Sphinx

# The Python Domain

Added in version 1.0.

The Python domain (name py) provides the following directives for module declarations:

.. py:module:: name

  This directive marks the beginning of the description of a module (or package submodule, in which case the name should be fully qualified, including the package name). A description of the module such as the docstring can be placed in the body of the directive.

  This directive will also cause an entry in the global module index.

  Changed in version 5.2: Module directives support body content.

  options

  :platform: platforms (comma separated list)

    Indicate platforms which the module is available (if it is available on all platforms, the option should be omitted). The keys are short identifiers; examples that are in use include “IRIX”, “Mac”, “Windows” and “Unix”. It is important to use a key which has already been used when applicable.

  :synopsis: purpose (text)

    Consist of one sentence describing the module’s purpose – it is currently only used in the Global Module Index.

  :deprecated: (no argument)

    Mark a module as deprecated; it will be designated as such in various locations then.

.. py:currentmodule:: name

  This directive tells Sphinx that the classes, functions etc. documented from here are in the given module (like `py:module`), but it will not create index entries, an entry in the Global Module Index, or a link target for `py:mod`. This is helpful in situations where documentation for things in a module is spread over multiple files or sections – one location has the `py:module` directive, the others only `py:currentmodule`.

The following directives are provided for module and class contents:

.. py:function:: name(parameters)
.. py:function:: name[type parameters](parameters)

  Describes a module-level function. The signature should include the parameters, together with optional type parameters, as given in the Python function definition, see Python Signatures. For example:

      .. py:function:: Timer.repeat(repeat=3, number=1_000_000)
      .. py:function:: add[T](a: T, b: T) -> T

  For methods you should use `py:method`.

  The description normally includes information about the parameters required and how they are used (especially whether mutable objects passed as parameters are modified), side effects, and possible exceptions.

  This information can (in any `py` directive) optionally be given in a structured form, see Info field lists.

  options

  :async: (no value)

    Indicate the function is an async function.

    Added in version 2.1.

  :canonical: (full qualified name including module name)

    Describe the location where the object is defined if the object is imported from other modules

    Added in version 4.0.

  :single-line-parameter-list: (no value)

    Ensures that the function’s arguments will be emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

    Added in version 7.1.

  :single-line-type-parameter-list: (no value)

    Ensure that the function’s type parameters are emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

    Added in version 7.1.

.. py:data:: name

  Describes global data in a module, including both variables and values used as “defined constants.” Consider using `py:type` for type aliases instead and `py:attribute` for class variables and instance attributes.

  options

  :type: type of the variable (text)

    This will be parsed as a Python expression for cross-referencing the type annotation. As such, the argument to `:type:` should be a valid annotation expression.

    Caution

    The valid syntax for the `:type:` directive option differs from the syntax for the `:type:` info field. The `:type:` directive option does not understand reStructuredText markup or the `or` or `of` keywords, meaning unions must use `|` and sequences must use square brackets, and roles such as `:ref:`...`` cannot be used.

    Added in version 2.4.

  :value: initial value of the variable (text)

    Added in version 2.4.

  :canonical: (full qualified name including module name)

    Describe the location where the object is defined if the object is imported from other modules

    Added in version 4.0.

.. py:exception:: name
.. py:exception:: name(parameters)
.. py:exception:: name[type parameters](parameters)

  Describes an exception class. The signature can, but need not include parentheses with constructor arguments, or may optionally include type parameters (see PEP 695).

  options

  :final: (no value)

    Indicate the class is a final class.

    Added in version 3.1.

  :single-line-parameter-list: (no value)

    See `py:class:single-line-parameter-list`.

    Added in version 7.1.

  :single-line-type-parameter-list: (no value)

    See `py:class:single-line-type-parameter-list`.

    Added in version 7.1.

.. py:class:: name
.. py:class:: name(parameters)
.. py:class:: name[type parameters](parameters)

  Describes a class. The signature can optionally include type parameters (see PEP 695) or parentheses with parameters which will be shown as the constructor arguments. See also Python Signatures.

  Methods and attributes belonging to the class should be placed in this directive’s body. If they are placed outside, the supplied name should contain the class name so that cross-references still work. Example:

      .. py:class:: Foo

         .. py:method:: quux()

      -- or --

      .. py:class:: Bar

      .. py:method:: Bar.quux()

  The first way is the preferred one.

  options

  :abstract: (no value)

    Indicate that the class is an abstract base class. This produces the following output:

    abstract class Cheese

      A cheesy representation.

