Sphinx & reStructuredText & docstring

Last modified on 01 Oct 2021.

Install
Folder structure
Build
Format
Autodoc from python library
- Problem of “Attributes”
- Problem with decorator
Docstring
Errors
References

Install

# install python first
pip install sphinx
pip install sphinx-autobuild
pip install sphinx_rtd_theme
pip install sphinxcontrib-napoleon # theme

Folder structure

|-- project
    |-- custom_lib # python package
    |-- custom_lib-doc
        |-- source
            |-- conf.py

# conf.py
import os, sys
import sphinx_rtd_theme
import sphinxcontrib

path_custom_lib = os.path.abspath('../../')
sys.path.append(path_custom_lib)

project = 'My notes'
copyright = '2020, Math2IT'
author = 'Anh-Thi DINH'
release = '0.2'

extensions = [
    'sphinxcontrib.napoleon',
    'sphinx_rtd_theme',
    'sphinx.ext.mathjax'
]

napoleon_include_init_with_doc = True
napoleon_google_docstring = True
napoleon_use_param = True
napoleon_use_ivar = True

html_theme = 'sphinx_rtd_theme'

html_theme_options = {
    'display_version': True,
    'prev_next_buttons_location': 'both',
    'style_external_links': True,
    'style_nav_header_background': '#F5A603',
    'sticky_navigation': True,
    'navigation_depth': 4,
}

Build

# folder structure
|-- project
    |-- custom_lib
    |-- custom_lib-doc
        |-- source
            |-- conf.py

# build
sphinx-build source build

# auto build + watch the change
sphinx-autobuild source _local -p 8555
# http://127.0.0.1:8555/

Format

Headings

H1 heading
==========

H2 heading
----------

H3 heading
..........

