cpython/Doc
Daniel Olshansky 01602ae403 bpo-37958: Adding get_profile_dict to pstats (GH-15495)
pstats is really useful or profiling and printing the output of the execution of some block of code, but I've found on multiple occasions when I'd like to access this output directly in an easily usable dictionary on which I can further analyze or manipulate.

The proposal is to add a function called get_profile_dict inside of pstats that'll automatically return this data the data in an easily accessible dict.

The output of the following script:

```
import cProfile, pstats
import pprint
from pstats import func_std_string, f8

def fib(n):
    if n == 0:
        return 0
    if n == 1:
        return 1
    return fib(n-1) + fib(n-2)

pr = cProfile.Profile()
pr.enable()
fib(5)
pr.create_stats()

ps = pstats.Stats(pr).sort_stats('tottime', 'cumtime')

def get_profile_dict(self, keys_filter=None):
    """
        Returns a dict where the key is a function name and the value is a dict
        with the following keys:
            - ncalls
            - tottime
            - percall_tottime
            - cumtime
            - percall_cumtime
            - file_name
            - line_number

        keys_filter can be optionally set to limit the key-value pairs in the
        retrieved dict.
    """
    pstats_dict = {}
    func_list = self.fcn_list[:] if self.fcn_list else list(self.stats.keys())

    if not func_list:
        return pstats_dict

    pstats_dict["total_tt"] = float(f8(self.total_tt))
    for func in func_list:
        cc, nc, tt, ct, callers = self.stats[func]
        file, line, func_name = func
        ncalls = str(nc) if nc == cc else (str(nc) + '/' + str(cc))
        tottime = float(f8(tt))
        percall_tottime = -1 if nc == 0 else float(f8(tt/nc))
        cumtime = float(f8(ct))
        percall_cumtime = -1 if cc == 0 else float(f8(ct/cc))
        func_dict = {
            "ncalls": ncalls,
            "tottime": tottime, # time spent in this function alone
            "percall_tottime": percall_tottime,
            "cumtime": cumtime, # time spent in the function plus all functions that this function called,
            "percall_cumtime": percall_cumtime,
            "file_name": file,
            "line_number": line
        }
        func_dict_filtered = func_dict if not keys_filter else { key: func_dict[key] for key in keys_filter }
        pstats_dict[func_name] = func_dict_filtered

    return pstats_dict

pp = pprint.PrettyPrinter(depth=6)
pp.pprint(get_profile_dict(ps))
```

will produce:

```
{"<method 'disable' of '_lsprof.Profiler' objects>": {'cumtime': 0.0,
                                                      'file_name': '~',
                                                      'line_number': 0,
                                                      'ncalls': '1',
                                                      'percall_cumtime': 0.0,
                                                      'percall_tottime': 0.0,
                                                      'tottime': 0.0},
 'create_stats': {'cumtime': 0.0,
                  'file_name': '/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/cProfile.py',
                  'line_number': 50,
                  'ncalls': '1',
                  'percall_cumtime': 0.0,
                  'percall_tottime': 0.0,
                  'tottime': 0.0},
 'fib': {'cumtime': 0.0,
         'file_name': 'get_profile_dict.py',
         'line_number': 5,
         'ncalls': '15/1',
         'percall_cumtime': 0.0,
         'percall_tottime': 0.0,
         'tottime': 0.0},
 'total_tt': 0.0}
 ```

 As an example, this can be used to generate a stacked column chart using various visualization tools which will assist in easily identifying program bottlenecks.



https://bugs.python.org/issue37958



Automerge-Triggered-By: @gpshead
2020-01-15 14:51:54 -08:00
..
c-api bpo-39161: Document multi-phase init modules under Py_NewInterpreter() (GH-17896) 2020-01-09 04:05:18 -08:00
data bpo-38858: new_interpreter() reuses pycore_init_builtins() (GH-17351) 2019-11-22 19:24:49 +01:00
distributing Spell Bitbucket correctly. (GH-16862) 2019-10-23 12:17:30 +03:00
distutils bpo-38914 Do not require email field in setup.py. (GH-17388) 2019-12-23 06:53:18 -08:00
extending bpo-38600: NULL -> `NULL`. (GH-17001) 2019-10-30 21:37:16 +02:00
faq bpo-39136: Fixed typos (GH-17720) 2019-12-28 17:16:02 -05:00
howto Replace links in howto/pyporting.rst with sphinx references (GH-17781) 2020-01-05 17:08:14 -05:00
includes Minor C API documentation improvements. (GH-17696) 2019-12-24 22:25:56 -06:00
install Doc: Replace the deprecated highlightlang directive by highlight. (#13377) 2019-05-17 15:25:34 +05:30
installing Spell Bitbucket correctly. (GH-16862) 2019-10-23 12:17:30 +03:00
library bpo-37958: Adding get_profile_dict to pstats (GH-15495) 2020-01-15 14:51:54 -08:00
reference bpo-39048: Look up __aenter__ before __aexit__ in async with (GH-17609) 2020-01-14 21:58:29 +10:00
tools Doc: Change Python 2 status to EOL. (GH-17885) 2020-01-07 15:52:44 +09:00
tutorial bpo-38678: Improve argparse example in tutorial (GH-17207) 2019-11-17 22:06:19 -08:00
using bpo-38899: virtual environment activation for fish should use source (GH-17359) 2019-11-22 23:32:27 -08:00
whatsnew bpo-39329: Add timeout parameter for smtplib.LMTP constructor (GH-17998) 2020-01-14 22:42:09 +01:00
about.rst
bugs.rst Fix funny typo in Doc/bugs. (GH-15412) 2019-08-23 21:09:43 -07:00
conf.py Doc: Keep the venv/* exclude pattern. (GH-15229) 2019-08-26 02:11:43 -04:00
contents.rst
copyright.rst Bring Python into the next decade. (GH-17801) 2020-01-02 18:56:34 -08:00
glossary.rst bpo-39233: Update positional-only section in the glossary (GH-17874) 2020-01-08 05:00:14 -08:00
license.rst Bring Python into the next decade. (GH-17801) 2020-01-02 18:56:34 -08:00
make.bat bpo-39041: Add GitHub Actions support (GH-17594) 2019-12-16 10:35:22 -08:00
Makefile Bump Sphinx to 2.2.0. (GH-16532) 2019-10-22 18:13:41 +02:00
README.rst Doc: Add an optional obsolete header. (GH-13638) 2019-05-29 18:34:04 +02:00
requirements.txt Bump Sphinx to 2.2.0. (GH-16532) 2019-10-22 18:13:41 +02:00
runtime.txt bpo-37860: Add netlify deploy preview for docs (GH-15288) 2019-08-21 22:08:47 +09:00

