default_values¶

Sphinx extension to show default values in documentation.

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Overview¶

This extension shows the default values in autodoc-formatted docstrings.

The default behaviour of autodoc is to turn this:

def namedlist(name: str = "NamedList") -> Callable:
    """
    A factory function to return a custom list subclass with a name.

    :param name: The name of the list.

    :return:
    """

into this:

domdf_python_tools.bases.namedlist(name='NamedList')

A factory function to return a custom list subclass with a name.

Parameters

name (str) – The name of the list.

Return type

Callable

With default_values enabled, the documentation will now look like this:

domdf_python_tools.bases.namedlist(name='NamedList')

A factory function to return a custom list subclass with a name.

Parameters

name (str) – The name of the list. Default 'NamedList'.

Return type

Callable

Default values are taken from the function/class signature. They can be overridden using the default option in the docstring. The default value can be suppressed using the no-default option.

No default value is shown if the argument does not have a default value.

The formatting of the default value can be customised using the default_description_format option in conf.py. By default this is 'Default %s'.

Contents¶

Installation¶

python3 -m pip install default_values --user

First add the required channels

conda config --add channels https://conda.anaconda.org/conda-forge
conda config --add channels https://conda.anaconda.org/domdfcoding

Then install

conda install default_values

python3 -m pip install git+https://github.com/sphinx-toolbox/default_values@master --user

Enable default_values by adding the following to the extensions variable in your conf.py:

extensions = [
    ...
    'sphinx.ext.autodoc',
    'sphinxcontrib.default_values',
    ]

For more information see https://www.sphinx-doc.org/en/master/usage/extensions#third-party-extensions .

Configuration¶

default_description_format¶: Type: str

Required: False

Default: Default %s

The format string for the default value.

Fields¶

These fields can be used in docstrings for classes, functions, methods etc., alongside other fields such as :param:.

:default <name>: value¶

Overrides the default value for <name>.

The value must be formatted how you would like it to be displayed in Sphinx. This can be useful when the default value in the signature is None and the true default value is assigned in the function body, such as for a mutable default argument.

Example:

:param name: The name of the list.
:default name: :py:obj:`True`

domdf_python_tools.bases.namedlist(name='NamedList')

A factory function to return a custom list subclass with a name.

Parameters: name (str) – The name of the list. Default True.
Return type: Callable

:no-default <name>: value¶

Suppresses display of the default value for <name>.

This allows for default values to be suppressed on a per-argument basis.

Example:

:param name: The name of the list.
:no-default name:

domdf_python_tools.bases.namedlist(name='NamedList')

A factory function to return a custom list subclass with a name.

Parameters: name (str) – The name of the list.
Return type: Callable

Public API¶

Sphinx extension to show default values in documentation.

Data:

`default_regex`	Regular expression to match default values declared in docstrings.
`no_default_regex`	Regular expression to match fields in docstrings to suppress default values.

Functions:

`format_default_value`(value)	Format the value as a string.
`get_arguments`(obj)	Returns a dictionary mapping argument names to parameters/arguments for a function.
`get_class_defaults`(obj)	Obtains the default values for the arguments of a class.
`get_function_defaults`(obj)	Obtains the default values for the arguments of a function.
`process_default_format`(app)	Prepare the formatting of the default value.
`process_docstring`(app, what, name, obj, …)	Add default values to the docstring.
`setup`(app)	Setup `sphinxcontrib.default_values`.

default_regex¶

Type: Pattern

Regular expression to match default values declared in docstrings.

Changed in version 0.5.0: Change to be case insensitive.

Pattern	`^:(default)[ ]`

format_default_value(value)[source]¶

Format the value as a string.

New in version 0.5.0.

Parameters: value (Any)
Return type: Optional[str]

get_arguments(obj)[source]¶

Returns a dictionary mapping argument names to parameters/arguments for a function.

Parameters: obj (Callable) – A function (can be the __init__ method of a class).
Return type: Mapping[str, Parameter]

get_class_defaults(obj)[source]¶

Obtains the default values for the arguments of a class.

Parameters: obj (Type) – The class.
Return type: Iterator[Tuple[str, Any]]
Returns: An iterator of 2-element tuples comprising the argument name and its default value.

get_function_defaults(obj)[source]¶

Obtains the default values for the arguments of a function.

Parameters: obj (Callable) – The function.
Return type: Iterator[Tuple[str, Any]]
Returns: An iterator of 2-element tuples comprising the argument name and its default value.

no_default_regex¶

Type: Pattern

Regular expression to match fields in docstrings to suppress default values.