    Added in version 8.2.

  :canonical: (full qualified name including module name)

    Describe the location where the object is defined if the object is imported from other modules

    Added in version 4.0.

  :final: (no value)

    Indicate the class is a final class.

    Added in version 3.1.

  :single-line-parameter-list: (no value)

    Ensures that the class constructor’s arguments will be emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

    Added in version 7.1.

  :single-line-type-parameter-list: (no value)

    Ensure that the class type parameters are emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

.. py:attribute:: name

  Describes an object data attribute. The description should include information about the type of the data to be expected and whether it may be changed directly. Type aliases should be documented with `py:type`.

  options

  :type: type of the attribute (text)

    This will be parsed as a Python expression for cross-referencing the type annotation. As such, the argument to `:type:` should be a valid annotation expression.

    Caution

    The valid syntax for the `:type:` directive option differs from the syntax for the `:type:` info field. The `:type:` directive option does not understand reStructuredText markup or the `or` or `of` keywords, meaning unions must use `|` and sequences must use square brackets, and roles such as `:ref:`...`` cannot be used.

    Added in version 2.4.

  :value: initial value of the attribute (text)

    Added in version 2.4.

  :canonical: (full qualified name including module name)

    Describe the location where the object is defined if the object is imported from other modules

    Added in version 4.0.

.. py:property:: name

  Describes an object property.

  Added in version 4.0.

  options

  :abstract: (no value)
  :abstractmethod: (no value)

    Indicate the property is abstract. This produces the following output:

    abstract property Cheese.amount_in_stock

      Cheese levels at the National Cheese Emporium.

    Changed in version 8.2: The `:abstract:` alias is also supported.

  :classmethod: (no value)

    Indicate the property is a classmethod.

    Added in version 4.2.

  :type: type of the property (text)

    This will be parsed as a Python expression for cross-referencing the type annotation. As such, the argument to `:type:` should be a valid annotation expression.

    Caution

    The valid syntax for the `:type:` directive option differs from the syntax for the `:type:` info field. The `:type:` directive option does not understand reStructuredText markup or the `or` or `of` keywords, meaning unions must use `|` and sequences must use square brackets, and roles such as `:ref:`...`` cannot be used.

.. py:type:: name

  Describe a type alias.

  The type that the alias represents should be described with the `canonical` option. This directive supports an optional description body.

  For example:

      .. py:type:: UInt64

         Represent a 64-bit positive integer.

  will be rendered as follows:

  type UInt64

    Represent a 64-bit positive integer.

  options

  :canonical: (text)

    The canonical type represented by this alias, for example:

        .. py:type:: StrPattern
           :canonical: str | re.Pattern[str]

           Represent a regular expression or a compiled pattern.

    This is rendered as:

    type StrPattern = str | re.Pattern[str]

      Represent a regular expression or a compiled pattern.

  Added in version 7.4.

.. py:method:: name(parameters)
.. py:method:: name[type parameters](parameters)

  Describes an object method. The parameters should not include the `self` parameter. The description should include similar information to that described for `function`. See also Python Signatures and Info field lists.

  options

  :abstract: (no value)
  :abstractmethod: (no value)

    Indicate the method is an abstract method. This produces the following output:

    abstractmethod Cheese.order_more_stock()

      Order more cheese (we’re fresh out!).

    Added in version 2.1.

    Changed in version 8.2: The `:abstract:` alias is also supported.

  :async: (no value)

    Indicate the method is an async method.

    Added in version 2.1.

  :canonical: (full qualified name including module name)

    Describe the location where the object is defined if the object is imported from other modules

    Added in version 4.0.

  :classmethod: (no value)

    Indicate the method is a class method.

    Added in version 2.1.

  :final: (no value)

    Indicate the method is a final method.

    Added in version 3.1.

  :single-line-parameter-list: (no value)

    Ensures that the method’s arguments will be emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

    Added in version 7.1.

  :single-line-type-parameter-list: (no value)

    Ensure that the method’s type parameters are emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

    Added in version 7.2.

  :staticmethod: (no value)

    Indicate the method is a static method.