H4 heading
~~~~~~~~~~

Link

Cross url (in the same document)^[ref]

# place to ref
:ref:`custum text<CSVLoader>`.

# Display "CSV"
:ref:`CSVLoader`

# somewhere
.. _CSVLoader:

CSV
===

# if heading inside the same file as the caller
Call to `Name of heading`_

Name of heading
===============

External urls:

External hyperlinks, like Python_.

.. _Python: http://www.python.org/

# or inline
`Python <http://www.python.org/>`_.

External hyperlinks, like `About Python`_.

.. _About Python: http://www.python.org/

To a class, method,… in the python library (this question -> ref),

:py:meth:`mymodule.MyClass.mymethod`

# or even shorter (if python is default)
:meth:`mymodule.MyClass.mymethod`

# custom text
:py:meth:`custom text<mymodule.MyClass.mymethod>`

:class:: for classes.

Alert boxes

# note
.. note:: First paragraph.

    Second paragraph.

# warning
.. warning:: Content of the warning.

Insert images

# block
.. image:: images/ball1.gif

# inline
The |biohazard| symbol.

.. |biohazard| image:: biohazard.png

Insrt code

# without syntax highlight
::

    def abc():
        pass

# with syntax highlight
.. code-block:: python

    def abc():
        pass

Autodoc from python library

👉 Main ref.

# folder structure
|-- project
    |-- custom_lib
    |-- custom_lib-doc
        |-- source
            |-- conf.py

# conf.py
import os
import sys

path_custom_lib = os.path.abspath('../../')
sys.path.append(path_custom_lib)

# all classes in classes.py
.. automodule:: custom_lib.folder.classes
   :members:

# in case `fit`, `predict` didn't show
.. automodule:: custom_lib.folder.classes
   :members:
   :undoc-members:

# a specific class in classes.py
.. autoclass:: custom_lib.folder.classes.ClassA
   :members:

Problem of “Attributes”

When we use "Attributes" in docstring, the sphinx (sphinx_rtd_theme template) will render it as "Variables" if we indicate napoleon_use_ivar = True in the config. (check this issue)
List of supported section headers in docstring.
Read this blog as an option. It works for Google Docstring, not numpy docstring yet!

Problem with decorator

Sphinx doesn’t render docstring for classes coming with decorator, i.e. @something (before def). We can’t use only :members:.

from functools import wraps
def my_decorator(f):
    @wraps(f)
    def wrapper(*args, **kwds):
        """Doc from wrapper"""
        print('Calling decorated function')
        return f(*args, **kwds)
    return wrapper

@my_decorator
def example():
    """Docstring"""
    print('Called example function')

example.__doc__ # with @wraps(f)

example.__doc__ # without @wraps(f)

'Docstring'

'Doc from wrapper'

Docstring

What?

If you wanna make a docstring (showing the information of a function when using help(<func>) or func.__doc__).

def reverse(text):
    """Reverse a text.
    Input the text.
    Return text reversed.
    """
    return text[::-1]

help(reverse)

Help on function reverse in module __main__:

reverse(text)
    Reverse a text.
    Input the text.
    Return text reversed.

reverse.__doc__

print(reverse.__doc__)

'Reverse a text.\n    Input the text.\n    Return text reversed.\n    '

Reverse a text.
    Input the text.
    Return text reversed.

Numpy Style

👉 Official docs.
👉 Example of numpy docstring with sphinx.

An overview example,

def ex_class(var1, var2):
    """
    Quick description.
    Longer description with `keywords`.

    Parameters
    ----------
    var1 : int
        Desc for var1.
    var2 : {0 or 'index', 1 or 'columns'}, default 0
        Long desc for var2. It may take a long line and we can break
        this like that.

    Returns
    -------
    Resampler object

    See Also
    --------
    groupby : Group by mapping, function, label, or list of labels.
    Series.resample : Resample a Series.

    Notes
    -----
    See the `user guide
    <https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#resampling>`_
    for more.

    Examples
    --------
    Start by creating a series with 9 one minute timestamps.
    >>> index = 1 +1
    2
    Description for this example.
    """
    # some commands
    return return_values

Quick description.
Longer description with `keywords`.

Parameters
----------
var1 : int
    Desc for var1.
var2 : {0 or 'index', 1 or 'columns'}, default 0
    Long desc for var2. It may take a long line and we can break
    this like that.

Returns
-------
Resampler object

See Also
--------
groupby : Group by mapping, function, label, or list of labels.
Series.resample : Resample a Series.

Notes
-----
See the `user guide
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#resampling>`_
for more.

Examples
--------
Start by creating a series with 9 one minute timestamps.
>>> index = 1 +1
2
Description for this example.

Math equations,

# inline equation
"""
.. math:: \\drac{1}{2}
"""

# break very long equation
"""
.. math::
    x_{\\text{min}} + \\dfrac{1}
    {2} # for a very long equation
"""

# aligned
"""
.. math::
    x+y &= z

    1+2 &= 3
"""

# cases
"""
.. math::
    f(x) = \smash{
        \\begin{cases}
        0, &\\text{ if } x < 40, \\\\
        1, & \\text{ if } 40 \leq x <60, \\\\
        \\end{cases}
    }
"""

# Methof, url.
"""
Instantiate the class.

Parameters
----------
lst_comparison_type: str, default "wasserstein"
    Type of comparison. The supported types are in `dict_tests` which
    contains:

    - "pearsonr": `Pearson correlation coefficient
      <https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.pearsonr.html>`_.

    - "wasserstein": Wasserstein distance (earth mover's distance). It
      measures the distance between 2 distributions.
      Check :meth:`popai.distribution_wasserstein_score`.
"""

# long line url
"""
- "pearsonr": `Pearson correlation coefficient
  <https://docs.scipy.org/doc/scipy/reference/\
generated/scipy.stats.pearsonr.html>`_.
"""

# single returns
"""
Returns
-------
tuple (float, dict)
    Description.
"""

# return a tuple
"""
Returns
-------
reject : ndarray, boolean
    Description.
pvals_corrected : ndarray
    p-Description.
"""

# break lines in itemize
"""
Returns
-------
info: dict
    Description.

    - Item 1.
    - Item 2 very long lines
      can be broken here.
"""

Google Style Python Docstring

👉 Example Google Style Python Docstrings — napoleon 0.7 documentation
👉 styleguide | Style guides for Google-originated open-source projects

# function
"""
Args:
    param1 (int): The first parameter.
    param2 (str): The second parameter.

Returns:
    bool: The return value. True for success, False otherwise.
"""

Errors

Problems with VSCode which cannot run the preview:

Select and activate an environment, Ctrl + Shift + P then choose Python: Select Interpreter then choose the right version of python you wanna run the docs on.
Make sure the conda is already in $PATH + update the bashrc or zshrc (try conda --version).
Make sure the right environement is activate in VSCode + all necessary libs are already istalled!

References

Rest and Sphinx Memo.
docutils – Quick ref to rst format.
Thomas Cokelaer – Sphinx and RST syntax guide
Sam Nicholls – An idiot’s guide to Python documentation with Sphinx and ReadTheDocs
sphinx-doc – Include documentation from docstrings
Sphinx configuration.

^•Notes with this notation aren't good enough. They are being updated. If you can see this, you are so smart. ;)