:mod:`sphinx.ext.napoleon` -- Support for NumPy and Google style docstrings =========================================================================== .. module:: sphinx.ext.napoleon :synopsis: Support for NumPy and Google style docstrings .. moduleauthor:: Rob Ruana .. versionadded:: 1.3 Overview -------- .. highlight:: text Are you tired of writing docstrings that look like this:: :param path: The path of the file to wrap :type path: str :param field_storage: The :class:`FileStorage` instance to wrap :type field_storage: FileStorage :param temporary: Whether or not to delete the file when the File instance is destructed :type temporary: bool :returns: A buffered writable file descriptor :rtype: BufferedFileStorage `reStructuredText`_ is great, but it creates visually dense, hard to read :pep:`docstrings <287>`. Compare the jumble above to the same thing rewritten according to the `Google Python Style Guide`_:: Args: path (str): The path of the file to wrap field_storage (FileStorage): The :class:`FileStorage` instance to wrap temporary (bool): Whether or not to delete the file when the File instance is destructed Returns: BufferedFileStorage: A buffered writable file descriptor Much more legible, no? Napoleon is a :term:`extension` that enables Sphinx to parse both `NumPy`_ and `Google`_ style docstrings - the style recommended by `Khan Academy`_. Napoleon is a pre-processor that parses `NumPy`_ and `Google`_ style docstrings and converts them to reStructuredText before Sphinx attempts to parse them. This happens in an intermediate step while Sphinx is processing the documentation, so it doesn't modify any of the docstrings in your actual source code files. .. _ReStructuredText: https://docutils.sourceforge.io/rst.html .. _Google Python Style Guide: https://google.github.io/styleguide/pyguide.html .. _Google: https://google.github.io/styleguide/pyguide.html#38-comments-and-docstrings .. _NumPy: https://numpydoc.readthedocs.io/en/latest/format.html#docstring-standard .. _Khan Academy: https://github.com/Khan/style-guides/blob/master/style/python.md#docstrings Getting Started ~~~~~~~~~~~~~~~ 1. After :doc:`setting up Sphinx ` to build your docs, enable napoleon in the Sphinx ``conf.py`` file:: # conf.py # Add napoleon to the extensions list extensions = ['sphinx.ext.napoleon'] 2. Use ``sphinx-apidoc`` to build your API documentation:: $ sphinx-apidoc -f -o docs/source projectdir Docstrings ~~~~~~~~~~ Napoleon interprets every docstring that :mod:`autodoc ` can find, including docstrings on: ``modules``, ``classes``, ``attributes``, ``methods``, ``functions``, and ``variables``. Inside each docstring, specially formatted `Sections`_ are parsed and converted to reStructuredText. All standard reStructuredText formatting still works as expected. .. _Sections: Docstring Sections ~~~~~~~~~~~~~~~~~~ All of the following section headers are supported: * ``Args`` *(alias of Parameters)* * ``Arguments`` *(alias of Parameters)* * ``Attention`` * ``Attributes`` * ``Caution`` * ``Danger`` * ``Error`` * ``Example`` * ``Examples`` * ``Hint`` * ``Important`` * ``Keyword Args`` *(alias of Keyword Arguments)* * ``Keyword Arguments`` * ``Methods`` * ``Note`` * ``Notes`` * ``Other Parameters`` * ``Parameters`` * ``Return`` *(alias of Returns)* * ``Returns`` * ``Raise`` *(alias of Raises)* * ``Raises`` * ``References`` * ``See Also`` * ``Tip`` * ``Todo`` * ``Warning`` * ``Warnings`` *(alias of Warning)* * ``Warn`` *(alias of Warns)* * ``Warns`` * ``Yield`` *(alias of Yields)* * ``Yields`` Google vs NumPy ~~~~~~~~~~~~~~~ Napoleon supports two styles of docstrings: `Google`_ and `NumPy`_. The main difference between the two styles is that Google uses indentation to separate sections, whereas NumPy uses underlines. Google style: .. code-block:: python def func(arg1, arg2): """Summary line. Extended description of function. Args: arg1 (int): Description of arg1 arg2 (str): Description of arg2 Returns: bool: Description of return value """ return True NumPy style: .. code-block:: python def func(arg1, arg2): """Summary line. Extended description of function. Parameters ---------- arg1 : int Description of arg1 arg2 : str Description of arg2 Returns ------- bool Description of return value """ return True NumPy style tends to require more vertical space, whereas Google style tends to use more horizontal space. Google style tends to be easier to read for short and simple docstrings, whereas NumPy style tends be easier to read for long and in-depth docstrings. The choice between styles is largely aesthetic, but the two styles should not be mixed. Choose one style for your project and be consistent with it. .. seealso:: For