The Python language has a substantial body of documentation, much of it contributed by various authors. The markup used for the Python documentation is reStructuredText, developed by the docutils project, amended by custom directives and using a toolset named Sphinx to post-process the HTML output.
This document describes the style guide for our documentation as well as the custom reStructuredText markup introduced by Sphinx to support Python documentation and how it should be used.
The documentation in HTML, PDF or EPUB format is generated from text files written using the :ref:`reStructuredText format <markup>` and contained in the :ref:`CPython Git repository <setup>`.
Note
If you're interested in contributing to Python's documentation, there's no need to write reStructuredText if you're not so inclined; plain text contributions are more than welcome as well. Send an e-mail to [email protected] or open an issue on the :ref:`tracker <reporting-bugs>`.
Python's documentation has long been considered to be good for a free programming language. There are a number of reasons for this, the most important being the early commitment of Python's creator, Guido van Rossum, to providing documentation on the language and its libraries, and the continuing involvement of the user community in providing assistance for creating and maintaining documentation.
The involvement of the community takes many forms, from authoring to bug reports to just plain complaining when the documentation could be more complete or easier to use.
This document is aimed at authors and potential authors of documentation for Python. More specifically, it is for people contributing to the standard documentation and developing additional documents using the same tools as the standard documents. This guide will be less useful for authors using the Python documentation tools for topics other than Python, and less useful still for authors not using the tools at all.
If your interest is in contributing to the Python documentation, but you don't have the time or inclination to learn reStructuredText and the markup structures documented here, there's a welcoming place for you among the Python contributors as well. Any time you feel that you can clarify existing documentation or provide documentation that's missing, the existing documentation team will gladly work with you to integrate your text, dealing with the markup for you. Please don't let the material in this document stand between the documentation and your desire to help out!
All reST files use an indentation of 3 spaces; no tabs are allowed. The maximum line length is 80 characters for normal text, but tables, deeply indented code samples and long links may extend beyond that. Code example bodies should use normal Python 4-space indentation.
Make generous use of blank lines where applicable; they help group things together.
A sentence-ending period may be followed by one or two spaces; while reST ignores the second space, it is customarily put in by some users, for example to aid Emacs' auto-fill mode.
Footnotes are generally discouraged, though they may be used when they are the best way to present specific information. When a footnote reference is added at the end of the sentence, it should follow the sentence-ending punctuation. The reST markup should appear something like this:
This sentence has a footnote reference. [#]_ This is the next sentence.Footnotes should be gathered at the end of a file, or if the file is very long, at the end of a section. The docutils will automatically create backlinks to the footnote reference.
Footnotes may appear in the middle of sentences where appropriate.
Sentence case
Sentence case is a set of capitalization rules used in English sentences: the first word is always capitalized and other words are only capitalized if there is a specific rule requiring it.
In the Python documentation, the use of sentence case in section titles is preferable, but consistency within a unit is more important than following this rule. If you add a section to a chapter where most sections are in title case, you can either convert all titles to sentence case or use the dominant style in the new section title.
Sentences that start with a word for which specific rules require starting it with a lower case letter should be avoided.
Note
Sections that describe a library module often have titles in the form of "modulename --- Short description of the module." In this case, the description should be capitalized as a stand-alone sentence.
Many special names are used in the Python documentation, including the names of operating systems, programming languages, standards bodies, and the like. Most of these entities are not assigned any special markup, but the preferred spellings are given here to aid authors in maintaining the consistency of presentation in the Python documentation.
Other terms and words deserve special mention as well; these conventions should be used to ensure consistency throughout the documentation:
- CPU
- For "central processing unit." Many style guides say this should be spelled out on the first use (and if you must use it, do so!). For the Python documentation, this abbreviation should be avoided since there's no reasonable way to predict which occurrence will be the first seen by the reader. It is better to use the word "processor" instead.
- POSIX
- The name assigned to a particular group of standards. This is always uppercase.
- Python
- The name of our favorite programming language is always capitalized.
- reST
- For "reStructuredText," an easy to read, plaintext markup syntax used to produce Python documentation. When spelled out, it is always one word and both forms start with a lower case 'r'.
- Unicode
- The name of a character coding system. This is always written capitalized.
- Unix
- The name of the operating system developed at AT&T Bell Labs in the early 1970s.
The documentation focuses on affirmatively stating what the language does and how to use it effectively.
Except for certain security or segfault risks, the docs should avoid wording along the lines of "feature x is dangerous" or "experts only". These kinds of value judgments belong in external blogs and wikis, not in the core documentation.
Bad example (creating worry in the mind of a reader):
Warning: failing to explicitly close a file could result in lost data or excessive resource consumption. Never rely on reference counting to automatically close a file.
Good example (establishing confident knowledge in the effective use of the language):
A best practice for using files is use a try/finally pair to explicitly close a file after it is used. Alternatively, using a with-statement can achieve the same effect. This assures that files are flushed and file descriptor resources are released in a timely manner.
More documentation is not necessarily better documentation. Err on the side of being succinct.
It is an unfortunate fact that making documentation longer can be an impediment to understanding and can result in even more ways to misread or misinterpret the text. Long descriptions full of corner cases and caveats can create the impression that a function is more complex or harder to use than it actually is.