Python Documentation README
~~~~~~~~~~~~~~~~~~~~~~~~~~~

This directory contains the reStructuredText (reST) sources to the Python
documentation.  You don't need to build them yourself, `prebuilt versions are
available <https://docs.python.org/dev/download.html>`_.

Documentation on authoring Python documentation, including information about
both style and markup, is available in the "`Documenting Python
<https://devguide.python.org/documenting/>`_" chapter of the
developers guide.


Building the docs
=================

The documentation is built with several tools which are not included in this
tree but are maintained separately and are available from
`PyPI <https://pypi.org/>`_.

* `Sphinx <https://pypi.org/project/Sphinx/>`_
* `blurb <https://pypi.org/project/blurb/>`_
* `python-docs-theme <https://pypi.org/project/python-docs-theme/>`_

The easiest way to install these tools is to create a virtual environment and
install the tools into there.

Using make
----------

To get started on UNIX, you can create a virtual environment with the command ::

  make venv

That will install all the tools necessary to build the documentation. Assuming
the virtual environment was created in the ``venv`` directory (the default;
configurable with the VENVDIR variable), you can run the following command to
build the HTML output files::

  make html

By default, if the virtual environment is not created, the Makefile will
look for instances of sphinxbuild and blurb installed on your process PATH
(configurable with the SPHINXBUILD and BLURB variables).

On Windows, we try to emulate the Makefile as closely as possible with a
``make.bat`` file. If you need to specify the Python interpreter to use,
set the PYTHON environment variable instead.

Available make targets are:

* "clean", which removes all build files.

* "venv", which creates a virtual environment with all necessary tools
  installed.

* "html", which builds standalone HTML files for offline viewing.

* "htmlview", which re-uses the "html" builder, but then opens the main page
  in your default web browser.

* "htmlhelp", which builds HTML files and a HTML Help project file usable to
  convert them into a single Compiled HTML (.chm) file -- these are popular
  under Microsoft Windows, but very handy on every platform.

  To create the CHM file, you need to run the Microsoft HTML Help Workshop
  over the generated project (.hhp) file.  The make.bat script does this for
  you on Windows.

* "latex", which builds LaTeX source files as input to "pdflatex" to produce
  PDF documents.

* "text", which builds a plain text file for each source file.

* "epub", which builds an EPUB document, suitable to be viewed on e-book
  readers.

* "linkcheck", which checks all external references to see whether they are
  broken, redirected or malformed, and outputs this information to stdout as
  well as a plain-text (.txt) file.

* "changes", which builds an overview over all versionadded/versionchanged/
  deprecated items in the current version. This is meant as a help for the
  writer of the "What's New" document.

* "coverage", which builds a coverage overview for standard library modules and
  C API.

* "pydoc-topics", which builds a Python module containing a dictionary with
  plain text documentation for the labels defined in
  `tools/pyspecific.py` -- pydoc needs these to show topic and keyword help.

* "suspicious", which checks the parsed markup for text that looks like
  malformed and thus unconverted reST.

* "check", which checks for frequent markup errors.

* "serve", which serves the build/html directory on port 8000.

* "dist", (Unix only) which creates distributable archives of HTML, text,
  PDF, and EPUB builds.


Without make
------------

First, install the tool dependencies from PyPI.

Then, from the ``Doc`` directory, run ::

   sphinx-build -b<builder> . build/<builder>

where ``<builder>`` is one of html, text, latex, or htmlhelp (for explanations
see the make targets above).

Deprecation header
==================

You can define the ``outdated`` variable in ``html_context`` to show a
red banner on each page redirecting to the "latest" version.

The link points to the same page on ``/3/``, sadly for the moment the
language is lost during the process.


Contributing
============

Bugs in the content should be reported to the
`Python bug tracker <https://bugs.python.org>`_.

Bugs in the toolset should be reported to the tools themselves.

You can also send a mail to the Python Documentation Team at docs@python.org,
and we will process your request as soon as possible.

If you want to help the Documentation Team, you are always welcome.  Just send
a mail to docs@python.org.