graphical interface or use the data base as the foundation of your very own tooling around the analysis.

How does it work?

Litestats reads the dump of the profiler and creates a normalized data base with tree tables:

• functions: contains each function (callers and callees) with filename, line number and function name
• stats contains the statistics (primitive/total calls, total/cumulative time) for all functions
• calls a caller-callee mapping

While this provides an exact representation of the dump, those tables would be cumbersome to use. So litestats additionally creates three views resembling pstats print_stats, print_callers and print_callees functionality:

• pstats
• callers
• callees

Install

Litestats has no requirements other than Python itself:

$ pip install litestats

Usage

$ # run the profiler and dump the output
$ python3 -m cProfile -o example.prof example.py
$ # convert dump to sqlite3 db
$ litestats example.prof
$ # example.prof.sqlite created

You can now use the sqlite3 data base to investigate the profiler dump:

sqlite> select *
   ...> from pstats
   ...> order by cumtime desc
   ...> limit 20;

ncalls      tottime     ttpercall             cumtime     ctpercall   filename:lineno(function)
----------  ----------  --------------------  ----------  ----------  ------------------------------------
18/1        0.000161    8.94444444444444e-06  0.067797    0.067797    ~:0(<built-in method builtins.exec>)
1           1.0e-06     1.0e-06               0.067755    0.067755    <string>:1(<module>)
1           4.0e-06     4.0e-06               0.067754    0.067754    /usr/lib/python3.7/runpy.py:195(run_
1           6.0e-06     6.0e-06               0.066135    0.066135    /usr/lib/python3.7/runpy.py:62(_run_
1           1.1e-05     1.1e-05               0.066113    0.066113    /home/venthur/Documents/projects/lit
1           6.6e-05     6.6e-05               0.055152    0.055152    /home/venthur/Documents/projects/lit
1           4.1e-05     4.1e-05               0.0549      0.0549      /home/venthur/Documents/projects/lit
1           0.050196    0.050196              0.050196    0.050196    ~:0(<method 'executescript' of 'sqli
20/3        8.9e-05     4.45e-06              0.011064    0.003688    <frozen importlib._bootstrap>:978(_f
20/3        4.8e-05     2.4e-06               0.011005    0.00366833  <frozen importlib._bootstrap>:948(_f
20/3        7.5e-05     3.75e-06              0.01083     0.00361     <frozen importlib._bootstrap>:663(_l
15/3        3.5e-05     2.33333333333333e-06  0.01073     0.00357666  <frozen importlib._bootstrap_externa
29/5        2.5e-05     8.62068965517241e-07  0.010215    0.002043    <frozen importlib._bootstrap>:211(_c
3           6.0e-06     2.0e-06               0.010087    0.00336233  ~:0(<built-in method builtins.__impo
28/6        9.0e-06     3.21428571428571e-07  0.008977    0.00149616  <frozen importlib._bootstrap>:1009(_
1           9.0e-06     9.0e-06               0.00841     0.00841     /home/venthur/Documents/projects/lit
16          0.000138    8.625e-06             0.004802    0.00030012  <frozen importlib._bootstrap_externa
1           4.5e-05     4.5e-05               0.004143    0.004143    /usr/lib/python3.7/logging/__init__.
1           0.004038    0.004038              0.004038    0.004038    ~:0(<method 'commit' of 'sqlite3.Con
13          3.3e-05     2.53846153846154e-06  0.002368    0.00018215  <frozen importlib._bootstrap_externa