Some modules provided with Python are inherently exposed to security issues (e.g. shell injection vulnerabilities) due to the purpose of the module (e.g. :mod:`ssl`). Littering the documentation of these modules with red warning boxes for problems that are due to the task at hand, rather than specifically to Python's support for that task, doesn't make for a good reading experience.
Instead, these security concerns should be gathered into a dedicated
"Security Considerations" section within the module's documentation, and
cross-referenced from the documentation of affected interfaces with a note
similar to "Please refer to the :ref:`security-considerations` section
for important information on how to avoid common mistakes.".
Similarly, if there is a common error that affects many interfaces in a module (e.g. OS level pipe buffers filling up and stalling child processes), these can be documented in a "Common Errors" section and cross-referenced rather than repeated for every affected interface.
Short code examples can be a useful adjunct to understanding. Readers can often grasp a simple example more quickly than they can digest a formal description in prose.
People learn faster with concrete, motivating examples that match the context of a typical use case. For instance, the :meth:`str.rpartition` method is better demonstrated with an example splitting the domain from a URL than it would be with an example of removing the last word from a line of Monty Python dialog.
The ellipsis for the :py:data:`sys.ps2` secondary interpreter prompt should only be used sparingly, where it is necessary to clearly differentiate between input lines and output lines. Besides contributing visual clutter, it makes it difficult for readers to cut-and-paste examples so they can experiment with variations.
Giving pure Python code equivalents (or approximate equivalents) can be a useful adjunct to a prose description. A documenter should carefully weigh whether the code equivalent adds value.
A good example is the code equivalent for :func:`all`. The short 4-line code equivalent is easily digested; it re-emphasizes the early-out behavior; and it clarifies the handling of the corner-case where the iterable is empty. In addition, it serves as a model for people wanting to implement a commonly requested alternative where :func:`all` would return the specific object evaluating to False whenever the function terminates early.
A more questionable example is the code for :func:`itertools.groupby`. Its code equivalent borders on being too complex to be a quick aid to understanding. Despite its complexity, the code equivalent was kept because it serves as a model to alternative implementations and because the operation of the "grouper" is more easily shown in code than in English prose.
An example of when not to use a code equivalent is for the :func:`oct` function. The exact steps in converting a number to octal doesn't add value for a user trying to learn what the function does.
The tone of the tutorial (and all the docs) needs to be respectful of the reader's intelligence. Don't presume that the readers are stupid. Lay out the relevant information, show motivating use cases, provide glossary links, and do your best to connect-the-dots, but don't talk down to them or waste their time.
The tutorial is meant for newcomers, many of whom will be using the tutorial to evaluate the language as a whole. The experience needs to be positive and not leave the reader with worries that something bad will happen if they make a misstep. The tutorial serves as guide for intelligent and curious readers, saving details for the how-to guides and other sources.
Be careful accepting requests for documentation changes from the rare but vocal category of reader who is looking for vindication for one of their programming errors ("I made a mistake, therefore the docs must be wrong ..."). Typically, the documentation wasn't consulted until after the error was made. It is unfortunate, but typically no documentation edit would have saved the user from making false assumptions about the language ("I was surprised by ...").
This section is a brief introduction to reStructuredText (reST) concepts and syntax, intended to provide authors with enough information to author documents productively. Since reST was designed to be a simple, unobtrusive markup language, this will not take too long.
.. seealso::
The authoritative `reStructuredText User
Documentation <http://docutils.sourceforge.net/rst.html>`_.
The paragraph is the most basic block in a reST document. Paragraphs are simply chunks of text separated by one or more blank lines. As in Python, indentation is significant in reST, so all lines of the same paragraph must be left-aligned to the same level of indentation.
The standard reST inline markup is quite simple: use
- one asterisk:
*text*for emphasis (italics), - two asterisks:
**text**for strong emphasis (boldface), and - backquotes:
``text``for code samples.
If asterisks or backquotes appear in running text and could be confused with inline markup delimiters, they have to be escaped with a backslash.
Be aware of some restrictions of this markup:
- it may not be nested,
- content may not start or end with whitespace:
* text*is wrong, - it must be separated from surrounding text by non-word characters. Use a
backslash escaped space to work around that:
thisis\ *one*\ word.
These restrictions may be lifted in future versions of the docutils.
reST also allows for custom "interpreted text roles"', which signify that the
enclosed text should be interpreted in a specific way. Sphinx uses this to
provide semantic markup and cross-referencing of identifiers, as described in
the appropriate section. The general syntax is :rolename:`content`.
List markup is natural: just place an asterisk at the start of a paragraph and
indent properly. The same goes for numbered lists; they can also be
automatically numbered using a # sign:
* This is a bulleted list.
* It has two items, the second
item uses two lines.
1. This is a numbered list.
2. It has two items too.
#. This is a numbered list.
#. It has two items too.Nested lists are possible, but be aware that they must be separated from the parent list items by blank lines:
* this is
* a list
* with a nested list
* and some subitems
* and here the parent list continuesDefinition lists are created as follows:
term (up to a line of text)
Definition of the term, which must be indented
and can even consist of multiple paragraphs
next term
Description.Paragraphs are quoted by just indenting them more than the surrounding paragraphs.
Literal code blocks are introduced by ending a paragraph with the special marker
::. The literal block must be indented:
This is a normal text paragraph. The next paragraph is a code sample::
It is not processed in any way, except
that the indentation is removed.
It can span multiple lines.
