.. 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.

.. note::

   For Sphinx (actually, the Python interpreter that executes Sphinx) to find
   your module, it must be importable.  That means that the module or the
   package must be in one of the directories on :data:`sys.path` -- adapt your
   :data:`sys.path` in the configuration file accordingly.

.. warning::

   :mod:`~sphinx.ext.autodoc` **imports** the modules to be documented.  If any
   modules have side effects on import, these will be executed by ``autodoc``
   when ``sphinx-build`` is run.

   If you document scripts (as opposed to library modules), make sure their main
   routine is protected by a ``if __name__ == '__main__'`` condition.

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.

If you prefer `NumPy`_ or `Google`_ style docstrings over reStructuredText,
you can also enable the :mod:`napoleon <sphinx.ext.napoleon>` extension.
:mod:`napoleon <sphinx.ext.napoleon>` is a preprocessor that converts your
docstrings to correct reStructuredText before :mod:`autodoc` processes them.

.. _Google:
   https://google.github.io/styleguide/pyguide.html#Comments
.. _NumPy:
   https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt

:mod:`autodoc` provides several directives that are versions of the usual
:rst:dir:`py:module`, :rst:dir:`py: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 :rst:dir:`py:module`,
:rst:dir:`py:class` etc.  directive.

.. note::

   Just as :rst:dir:`py:class` respects the current :rst:dir:`py:module`,
   :rst:dir:`autoclass` will also do so.  Likewise, :rst:dir:`automethod` will
   respect the current :rst:dir:`py:class`.


.. rst: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::

        .. automodule:: noodle
           :members:

     will document all module members (recursively), and ::

        .. autoclass:: Noodle
           :members:

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

     For modules, ``__all__`` will be respected when looking for members; the
     order of the members will also be the order in ``__all__``.

     You can also give an explicit list of members; only these will then be
     documented::

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

   * If you want to make the ``members`` option (or other flag options described
     below) the default, see :confval:`autodoc_default_flags`.

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

        .. automodule:: noodle
           :members:
           :undoc-members:

   * "Private" members (that is, those named like ``_private`` or ``__private``)
     will be included if the ``private-members`` flag option is given.

     .. versionadded:: 1.1

   * Python "special" members (that is, those named like ``__special__``) will
     be included if the ``special-members`` flag option is given::

        .. autoclass:: my.Class
           :members:
           :private-members:
           :special-members:

     would document both "private" and "special" members of the class.

     .. versionadded:: 1.1

     .. versionchanged:: 1.2
        The option can now take arguments, i.e. the special members to document.

   * For classes and exceptions, members inherited from base classes will be
     left out when documenting all members, 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.

     Note: this will lead to markup errors if the inherited members come from a
     module whose docstrings are not reST formatted.

     .. versionadded:: 0.3

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

        .. autoclass:: Noodle(type)

           .. automethod:: eat(persona)

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

     .. versionadded:: 0.4

   * The :rst:dir:`automodule`, :rst:dir:`autoclass` and
     :rst: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 (when used with :rst:dir:`automodule`, this
     will be inserted for every class that is documented in the module).

     .. versionadded:: 0.4

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

     .. versionadded:: 0.4

   * :rst:dir:`automodule` also recognizes the ``synopsis``, ``platform`` and
     ``deprecated`` options that the standard :rst:dir:`py:module` directive
     supports.

     .. versionadded:: 0.5

   * :rst:dir:`automodule` and :rst:dir:`autoclass` also has an ``member-order``
     option that can be used to override the global value of
     :confval:`autodoc_member_order` for one directive.

     .. versionadded:: 0.6

   * The directives supporting member documentation also have a
     ``exclude-members`` option that can be used to exclude single member names
     from documentation, if all members are to be documented.

     .. versionadded:: 0.6

   * In an :rst: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.  Set the
     ``imported-members`` option if you want to prevent this behavior and
     document all available members.  Note that attributes from imported modules
     will not be documented, because attribute documentation is discovered by
     parsing the source file of the current module.

     .. versionadded:: 1.2

   * Add a list of modules in the :confval:`autodoc_mock_imports` to prevent
     import errors to halt the building process when some external dependencies
     are not importable at build time.

     .. versionadded:: 1.3


.. rst:directive:: autofunction
                   autodata
                   automethod
                   autoattribute

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

   :rst:dir:`autodata` and :rst:dir:`autoattribute` support
   the ``annotation`` option.
   Without this option, the representation of the object
   will be shown in the documentation.
   When the option is given without arguments,
   only the name of the object will be printed::

      .. autodata:: CD_DRIVE
         :annotation:

   You can tell sphinx what should be printed after the name::

      .. autodata:: CD_DRIVE
         :annotation: = your CD device name

   For module data members and class attributes, documentation can either be put
   into a comment with special formatting (using a ``#:`` to start the comment
   instead of just ``#``), or in a docstring *after* the definition.  Comments
   need to be either on a line of their own *before* the definition, or
   immediately after the assignment *on the same line*.  The latter form is
   restricted to one line only.