    Added in version 2.1.

.. py:staticmethod:: name(parameters)
.. py:staticmethod:: name[type parameters](parameters)

  Like `py:method`, but indicates that the method is a static method.

  Added in version 0.4.

.. py:classmethod:: name(parameters)
.. py:classmethod:: name[type parameters](parameters)

  Like `py:method`, but indicates that the method is a class method.

  Added in version 0.6.

.. py:decorator:: name
.. py:decorator:: name(parameters)
.. py:decorator:: name[type parameters](parameters)

  Describes a decorator function. The signature should represent the usage as a decorator. For example, given the functions

      def removename(func):
          func.__name__ = ''
          return func

      def setnewname(name):
          def decorator(func):
              func.__name__ = name
              return func
          return decorator

  the descriptions should look like this:

      .. py:decorator:: removename

         Remove name of the decorated function.

      .. py:decorator:: setnewname(name)

         Set name of the decorated function to *name*.

  (as opposed to `.. py:decorator:: removename(func)`.)

  Refer to a decorator function using the `py:deco` role.

  :single-line-parameter-list: (no value)

    Ensures that the decorator’s arguments will be emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

    Added in version 7.1.

  :single-line-type-parameter-list: (no value)

    Ensure that the decorator’s type parameters are emitted on a single logical line, overriding `python_maximum_signature_line_length` and `maximum_signature_line_length`.

    Added in version 7.2.

.. py:decoratormethod:: name
.. py:decoratormethod:: name(signature)
.. py:decoratormethod:: name[type parameters](signature)

  Same as `py:decorator`, but for decorators that are methods.

  Refer to a decorator method using the `py:deco` role.

## Python Signatures

Signatures of functions, methods and class constructors can be given like they would be written in Python. This can include default values, positional-only or keyword-only parameters, type annotations, and type parameters. For example:

    .. py:function:: compile(source: str, filename: Path, symbol: str = 'file') -> ast.AST

compile(source: str, filename: Path, symbol: str = 'file') → ast.AST

For functions with optional parameters that don’t have default values (typically functions implemented in C extension modules without keyword argument support), you can list multiple versions of the same signature in a single directive:

compile(source)
compile(source, filename)
compile(source, filename, symbol)

Another approach is to use square brackets to specify the optional parts. When using square brackets, it is customary to place the opening bracket before the comma (`[,`).

compile(source[, filename[, symbol]])

Python 3.12 introduced type parameters, which are type variables declared directly within the class or function definition:

    class AnimalList[AnimalT](list[AnimalT]):
        ...

    def add[T](a: T, b: T) -> T:
        return a + b

The corresponding reStructuredText markup would be:

    .. py:class:: AnimalList[AnimalT]

    .. py:function:: add[T](a: T, b: T) -> T

See also

PEP 695 and PEP 696, for details and the full specification.

## Info field lists

Added in version 0.4.

Changed in version 3.0: meta fields are added.

Inside Python object description directives, reStructuredText field lists with these fields are recognized and formatted nicely:

- `param`, `parameter`, `arg`, `argument`, `key`, `keyword`: Description of a parameter.

- `type`: Type of a parameter. Creates a link if possible.

- `raises`, `raise`, `except`, `exception`: That (and when) a specific exception is raised.

- `var`, `ivar`, `cvar`: Description of a variable.

- `vartype`: Type of a variable. Creates a link if possible.

- `returns`, `return`: Description of the return value.

- `rtype`: Return type. Creates a link if possible.

- `meta`: Add metadata to description of the python object. The metadata will not be shown on output document. For example, `:meta private:` indicates the python object is private member. It is used in `sphinx.ext.autodoc` for filtering members.

Note

In current release, all `var`, `ivar` and `cvar` are represented as “Variable”. There is no difference at all.