This is a normal text paragraph again.The handling of the :: marker is smart:
- If it occurs as a paragraph of its own, that paragraph is completely left out of the document.
- If it is preceded by whitespace, the marker is removed.
- If it is preceded by non-whitespace, the marker is replaced by a single colon.
That way, the second sentence in the above example's first paragraph would be rendered as "The next paragraph is a code sample:".
Use `Link text <http://target>`_ for inline web links. If the link text
should be the web address, you don't need special markup at all, the parser
finds links and mail addresses in ordinary text.
Internal linking is done via a special reST role, see the section on specific markup, :ref:`doc-ref-role`.
Section headers are created by underlining (and optionally overlining) the section title with a punctuation character, at least as long as the text:
=================
This is a heading
=================Normally, there are no heading levels assigned to certain characters as the structure is determined from the succession of headings. However, for the Python documentation, here is a suggested convention:
#with overline, for parts*with overline, for chapters=, for sections-, for subsections^, for subsubsections", for paragraphs
"Explicit markup" is used in reST for most constructs that need special handling, such as footnotes, specially-highlighted paragraphs, comments, and generic directives.
An explicit markup block begins with a line starting with .. followed by
whitespace and is terminated by the next paragraph at the same level of
indentation. (There needs to be a blank line between explicit markup and normal
paragraphs. This may all sound a bit complicated, but it is intuitive enough
when you write it.)
A directive is a generic block of explicit markup. Besides roles, it is one of the extension mechanisms of reST, and Sphinx makes heavy use of it.
Basically, a directive consists of a name, arguments, options and content. (Keep this terminology in mind, it is used in the next chapter describing custom directives.) Looking at this example,
.. function:: foo(x)
foo(y, z)
:bar: no
Return a line of text input from the user.function is the directive name. It is given two arguments here, the
remainder of the first line and the second line, as well as one option bar
(as you can see, options are given in the lines immediately following the
arguments and indicated by the colons).
The directive content follows after a blank line and is indented relative to the directive start.
For footnotes, use [#]_ to mark the footnote location, and add the footnote
body at the bottom of the document after a "Footnotes" rubric heading, like so:
Lorem ipsum [#]_ dolor sit amet ... [#]_
.. rubric:: Footnotes
.. [#] Text of the first footnote.
.. [#] Text of the second footnote.You can also explicitly number the footnotes for better context.
Every explicit markup block which isn't a valid markup construct (like the footnotes above) is regarded as a comment.
Since the easiest way to include special characters like em dashes or copyright signs in reST is to directly write them as Unicode characters, one has to specify an encoding:
All Python documentation source files must be in UTF-8 encoding, and the HTML documents written from them will be in that encoding as well.
There are some problems one commonly runs into while authoring reST documents:
- Separation of inline markup: As said above, inline markup spans must be separated from the surrounding text by non-word characters, you have to use an escaped space to get around that.
Sphinx adds a lot of new directives and interpreted text roles to standard reST markup. This section contains the reference material for these facilities. Documentation for "standard" reST constructs is not included here, though they are used in the Python documentation.
Note
This is just an overview of Sphinx' extended markup capabilities; full coverage can be found in its own documentation.
.. describe:: sectionauthor
Identifies the author of the current section. The argument should include
the author's name such that it can be used for presentation (though it isn't)
and email address. The domain name portion of the address should be lower
case. Example::
.. sectionauthor:: Guido van Rossum <[email protected]>
Currently, this markup isn't reflected in the output in any way, but it helps
keep track of contributions.
The markup described in this section is used to provide information about a module being documented. Each module should be documented in its own file. Normally this markup appears after the title heading of that file; a typical file might start like this:
:mod:`parrot` -- Dead parrot access
===================================
.. module:: parrot
:platform: Unix, Windows
:synopsis: Analyze and reanimate dead parrots.
.. moduleauthor:: Eric Cleese <[email protected]>
.. moduleauthor:: John Idle <[email protected]>As you can see, the module-specific markup consists of two directives, the
module directive and the moduleauthor directive.
.. describe:: module
This directive marks the beginning of the description of a module, package,
or submodule. The name should be fully qualified (i.e. including the
package name for submodules).
The ``platform`` option, if present, is a comma-separated list of the
platforms on 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.
The ``synopsis`` option should consist of one sentence describing the
module's purpose -- it is currently only used in the Global Module Index.
The ``deprecated`` option can be given (with no value) to mark a module as
deprecated; it will be designated as such in various locations then.
.. describe:: moduleauthor
The ``moduleauthor`` directive, which can appear multiple times, names the
authors of the module code, just like ``sectionauthor`` names the author(s)
of a piece of documentation. It too does not result in any output currently.
Note
It is important to make the section title of a module-describing file meaningful since that value will be inserted in the table-of-contents trees in overview files.
There are a number of directives used to describe specific features provided by
modules. Each directive requires one or more signatures to provide basic
information about what is being described, and the content should be the
description. The basic version makes entries in the general index; if no index
entry is desired, you can give the directive option flag :noindex:. The
following example shows all of the features of this directive type:
.. function:: spam(eggs)
ham(eggs)
:noindex:
Spam or ham the foo.The signatures of object methods or data attributes should not include the class name, but be nested in a class directive. The generated files will reflect this nesting, and the target identifiers (for HTML output) will use both the class and method name, to enable consistent cross-references. If you describe methods belonging to an abstract protocol such as context managers, use a class directive with a (pseudo-)type name too to make the index entries more informative.
