litestats 1.0.0

Convert cprofile/pstats files into sqlite databases.

# 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:

```bash
$ pip install litestats
```


## Usage

```bash
$ # 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:

```sql
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
```