Changed in version 0.5.0: Change to be case insensitive.

Pattern	`^:(no[-_]default)[ ]`

process_default_format(app)[source]¶

Prepare the formatting of the default value.

Parameters: app (Sphinx)

process_docstring(app, what, name, obj, options, lines)[source]¶

Add default values to the docstring.

Parameters

app (Sphinx) – The Sphinx app.
what (str)
name (str) – The name of the object being documented.
obj (Any) – The object being documented.
options (Dict[str, Any]) – Mapping of autodoc options to values.
lines (List[str]) – List of strings representing the current contents of the docstring.

setup(app)[source]¶

Setup sphinxcontrib.default_values.

Parameters: app (Sphinx)
Return type: Dict[str, Any]

Demo¶

demo(a, b=0.0, c='', d=' ', e='hello world', f=(), g=Decimal('12.34'), h=1234, i=None, j=None, k=None, l='', m='\t', n=...)[source]¶

Parameters

a (Any) – No default.
b (float) – A float. Default 0.0.
c (str) – An empty string. Default ''.
d (str) – A space (or a smiley face?). Default '␣'.
e (str) – A string. Default 'hello world'.
f (Tuple) – A Tuple. Default ().
g (Decimal) – A Decimal. Default Decimal('12.34').
h (int) – An int. Default 1234.
i (Optional[List[str]]) – Default None. Default None.
j (Optional[List[str]]) – Overridden default. Default [].
k (Optional[List[str]]) – Suppressed default.
l (str) – This is a really long description. It spans multiple lines. The quick brown fox jumps over the lazy dog. The default value should be added at the end regardless. Default ''.
m (str) – Tab. Default '\t'.
n (Any) – This argument’s default value is undefined.

The description for d lacked a fullstop at the end, but one was added automatically.

The default value of n was Ellipsis, but it wasn’t shown.

The above example was created from the following Python code:

# noqa: D100

# stdlib
from decimal import Decimal  # pragma: no cover
from typing import Any, List, Optional, Tuple  # pragma: no cover

__all__ = ["demo"]  # pragma: no cover


def demo(
        a: Any,
        b: float = 0.0,
        c: str = '',
        d: str = ' ',
        e: str = "hello world",
        f: Tuple = (),
        g: Decimal = Decimal("12.34"),
        h: int = 1234,
        i: Optional[List[str]] = None,
        j: Optional[List[str]] = None,
        k: Optional[List[str]] = None,
        l: str = '',
        m: str = '\t',
        n: Any = ...,
        ):  # pragma: no cover
    """

    :param a: No default.
    :param b: A float.
    :param c: An empty string.
    :param d: A space (or a smiley face?)
    :param e: A string.
    :param f: A Tuple.
    :param g: A Decimal.
    :param h: An int.
    :param i: Default None.
    :param j: Overridden default.
    :default j: ``[]``
    :param k: Suppressed default.
    :no-default k:
    :param l: This is a really long description.
        It spans multiple lines.
        The quick brown fox jumps over the lazy dog.
        The default value should be added at the end regardless.
    :param m: Tab.
    :param n: This argument's default value is undefined.

    The description for ``d`` lacked a fullstop at the end, but one was added automatically.

    The default value of ``n`` was :py:obj:`Ellipsis`, but it wasn't shown.
    """

The PEP 484 type hints were added by sphinx-autodoc-typehints.

Downloading source code¶

The default_values source code is available on GitHub, and can be accessed from the following URL: https://github.com/sphinx-toolbox/default_values

If you have git installed, you can clone the repository with the following command:

git clone https://github.com/sphinx-toolbox/default_values

Cloning into 'default_values'...
remote: Enumerating objects: 47, done.
remote: Counting objects: 100% (47/47), done.
remote: Compressing objects: 100% (41/41), done.
remote: Total 173 (delta 16), reused 17 (delta 6), pack-reused 126
Receiving objects: 100% (173/173), 126.56 KiB | 678.00 KiB/s, done.
Resolving deltas: 100% (66/66), done.

Alternatively, the code can be downloaded in a ‘zip’ file by clicking:

Clone or download –> Download Zip

Downloading a ‘zip’ file of the source code¶

Building from source¶

The recommended way to build default_values is to use tox:

tox -e build

The source and wheel distributions will be in the directory dist.

If you wish, you may also use pep517.build or another PEP 517-compatible build tool.

View the Function Index or browse the Source Code.

Browse the GitHub Repository