The directives are:
.. describe:: c:function
Describes a C function. The signature should be given as in C, e.g.::
.. c:function:: PyObject* PyType_GenericAlloc(PyTypeObject *type, Py_ssize_t nitems)
This is also used to describe function-like preprocessor macros. The names
of the arguments should be given so they may be used in the description.
Note that you don't have to backslash-escape asterisks in the signature,
as it is not parsed by the reST inliner.
.. describe:: c:member
Describes a C struct member. Example signature::
.. c:member:: PyObject* PyTypeObject.tp_bases
The text of the description should include the range of values allowed, how
the value should be interpreted, and whether the value can be changed.
References to structure members in text should use the ``member`` role.
.. describe:: c:macro
Describes a "simple" C macro. Simple macros are macros which are used
for code expansion, but which do not take arguments so cannot be described as
functions. This is not to be used for simple constant definitions. Examples
of its use in the Python documentation include :c:macro:`PyObject_HEAD` and
:c:macro:`Py_BEGIN_ALLOW_THREADS`.
.. describe:: c:type
Describes a C type. The signature should just be the type name.
.. describe:: c:var
Describes a global C variable. The signature should include the type, such
as::
.. cvar:: PyObject* PyClass_Type
.. describe:: data
Describes global data in a module, including both variables and values used
as "defined constants." Class and object attributes are not documented
using this directive.
.. describe:: exception
Describes an exception class. The signature can, but need not include
parentheses with constructor arguments.
.. describe:: function
Describes a module-level function. The signature should include the
parameters, enclosing optional parameters in brackets. Default values can be
given if it enhances clarity. For example::
.. function:: repeat([repeat=3[, number=1000000]])
Object methods are not documented using this directive. Bound object methods
placed in the module namespace as part of the public interface of the module
are documented using this, as they are equivalent to normal functions for
most purposes.
The description should include information about the parameters required and
how they are used (especially whether mutable objects passed as parameters
are modified), side effects, and possible exceptions. A small example may be
provided.
.. describe:: coroutinefunction
Describes a module-level coroutine. The description should include similar
information to that described for ``function``.
.. describe:: decorator
Describes a decorator function. The signature should *not* represent the
signature of the actual function, but the usage as a decorator. For example,
given the functions
.. code-block:: python
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::
.. decorator:: removename
Remove name of the decorated function.
.. decorator:: setnewname(name)
Set name of the decorated function to *name*.
There is no ``deco`` role to link to a decorator that is marked up with
this directive; rather, use the ``:func:`` role.
.. describe:: class
Describes a class. The signature can include parentheses with parameters
which will be shown as the constructor arguments.
.. describe:: attribute
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. This directive should be nested in a class directive,
like in this example::
.. class:: Spam
Description of the class.
.. attribute:: ham
Description of the attribute.
If is also possible to document an attribute outside of a class directive,
for example if the documentation for different attributes and methods is
split in multiple sections. The class name should then be included
explicitly::
.. attribute:: Spam.eggs
.. describe:: method
Describes an object method. The parameters should not include the ``self``
parameter. The description should include similar information to that
described for ``function``. This directive should be nested in a class
directive, like in the example above.
.. describe:: coroutinemethod
Describes an object coroutine method. The parameters should not include the
``self`` parameter. The description should include similar information to
that described for ``function``. This directive should be nested in a
``class`` directive.
.. describe:: decoratormethod
Same as ``decorator``, but for decorators that are methods.
Refer to a decorator method using the ``:meth:`` role.
.. describe:: staticmethod
Describes an object static method. The description should include similar
information to that described for ``function``. This directive should be
nested in a ``class`` directive.
.. describe:: classmethod
Describes an object class method. The parameters should not include the
``cls`` parameter. The description should include similar information to
that described for ``function``. This directive should be nested in a
``class`` directive.
.. describe:: abstractmethod
Describes an object abstract method. The description should include similar
information to that described for ``function``. This directive should be
nested in a ``class`` directive.
.. describe:: opcode
Describes a Python :term:`bytecode` instruction.
.. describe:: cmdoption
Describes a Python command line option or switch. Option argument names
should be enclosed in angle brackets. Example::
.. cmdoption:: -m <module>
Run a module as a script.
.. describe:: envvar
Describes an environment variable that Python uses or defines.
There is also a generic version of these directives:
.. describe:: describe
This directive produces the same formatting as the specific ones explained
above but does not create index entries or cross-referencing targets. It is
used, for example, to describe the directives in this document. Example::
.. describe:: opcode
Describes a Python bytecode instruction.
Examples of Python source code or interactive sessions are represented using
standard reST literal blocks. They are started by a :: at the end of the
preceding paragraph and delimited by indentation.
Representing an interactive session requires including the prompts and output along with the Python code. No special markup is required for interactive sessions. After the last line of input or output presented, there should not be an "unused" primary prompt; this is an example of what not to do:
>>> 1 + 1
2
>>>Syntax highlighting is handled in a smart way:
There is a "highlighting language" for each source file. By default, this is
'python'as the majority of files will have to highlight Python snippets.Within Python highlighting mode, interactive sessions are recognized automatically and highlighted appropriately.