The field names must consist of one of these keywords and an argument (except for `returns` and `rtype`, which do not need an argument). This is best explained by an example:

    .. py:function:: send_message(sender, recipient, message_body, [priority=1])

       Send a message to a recipient

       :param str sender: The person sending the message
       :param str recipient: The recipient of the message
       :param str message_body: The body of the message
       :param priority: The priority of the message, can be a number 1-5
       :type priority: int or None
       :return: the message id
       :rtype: int
       :raises ValueError: if the message_body exceeds 160 characters
       :raises TypeError: if the message_body is not a basestring

This will render like this:

send_message(sender, recipient, message_body[, priority=1])

  Send a message to a recipient

  Parameters:

    - sender (str) – The person sending the message

    - recipient (str) – The recipient of the message

    - message_body (str) – The body of the message

    - priority (int or None) – The priority of the message, can be a number 1-5

  Returns:

    the message id

  Return type:

    int

  Raises:

    - ValueError – if the message_body exceeds 160 characters

    - TypeError – if the message_body is not a basestring

It is also possible to combine parameter type and description, if the type is a single word, like this:

    :param int priority: The priority of the message, can be a number 1-5

Added in version 1.5.

Container types such as lists and dictionaries can be linked automatically using the following syntax:

    :type priorities: list(int)
    :type priorities: list[int]
    :type mapping: dict(str, int)
    :type mapping: dict[str, int]
    :type point: tuple(float, float)
    :type point: tuple[float, float]

Multiple types in a type field will be linked automatically if separated by either the vertical bar (`|`) or the word “or”:

    :type an_arg: int or None
    :vartype a_var: str or int
    :rtype: float or str

    :type an_arg: int | None
    :vartype a_var: str | int
    :rtype: float | str

## Cross-referencing Python objects

The following roles refer to objects in modules and are possibly hyperlinked if a matching identifier is found:

:py:mod:

  Reference a module; a dotted name may be used. This should also be used for package names.

:py:func:

  Reference a Python function; dotted names may be used. The role text needs not include trailing parentheses to enhance readability; they will be added automatically by Sphinx if the `add_function_parentheses` config value is `True` (the default).

:py:deco:

  Reference a Python decorator; dotted names may be used. The rendered output will be prepended with an at-sign (`@`), for example: `:py:deco:`removename`` produces `@removename`.

:py:data:

  Reference a module-level variable.

:py:const:

  Reference a “defined” constant. This may be a Python variable that is not intended to be changed.

:py:class:

  Reference a class; a dotted name may be used.

:py:meth:

  Reference a method of an object. The role text can include the type name and the method name; if it occurs within the description of a type, the type name can be omitted. A dotted name may be used.

:py:attr:

  Reference a data attribute of an object.

  Note

  The role is also able to refer to property.

:py:type:

  Reference a type alias.

:py:exc:

  Reference an exception. A dotted name may be used.

:py:obj:

  Reference an object of unspecified type. Useful e.g. as the `default_role`.

  Added in version 0.4.

### Target specification

The target can be specified as a fully qualified name (e.g. `:py:meth:`my_module.MyClass.my_method``) or any shortened version (e.g. `:py:meth:`MyClass.my_method`` or `:py:meth:`my_method``). See target resolution for details on the resolution of shortened names.

Cross-referencing modifiers can be applied. In short:

- You may supply an explicit title and reference target: `:py:mod:`mathematical functions <math>`` will refer to the `math` module, but the link text will be “mathematical functions”.

- If you prefix the content with an exclamation mark (`!`), no reference/hyperlink will be created.

- If you prefix the content with `~`, the link text will only be the last component of the target. For example, `:py:meth:`~queue.Queue.get`` will refer to `queue.Queue.get` but only display `get` as the link text.

### Target resolution

A given link target name is resolved to an object using the following strategy:

Names in these roles are searched first without any further qualification, then with the current module name prepended, then with the current module and class name (if any) prepended.

If you prefix the name with a dot (`.`), this order is reversed. For example, in the documentation of Python’s `codecs` module, `:py:func:`open`` always refers to the built-in function, while `:py:func:`.open`` refers to `codecs.open()`.

A similar heuristic is used to determine whether the name is an attribute of the currently documented class.

Also, if the name is prefixed with a dot, and no exact match is found, the target is taken as a suffix and all object names with that suffix are searched. For example, `:py:meth:`.TarFile.close`` references the `tarfile.TarFile.close()` function, even if the current module is not `tarfile`. Since this can get ambiguous, if there is more than one possible match, you will get a warning from Sphinx.

Note that you can combine the `~` and `.` prefixes: `:py:meth:`~.TarFile.close`` will reference the `tarfile.TarFile.close()` method, but the visible link caption will only be `close()`.