complete examples: * :ref:`example_google` * :ref:`example_numpy` Type Annotations ~~~~~~~~~~~~~~~~ :pep:`484` introduced a standard way to express types in Python code. This is an alternative to expressing types directly in docstrings. One benefit of expressing types according to :pep:`484` is that type checkers and IDEs can take advantage of them for static code analysis. :pep:`484` was then extended by :pep:`526` which introduced a similar way to annotate variables (and attributes). Google style with Python 3 type annotations:: def func(arg1: int, arg2: str) -> bool: """Summary line. Extended description of function. Args: arg1: Description of arg1 arg2: Description of arg2 Returns: Description of return value """ return True class Class: """Summary line. Extended description of class Attributes: attr1: Description of attr1 attr2: Description of attr2 """ attr1: int attr2: str Google style with types in docstrings:: def func(arg1, arg2): """Summary line. Extended description of function. Args: arg1 (int): Description of arg1 arg2 (str): Description of arg2 Returns: bool: Description of return value """ return True class Class: """Summary line. Extended description of class Attributes: attr1 (int): Description of attr1 attr2 (str): Description of attr2 """ .. Note:: `Python 2/3 compatible annotations`_ aren't currently supported by Sphinx and won't show up in the docs. .. _Python 2/3 compatible annotations: https://peps.python.org/pep-0484/#suggested-syntax-for-python-2-7-and-straddling-code Configuration ------------- Listed below are all the settings used by napoleon and their default values. These settings can be changed in the Sphinx ``conf.py`` file. Make sure that "sphinx.ext.napoleon" is enabled in ``conf.py``:: # conf.py # Add any Sphinx extension module names here, as strings extensions = ['sphinx.ext.napoleon'] # Napoleon settings napoleon_google_docstring = True napoleon_numpy_docstring = True napoleon_include_init_with_doc = False napoleon_include_private_with_doc = False napoleon_include_special_with_doc = True napoleon_use_admonition_for_examples = False napoleon_use_admonition_for_notes = False napoleon_use_admonition_for_references = False napoleon_use_ivar = False napoleon_use_param = True napoleon_use_rtype = True napoleon_preprocess_types = False napoleon_type_aliases = None napoleon_attr_annotations = True .. _Google style: https://google.github.io/styleguide/pyguide.html#38-comments-and-docstrings .. _NumPy style: https://numpydoc.readthedocs.io/en/latest/format.html#docstring-standard .. confval:: napoleon_google_docstring True to parse `Google style`_ docstrings. False to disable support for Google style docstrings. *Defaults to True.* .. confval:: napoleon_numpy_docstring True to parse `NumPy style`_ docstrings. False to disable support for NumPy style docstrings. *Defaults to True.* .. confval:: napoleon_include_init_with_doc True to list ``__init___`` docstrings separately from the class docstring. False to fall back to Sphinx's default behavior, which considers the ``__init___`` docstring as part of the class documentation. *Defaults to False.* **If True**:: def __init__(self): """ This will be included in the docs because it has a docstring """ def __init__(self): # This will NOT be included in the docs .. confval:: napoleon_include_private_with_doc True to include private members (like ``_membername``) with docstrings in the documentation. False to fall back to Sphinx's default behavior. *Defaults to False.* **If True**:: def _included(self): """ This will be included in the docs because it has a docstring """ pass def _skipped(self): # This will NOT be included in the docs pass .. confval:: napoleon_include_special_with_doc True to include special members (like ``__membername__``) with docstrings in the documentation. False to fall back to Sphinx's default behavior. *Defaults to True.* **If True**:: def __str__(self): """ This will be included in the docs because it has a docstring """ return unicode(self).encode('utf-8') def __unicode__(self): # This will NOT be included in the docs return unicode(self.__class__.__name__) .. confval:: napoleon_use_admonition_for_examples True to use the ``.. admonition::`` directive for the **Example** and **Examples** sections. False to use the ``.. rubric::`` directive instead. One may look better than the other depending on what HTML theme is used. *Defaults to False.* This `NumPy style`_ snippet will be converted as follows:: Example ------- This is just a quick example **If True**:: .. admonition:: Example This is just a quick example **If False**:: .. rubric:: Example This is just a quick example .. confval:: napoleon_use_admonition_for_notes True to use the ``.. admonition::`` directive for **Notes** sections. False to use the ``.. rubric::`` directive instead. *Defaults to False.