The highlighting language can be changed using the
highlightdirective, used as follows:.. highlight:: c
This language is used until the next
highlightdirective is encountered.The
code-blockdirective can be used to specify the highlight language of a single code block, e.g.:.. code-block:: c #include <stdio.h> void main() { printf("Hello world!\n"); }
The values normally used for the highlighting language are:
python(the default)crestnone(no highlighting)
If highlighting with the current language fails, the block is not highlighted in any way.
Longer displays of verbatim text may be included by storing the example text in
an external file containing only plain text. The file may be included using the
literalinclude directive. [1] For example, to include the Python source
file :file:`example.py`, use:
.. literalinclude:: example.pyThe file name is relative to the current file's path. Documentation-specific
include files should be placed in the Doc/includes subdirectory.
As said before, Sphinx uses interpreted text roles to insert semantic markup in documents.
Names of local variables, such as function/method arguments, are an exception,
they should be marked simply with *var*.
For all other roles, you have to write :rolename:`content`.
There are some additional facilities that make cross-referencing roles more versatile:
You may supply an explicit title and reference target, like in reST direct hyperlinks:
:role:`title <target>`will refer to target, but the link text will be title.If you prefix the content with
!, no reference/hyperlink will be created.For the Python object roles, if you prefix the content with
~, the link text will only be the last component of the target. For example,:meth:`~Queue.Queue.get`will refer toQueue.Queue.getbut only displaygetas the link text.In HTML output, the link's
titleattribute (that is e.g. shown as a tool-tip on mouse-hover) will always be the full target name.
The following roles refer to objects in modules and are possibly hyperlinked if a matching identifier is found:
.. describe:: mod
The name of a module; a dotted name may be used. This should also be used
for package names.
.. describe:: func
The name of a Python function; dotted names may be used. The role text
should not include trailing parentheses to enhance readability. The
parentheses are stripped when searching for identifiers.
.. describe:: data
The name of a module-level variable or constant.
.. describe:: const
The name of a "defined" constant. This may be a C-language ``#define``
or a Python variable that is not intended to be changed.
.. describe:: class
A class name; a dotted name may be used.
.. describe:: meth
The name of a method of an object. The role text should include the type
name and the method name. A dotted name may be used.
.. describe:: attr
The name of a data attribute of an object.
.. describe:: exc
The name of an exception. A dotted name may be used.
The name enclosed in this markup can include a module name and/or a class name.
For example, :func:`filter` could refer to a function named filter in
the current module, or the built-in function of that name. In contrast,
:func:`foo.filter` clearly refers to the filter function in the foo
module.
Normally, 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 the
:mod:`codecs` module, :func:`open` always refers to the built-in function,
while :func:`.open` refers to :func:`codecs.open`.
A similar heuristic is used to determine whether the name is an attribute of the currently documented class.
The following roles create cross-references to C-language constructs if they are defined in the API documentation:
.. describe:: c:data
The name of a C-language variable.
.. describe:: c:func
The name of a C-language function. Should include trailing parentheses.
.. describe:: c:macro
The name of a "simple" C macro, as defined above.
.. describe:: c:type
The name of a C-language type.
.. describe:: c:member
The name of a C type member, as defined above.
The following roles do not refer to objects, but can create cross-references or internal links:
.. describe:: envvar
An environment variable. Index entries are generated.
.. describe:: keyword
The name of a Python keyword. Using this role will generate a link to the
documentation of the keyword. ``True``, ``False`` and ``None`` do not use
this role, but simple code markup (````True````), given that they're
fundamental to the language and should be known to any programmer.
.. describe:: option
A command-line option of Python. The leading hyphen(s) must be included.
If a matching ``cmdoption`` directive exists, it is linked to. For options
of other programs or scripts, use simple ````code```` markup.
.. describe:: token
The name of a grammar token (used in the reference manual to create links
between production displays).
The following role creates a cross-reference to the term in the glossary:
.. describe:: term
Reference to a term in the glossary. The glossary is created using the
``glossary`` directive containing a definition list with terms and
definitions. It does not have to be in the same file as the ``term``
markup, in fact, by default the Python docs have one global glossary
in the ``glossary.rst`` file.
If you use a term that's not explained in a glossary, you'll get a warning
during build.
The following roles don't do anything special except formatting the text in a different style:
.. describe:: command
The name of an OS-level command, such as ``rm``.
.. describe:: dfn
Mark the defining instance of a term in the text. (No index entries are
generated.)
.. describe:: file
The name of a file or directory. Within the contents, you can use curly
braces to indicate a "variable" part, for example::
``spam`` is installed in :file:`/usr/lib/python2.{x}/site-packages` ...
In the built documentation, the ``x`` will be displayed differently to
indicate that it is to be replaced by the Python minor version.
.. describe:: guilabel
Labels presented as part of an interactive user interface should be marked
using ``guilabel``. This includes labels from text-based interfaces such as
those created using :mod:`curses` or other text-based libraries. Any label
used in the interface should be marked with this role, including button
labels, window titles, field names, menu and menu selection names, and even
values in selection lists.
.. describe:: kbd
Mark a sequence of keystrokes. What form the key sequence takes may depend
on platform- or application-specific conventions. When there are no relevant
conventions, the names of modifier keys should be spelled out, to improve
accessibility for new users and non-native speakers. For example, an
*xemacs* key sequence may be marked like ``:kbd:`C-x C-f```, but without
reference to a specific application or platform, the same sequence should be
marked as ``:kbd:`Control-x Control-f```.
