.. highlight:: rest

:mod:`sphinx.ext.autodoc` -- Include documentation from docstrings
==================================================================

.. module:: sphinx.ext.autodoc
   :synopsis: Include documentation from docstrings.

.. index:: pair: automatic; documentation
           single: docstring

This extension can import the modules you are documenting, and pull in
documentation from docstrings in a semi-automatic way.

For this to work, the docstrings must of course be written in correct
reStructuredText.  You can then use all of the usual Sphinx markup in the
docstrings, and it will end up correctly in the documentation.  Together with
hand-written documentation, this technique eases the pain of having to maintain
two locations for documentation, while at the same time avoiding
auto-generated-looking pure API documentation.

:mod:`autodoc` provides several directives that are versions of the usual
:dir:`module`, :dir:`class` and so forth.  On parsing time, they import the
corresponding module and extract the docstring of the given objects, inserting
them into the page source under a suitable :dir:`module`, :dir:`class` etc.
directive.

.. note::

   Just as :dir:`class` respects the current :dir:`module`, :dir:`autoclass`
   will also do so, and likewise with :dir:`method` and :dir:`class`.


.. directive:: automodule
               autoclass
               autoexception

   Document a module, class or exception.  All three directives will by default
   only insert the docstring of the object itself::

      .. autoclass:: Noodle

   will produce source like this::

      .. class:: Noodle

         Noodle's docstring.

   The "auto" directives can also contain content of their own, it will be
   inserted into the resulting non-auto directive source after the docstring
   (but before any automatic member documentation).

   Therefore, you can also mix automatic and non-automatic member documentation,
   like so::

      .. autoclass:: Noodle
         :members: eat, slurp

         .. method:: boil(time=10)

            Boil the noodle *time* minutes.

   **Options and advanced usage**
         
   * If you want to automatically document members, there's a ``members``
     option::

        .. autoclass:: Noodle
           :members:

     will document all non-private member functions and properties (that is,
     those whose name doesn't start with ``_``), while ::

        .. autoclass:: Noodle
           :members: eat, slurp

     will document exactly the specified members.

   * Members without docstrings will be left out, unless you give the
     ``undoc-members`` flag option::

        .. autoclass:: Noodle
           :members:
           :undoc-members:

   * For classes and exceptions, members inherited from base classes will be
     left out, unless you give the ``inherited-members`` flag option, in
     addition to ``members``::

        .. autoclass:: Noodle
           :members:
           :inherited-members:

     This can be combined with ``undoc-members`` to document *all* available
     members of the class or module.

     .. versionadded:: 0.3

   * It's possible to override the signature for callable members (functions,
     methods, classes) with the regular syntax that will override the signature
     gained from instropection::

        .. autoclass:: Noodle(type)

           .. automethod:: eat(persona)

     This is useful if the signature from the method is hidden by a decorator.

     .. versionadded:: 0.4

   * The :dir:`autoclass` and :dir:`autoexception` directives also support a
     flag option called ``show-inheritance``.  When given, a list of base
     classes will be inserted just below the class signature.

     .. versionadded:: 0.4

   * All autodoc directives support the ``noindex`` flag option that has the
     same effect as for standard :dir:`function` etc. directives: no index
     entries are generated for the documented object (and all autodocumented
     members).

     .. versionadded:: 0.4

   .. note::

      In an :dir:`automodule` directive with the ``members`` option set, only
      module members whose ``__module__`` attribute is equal to the module name
      as given to ``automodule`` will be documented.  This is to prevent
      documentation of imported classes or functions.


.. directive:: autofunction
               automethod
               autoattribute

   These work exactly like :dir:`autoclass` etc., but do not offer the options
   used for automatic member documentation.

   .. note::

      If you document decorated functions or methods, keep in mind that autodoc
      retrieves its docstrings by importing the module and inspecting the
      ``__doc__`` attribute of the given function or method.  That means that if
      a decorator replaces the decorated function with another, it must copy the
      original ``__doc__`` to the new function.

      From Python 2.5, :func:`functools.wraps` can be used to create
      well-behaved decorating functions.


There are also new config values that you can set:

.. confval:: automodule_skip_lines

   This value (whose default is ``0``) can be used to skip an amount of lines in
   every module docstring that is processed by an :dir:`automodule` directive.
   This is provided because some projects like to put headings in the module
   docstring, which would then interfere with your sectioning, or automatic
   fields with version control tags, that you don't want to put in the generated
   documentation.

   .. deprecated:: 0.4
      Use the more versatile docstring processing provided by
      :event:`autodoc-process-docstring`.

.. confval:: autoclass_content

   This value selects what content will be inserted into the main body of an
   :dir:`autoclass` directive.  The possible values are:

   ``"class"``
      Only the class' docstring is inserted.  This is the default.  You can
      still document ``__init__`` as a separate method using :dir:`automethod`
      or the ``members`` option to :dir:`autoclass`.
   ``"both"``
      Both the class' and the ``__init__`` method's docstring are concatenated
      and inserted.
   ``"init"``
      Only the ``__init__`` method's docstring is inserted.

   .. versionadded:: 0.3


Docstring preprocessing
-----------------------

.. versionadded:: 0.4

autodoc provides the following additional event:

.. event:: autodoc-process-docstring (app, what, name, obj, options, lines)

   Emitted when autodoc has read and processed a docstring.  *lines* is a list
   of strings -- the lines of the processed docstring -- that the event handler
   can modify **in place** to change what Sphinx puts into the output.

   :param app: the Sphinx application object
   :param what: the type of the object which the docstring belongs to (one of
      ``"module"``, ``"class"``, ``"exception"``, ``"function"``, ``"method"``,
      ``"attribute"``)
   :param name: the fully qualified name of the object
   :param obj: the object itself
   :param options: the options given to the directive: an object with attributes
      ``inherited_members``, ``undoc_members``, ``show_inheritance`` and
      ``noindex`` that are true if the flag option of same name was given to the
      auto directive
   :param lines: the lines of the docstring, see above


The :mod:`sphinx.ext.autodoc` module provides factory functions for commonly
needed docstring processing:

.. autofunction:: cut_lines
.. autofunction:: between