   This means that in the following class definition, all attributes can be
   autodocumented::

      class Foo:
          """Docstring for class Foo."""

          #: Doc comment for class attribute Foo.bar.
          #: It can have multiple lines.
          bar = 1

          flox = 1.5   #: Doc comment for Foo.flox. One line only.

          baz = 2
          """Docstring for class attribute Foo.baz."""

          def __init__(self):
              #: Doc comment for instance attribute qux.
              self.qux = 3

              self.spam = 4
              """Docstring for instance attribute spam."""

   .. versionchanged:: 0.6
      :rst:dir:`autodata` and :rst:dir:`autoattribute` can now extract
      docstrings.
   .. versionchanged:: 1.1
      Comment docs are now allowed on the same line after an assignment.

   .. versionchanged:: 1.2
      :rst:dir:`autodata` and :rst:dir:`autoattribute` have an ``annotation``
      option.

   .. 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:: autoclass_content

   This value selects what content will be inserted into the main body of an
   :rst: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
      :rst:dir:`automethod` or the ``members`` option to :rst: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

   If the class has no ``__init__`` method or if the ``__init__`` method's
   docstring is empty, but the class has a ``__new__`` method's docstring,
   it is used instead.

   .. versionadded:: 1.4

.. confval:: autodoc_member_order

   This value selects if automatically documented members are sorted
   alphabetical (value ``'alphabetical'``), by member type (value
   ``'groupwise'``) or by source order (value ``'bysource'``).  The default is
   alphabetical.

   Note that for source order, the module must be a Python module with the
   source code available.

   .. versionadded:: 0.6
   .. versionchanged:: 1.0
      Support for ``'bysource'``.

.. confval:: autodoc_default_flags

   This value is a list of autodoc directive flags that should be automatically
   applied to all autodoc directives.  The supported flags are ``'members'``,
   ``'undoc-members'``, ``'private-members'``, ``'special-members'``,
   ``'inherited-members'`` and ``'show-inheritance'``.

   If you set one of these flags in this config value, you can use a negated
   form, :samp:`'no-{flag}'`, in an autodoc directive, to disable it once.
   For example, if ``autodoc_default_flags`` is set to ``['members',
   'undoc-members']``, and you write a directive like this::

      .. automodule:: foo
         :no-undoc-members:

   the directive will be interpreted as if only ``:members:`` was given.

   .. versionadded:: 1.0

.. confval:: autodoc_docstring_signature

   Functions imported from C modules cannot be introspected, and therefore the
   signature for such functions cannot be automatically determined.  However, it
   is an often-used convention to put the signature into the first line of the
   function's docstring.

   If this boolean value is set to ``True`` (which is the default), autodoc will
   look at the first line of the docstring for functions and methods, and if it
   looks like a signature, use the line as the signature and remove it from the
   docstring content.

   .. versionadded:: 1.1

.. confval:: autodoc_mock_imports

   This value contains a list of modules to be mocked up. This is useful when
   some external dependencies are not met at build time and break the building
   process. You may only specify the root package of the dependencies
   themselves and ommit the sub-modules:

   .. code-block:: python

      autodoc_mock_imports = ["django"]

   Will mock all imports under the ``django`` package.

   .. versionadded:: 1.3

   .. versionchanged:: 1.6
      This config value only requires to declare the top-level modules that
      should be mocked.

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

autodoc provides the following additional events:

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

   .. versionadded:: 0.4

   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

.. event:: autodoc-process-signature (app, what, name, obj, options, signature, return_annotation)

   .. versionadded:: 0.5

   Emitted when autodoc has formatted a signature for an object. The event
   handler can return a new tuple ``(signature, return_annotation)`` 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 signature: function signature, as a string of the form
      ``"(parameter_1, parameter_2)"``, or ``None`` if introspection didn't
      succeed and signature wasn't specified in the directive.
   :param return_annotation: function return annotation as a string of the form
      ``" -> annotation"``, or ``None`` if there is no return annotation

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

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


Skipping members
----------------

autodoc allows the user to define a custom method for determining whether a
member should be included in the documentation by using the following event:

.. event:: autodoc-skip-member (app, what, name, obj, skip, options)

   .. versionadded:: 0.5

   Emitted when autodoc has to decide whether a member should be included in the
   documentation.  The member is excluded if a handler returns ``True``.  It is
   included if the handler returns ``False``.

   If more than one enabled extension handles the ``autodoc-skip-member``
   event, autodoc will use the first non-``None`` value returned by a handler.
   Handlers should return ``None`` to fall back to the skipping behavior of
   autodoc and other enabled extensions.

   :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 skip: a boolean indicating if autodoc will skip this member if the
      user handler does not override the decision
   :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