.. describe:: mailheader
The name of an RFC 822-style mail header. This markup does not imply that
the header is being used in an email message, but can be used to refer to any
header of the same "style." This is also used for headers defined by the
various MIME specifications. The header name should be entered in the same
way it would normally be found in practice, with the camel-casing conventions
being preferred where there is more than one common usage. For example:
``:mailheader:`Content-Type```.
.. describe:: makevar
The name of a :command:`make` variable.
.. describe:: manpage
A reference to a Unix manual page including the section,
e.g. ``:manpage:`ls(1)```.
.. describe:: menuselection
Menu selections should be marked using the ``menuselection`` role. This is
used to mark a complete sequence of menu selections, including selecting
submenus and choosing a specific operation, or any subsequence of such a
sequence. The names of individual selections should be separated by
``-->``.
For example, to mark the selection "Start > Programs", use this markup::
:menuselection:`Start --> Programs`
When including a selection that includes some trailing indicator, such as the
ellipsis some operating systems use to indicate that the command opens a
dialog, the indicator should be omitted from the selection name.
.. describe:: mimetype
The name of a MIME type, or a component of a MIME type (the major or minor
portion, taken alone).
.. describe:: newsgroup
The name of a Usenet newsgroup.
.. describe:: program
The name of an executable program. This may differ from the file name for
the executable for some platforms. In particular, the ``.exe`` (or other)
extension should be omitted for Windows programs.
.. describe:: regexp
A regular expression. Quotes should not be included.
.. describe:: samp
A piece of literal text, such as code. Within the contents, you can use
curly braces to indicate a "variable" part, as in ``:file:``.
If you don't need the "variable part" indication, use the standard
````code```` instead.
The following roles generate external links:
.. describe:: pep
A reference to a Python Enhancement Proposal. This generates appropriate
index entries. The text "PEP *number*\ " is generated; in the HTML output,
this text is a hyperlink to an online copy of the specified PEP. Such
hyperlinks should not be a substitute for properly documenting the
language in the manuals.
.. describe:: rfc
A reference to an Internet Request for Comments. This generates appropriate
index entries. The text "RFC *number*\ " is generated; in the HTML output,
this text is a hyperlink to an online copy of the specified RFC.
Note that there are no special roles for including hyperlinks as you can use the standard reST markup for that purpose.
To support cross-referencing to arbitrary sections in the documentation, the standard reST labels are "abused" a bit: Every label must precede a section title; and every label name must be unique throughout the entire documentation source.
You can then reference to these sections using the :ref:`label-name` role.
Example:
.. _my-reference-label:
Section to cross-reference
--------------------------
This is the text of the section.
It refers to the section itself, see :ref:`my-reference-label`.The :ref: invocation is replaced with the section title.
Alternatively, you can reference any label (not just section titles)
if you provide the link text :ref:`link text <reference-label>`.
These directives create short paragraphs and can be used inside information units as well as normal text:
.. describe:: note
An especially important bit of information about an API that a user should be
aware of when using whatever bit of API the note pertains to. The content of
the directive should be written in complete sentences and include all
appropriate punctuation.
Example::
.. note::
This function is not suitable for sending spam e-mails.
.. describe:: warning
An important bit of information about an API that a user should be aware of
when using whatever bit of API the warning pertains to. The content of the
directive should be written in complete sentences and include all appropriate
punctuation. In the interest of not scaring users away from pages filled
with warnings, this directive should only be chosen over ``note`` for
information regarding the possibility of crashes, data loss, or security
implications.
.. describe:: versionadded
This directive documents the version of Python which added the described
feature, or a part of it, to the library or C API. When this applies to an
entire module, it should be placed at the top of the module section before
any prose.
The first argument must be given and is the version in question. The second
argument is optional and can be used to describe the details of the feature.
Example::
.. versionadded:: 3.5
.. describe:: versionchanged
Similar to ``versionadded``, but describes when and what changed in the named
feature in some way (new parameters, changed side effects, platform support,
etc.). This one *must* have the second argument (explanation of the change).
Example::
.. versionchanged:: 3.1
The *spam* parameter was added.
Note that there should be no blank line between the directive head and the
explanation; this is to make these blocks visually continuous in the markup.
.. describe:: deprecated
Indicates the version from which the described feature is deprecated.
There is one required argument: the version from which the feature is
deprecated.
Example::
.. deprecated:: 3.8
.. describe:: deprecated-removed
Like ``deprecated``, but it also indicates in which version the feature is
removed.
There are two required arguments: the version from which the feature is
deprecated, and the version in which the feature is removed.
Example::
.. deprecated-removed:: 3.8 4.0
.. describe:: impl-detail
This directive is used to mark CPython-specific information. Use either with
a block content or a single sentence as an argument, i.e. either ::
.. impl-detail::
This describes some implementation detail.
More explanation.
or ::
.. impl-detail:: This shortly mentions an implementation detail.
"\ **CPython implementation detail:**\ " is automatically prepended to the
content.
.. describe:: seealso
Many sections include a list of references to module documentation or
external documents. These lists are created using the ``seealso`` directive.
The ``seealso`` directive is typically placed in a section just before any
sub-sections. For the HTML output, it is shown boxed off from the main flow
of the text.
The content of the ``seealso`` directive should be a reST definition list.
Example::
.. seealso::
Module :mod:`zipfile`
Documentation of the :mod:`zipfile` standard module.