* .. note:: The singular **Note** section will always be converted to a ``.. note::`` directive. .. seealso:: :confval:`napoleon_use_admonition_for_examples` .. confval:: napoleon_use_admonition_for_references True to use the ``.. admonition::`` directive for **References** sections. False to use the ``.. rubric::`` directive instead. *Defaults to False.* .. seealso:: :confval:`napoleon_use_admonition_for_examples` .. confval:: napoleon_use_ivar True to use the ``:ivar:`` role for instance variables. False to use the ``.. attribute::`` directive instead. *Defaults to False.* This `NumPy style`_ snippet will be converted as follows:: Attributes ---------- attr1 : int Description of `attr1` **If True**:: :ivar attr1: Description of `attr1` :vartype attr1: int **If False**:: .. attribute:: attr1 Description of `attr1` :type: int .. confval:: napoleon_use_param True to use a ``:param:`` role for each function parameter. False to use a single ``:parameters:`` role for all the parameters. *Defaults to True.* This `NumPy style`_ snippet will be converted as follows:: Parameters ---------- arg1 : str Description of `arg1` arg2 : int, optional Description of `arg2`, defaults to 0 **If True**:: :param arg1: Description of `arg1` :type arg1: str :param arg2: Description of `arg2`, defaults to 0 :type arg2: :class:`int`, *optional* **If False**:: :parameters: * **arg1** (*str*) -- Description of `arg1` * **arg2** (*int, optional*) -- Description of `arg2`, defaults to 0 .. confval:: napoleon_use_keyword True to use a ``:keyword:`` role for each function keyword argument. False to use a single ``:keyword arguments:`` role for all the keywords. *Defaults to True.* This behaves similarly to :confval:`napoleon_use_param`. Note unlike docutils, ``:keyword:`` and ``:param:`` will not be treated the same way - there will be a separate "Keyword Arguments" section, rendered in the same fashion as "Parameters" section (type links created if possible) .. seealso:: :confval:`napoleon_use_param` .. confval:: napoleon_use_rtype True to use the ``:rtype:`` role for the return type. False to output the return type inline with the description. *Defaults to True.* This `NumPy style`_ snippet will be converted as follows:: Returns ------- bool True if successful, False otherwise **If True**:: :returns: True if successful, False otherwise :rtype: bool **If False**:: :returns: *bool* -- True if successful, False otherwise .. confval:: napoleon_preprocess_types True to convert the type definitions in the docstrings as references. Defaults to *False*. .. versionadded:: 3.2.1 .. versionchanged:: 3.5 Do preprocess the Google style docstrings also. .. confval:: napoleon_type_aliases A mapping to translate type names to other names or references. Works only when ``napoleon_use_param = True``. *Defaults to None.* With:: napoleon_type_aliases = { "CustomType": "mypackage.CustomType", "dict-like": ":term:`dict-like `", } This `NumPy style`_ snippet:: Parameters ---------- arg1 : CustomType Description of `arg1` arg2 : dict-like Description of `arg2` becomes:: :param arg1: Description of `arg1` :type arg1: mypackage.CustomType :param arg2: Description of `arg2` :type arg2: :term:`dict-like ` .. versionadded:: 3.2 .. confval:: napoleon_attr_annotations True to allow using :pep:`526` attributes annotations in classes. If an attribute is documented in the docstring without a type and has an annotation in the class body, that type is used. .. versionadded:: 3.4 .. confval:: napoleon_custom_sections Add a list of custom sections to include, expanding the list of parsed sections. *Defaults to None.* The entries can either be strings or tuples, depending on the intention: * To create a custom "generic" section, just pass a string. * To create an alias for an existing section, pass a tuple containing the alias name and the original, in that order. * To create a custom section that displays like the parameters or returns section, pass a tuple containing the custom section name and a string value, "params_style" or "returns_style". If an entry is just a string, it is interpreted as a header for a generic section. If the entry is a tuple/list/indexed container, the first entry is the name of the section, the second is the section key to emulate. If the second entry value is "params_style" or "returns_style", the custom section will be displayed like the parameters section or returns section. .. versionadded:: 1.8 .. versionchanged:: 3.5 Support ``params_style`` and ``returns_style``