`GNU tar manual, Basic Tar Format <http://link>`_
Documentation for tar archive files, including GNU tar extensions.
.. describe:: rubric
This directive creates a paragraph heading that is not used to create a
table of contents node. It is currently used for the "Footnotes" caption.
.. describe:: centered
This directive creates a centered boldfaced paragraph. Use it as follows::
.. centered::
Paragraph contents.
Since reST does not have facilities to interconnect several documents, or split
documents into multiple output files, Sphinx uses a custom directive to add
relations between the single files the documentation is made of, as well as
tables of contents. The toctree directive is the central element.
.. describe:: toctree
This directive inserts a "TOC tree" at the current location, using the
individual TOCs (including "sub-TOC trees") of the files given in the
directive body. A numeric ``maxdepth`` option may be given to indicate the
depth of the tree; by default, all levels are included.
Consider this example (taken from the library reference index)::
.. toctree::
:maxdepth: 2
intro
strings
datatypes
numeric
(many more files listed here)
This accomplishes two things:
* Tables of contents from all those files are inserted, with a maximum depth
of two, that means one nested heading. ``toctree`` directives in those
files are also taken into account.
* Sphinx knows that the relative order of the files ``intro``,
``strings`` and so forth, and it knows that they are children of the
shown file, the library index. From this information it generates "next
chapter", "previous chapter" and "parent chapter" links.
In the end, all files included in the build process must occur in one
``toctree`` directive; Sphinx will emit a warning if it finds a file that is
not included, because that means that this file will not be reachable through
standard navigation.
The special file ``contents.rst`` at the root of the source directory is the
"root" of the TOC tree hierarchy; from it the "Contents" page is generated.
Sphinx automatically creates index entries from all information units (like functions, classes or attributes) like discussed before.
However, there is also an explicit directive available, to make the index more comprehensive and enable index entries in documents where information is not mainly contained in information units, such as the language reference.
The directive is index and contains one or more index entries. Each entry
consists of a type and a value, separated by a colon.
For example:
.. index::
single: execution; context
module: __main__
module: sys
triple: module; search; pathThis directive contains five entries, which will be converted to entries in the generated index which link to the exact location of the index statement (or, in case of offline media, the corresponding page number).
The possible entry types are:
- single
- Creates a single index entry. Can be made a subentry by separating the subentry text with a semicolon (this notation is also used below to describe what entries are created).
- pair
pair: loop; statementis a shortcut that creates two index entries, namelyloop; statementandstatement; loop.- triple
- Likewise,
triple: module; search; pathis a shortcut that creates three index entries, which aremodule; search path,search; path, moduleandpath; module search. - module, keyword, operator, object, exception, statement, builtin
- These all create two index entries. For example,
module: hashlibcreates the entriesmodule; hashlibandhashlib; module. The builtin entry type is slightly different in that "built-in function" is used in place of "builtin" when creating the two entries.
For index directives containing only "single" entries, there is a shorthand notation:
.. index:: BNF, grammar, syntax, notationThis creates four index entries.
Special markup is available for displaying the productions of a formal grammar. The markup is simple and does not attempt to model all aspects of BNF (or any derived forms), but provides enough to allow context-free grammars to be displayed in a way that causes uses of a symbol to be rendered as hyperlinks to the definition of the symbol. There is this directive:
.. describe:: productionlist
This directive is used to enclose a group of productions. Each production is
given on a single line and consists of a name, separated by a colon from the
following definition. If the definition spans multiple lines, each
continuation line must begin with a colon placed at the same column as in the
first line.
Blank lines are not allowed within ``productionlist`` directive arguments.
The definition can contain token names which are marked as interpreted text
(e.g. ``unaryneg ::= "-" `integer```) -- this generates cross-references
to the productions of these tokens.
Note that no further reST parsing is done in the production, so that you
don't have to escape ``*`` or ``|`` characters.
The following is an example taken from the Python Reference Manual:
.. productionlist::
try_stmt: try1_stmt | try2_stmt
try1_stmt: "try" ":" `suite`
: ("except" [`expression` ["," `target`]] ":" `suite`)+
: ["else" ":" `suite`]
: ["finally" ":" `suite`]
try2_stmt: "try" ":" `suite`
: "finally" ":" `suite`The documentation system provides three substitutions that are defined by default. They are set in the build configuration file :file:`conf.py`.
.. describe:: |release|
Replaced by the Python release the documentation refers to. This is the full
version string including alpha/beta/release candidate tags, e.g. ``2.5.2b3``.
.. describe:: |version|
Replaced by the Python version the documentation refers to. This consists
only of the major and minor version parts, e.g. ``2.5``, even for version
2.5.1.
.. describe:: |today|
Replaced by either today's date, or the date set in the build configuration
file. Normally has the format ``April 14, 2007``.
Footnotes
| [1] | There is a standard include directive, but it raises errors if the
file is not found. This one only emits a warning. |
The toolset used to build the docs is written in Python and is called Sphinx. Sphinx is maintained separately and is not included in this tree. Also needed are blurb, a tool to create :file:`Misc/NEWS` on demand; and python-docs-theme, the Sphinx theme for the Python documentation.
To build the documentation, follow the instructions from one of the sections below. You can view the documentation after building the HTML by pointing a browser at the file :file:`Doc/build/html/index.html`.
You are expected to have installed the latest stable version of
Sphinx and blurb on your system or in a virtualenv (which can be
created using make venv), so that the Makefile can find the
sphinx-build command. You can also specify the location of
sphinx-build with the SPHINXBUILD :command:`make` variable.
On Unix, run the following from the root of your :ref:`repository clone <checkout>` to build the output as HTML:
cd Doc
make venv
make htmlor alternatively make -C Doc/ venv html.
You can also use make help to see a list of targets supported by
:command:`make`. Note that make check is automatically run when
you submit a :doc:`pull request <pullrequest>`, so you should make
sure that it runs without errors.
On Windows, a :file:`make.bat` batchfile tries to emulate :command:`make` as closely as possible, but the venv target is not implemented, so you will probably want to make sure you are working in a virtual environment before proceeding, otherwise all dependencies will be automatically installed on your system.
When ready, run the following from the root of your :ref:`repository clone <checkout>` to build the output as HTML:
cd Doc
make htmlYou can also use make help to see a list of targets supported by
:file:`make.bat`.
See also :file:`Doc/README.rst` for more information.
Sometimes we directly want to execute the sphinx-build tool instead of through make (although the latter is still the preferred way). In this case, you can use the following command line from the Doc directory (make sure to install Sphinx, blurb and python-docs-theme packages from PyPI):
sphinx-build -b<builder> . build/<builder>where <builder> is one of html, text, latex, or htmlhelp (for explanations
see the make targets above).
Python documentation translations are governed by the PEP 545, they are built by docsbuild-scripts and hosted on docs.python.org. There are several documentation translations already in production, other are work in progress:
| Language | Contact | Links |
|---|---|---|
| Arabic (ar) | Abdur-Rahmaan Janhangeer | github |
| Bengali as spoken in India (bn_IN) | Kushal Das | github |
| French (fr) | Julien Palard (mdk) | github doc |
| Hindi as spoken in India (hi_IN) | github | |
| Hungarian (hu) | Tamás Bajusz (gbtami) | |
| Italian (it) | ||
| Japanese (ja) | Kinebuchi Tomohiko (cocoatomo) | |
| Korean (ko) | ||
| Lithuanian (lt) | ||
| Polish (pl) | ||
| Portuguese (pt) | Gustavo Toffo | |
| Portuguese as spoken in Brasil (pt-br) | Marco Rougeth | |
| Russian (ru) | ||
| Simplified Chinese (zh-cn) | Shengjing Zhu | |
| Spanish (es) | Raul Cumplido | |
| Traditional Chinese (zh-tw) | 廖偉涵 Adrian Liaw | |
| Turkish (tr) | github |
First subscribe to the doc-sig mailing list, and introduce yourself and the translation you're starting.
Then you can bootstrap your new translation by using our cookiecutter.
The important steps looks like this:
- Create the github repo (anywhere), with the right hierarchy (using the cookiecutter).
- Gather people to help you translating, you can't do it alone.
- You can use any tool to translate, as long as you can synchronize with git. Some are using Transifex, some are using only github, or you can choose another way, it's up to you.
- Ensure we updated this page to reflect your work and progress, either via a PR, or by asking on the doc-sig mailing list.
- When
tutorial/,library/stdtypesandlibrary/functionsare complete, ask on doc-sig for your language to be added in the language picker on docs.python.org.
Here are the essential points of PEP 545:
- Each translation is assigned an appropriate lowercased language tag,
with an optional region subtag, joined with a dash, like
pt-brorfr. - Each translation is under CC0 and marked as so in the README (as in the cookiecutter).
- Translations files are hosted on
https://github.com/python/python-docs-{LANGUAGE_TAG}(not mandatory to start a translation, but mandatory to land ondocs.python.org). - Translations having completed
tutorial/,library/stdtypesandlibrary/functionsare hosted onhttps://docs.python.org/{LANGUAGE_TAG}/{VERSION_TAG}/.
Discussions about translations occur on the doc-sig mailing list,
and there's a freenode IRC channel, #python-doc.
Consensus is to work on current stable, you can then propagate your translation from a branch to another using pomerge.
Here's what's we're using:
- pomerge to propagate translation from a files to others.
- pospell to check for typo in po files.
- powrap to rewrap the
.pofiles before committing, this helps keeping git diffs short. - potodo to list what needs to be translated.
There is no election, each country have to sort this out. Here are some suggestions.
- Coordinator requests are to be public on doc-sig mailing list.
- If the given language have a native core dev, the core dev have its word on the choice.
- Anyone who wants to become coordinator for its native language, and shows motivation by translating and building a community, will be named coordinator.
- In case of concurrency between two persons, no one will sort this out for you. It is up to you two to organize a local election or whatever needed to sort this out.
- In case a coordinator become inactive or unreachable for a long period of time, someone else can ask for a takeover on doc-sig.
Ask on doc-sig, or better, make a PR on the devguide.
Just ask for help on the doc-sig mailing list and our python-fu, git-fu and bash-fu combined will help you create an appropriate repository. If you use a tool like transifex don’t worry. Keeping them in sync is not that hard.
No, inside the github.com/python organization we’ll all have the
exact same hierarchy so bots will be able to build all of our
translations. So you may have to convert from one hierarchy to another.
Ask for help on the doc-sig mailing list if you’re not sure on how to do
it.
As for every project, we have a branch per version. We store po
files in the root of the repository using the gettext_compact=0
style.