PEP: 12 Title: Sample reStructuredText PEP Template Author: David
Goodger <goodger@python.org>, Barry Warsaw <barry@python.org>, Brett
Cannon <brett@python.org> Status: Active Type: Process Created:
05-Aug-2002 Post-History: 30-Aug-2002

Note

For those who have written a PEP before, there is a template (which is
included as a file in the PEPs repository).

Abstract

This PEP provides a boilerplate or sample template for creating your own
reStructuredText PEPs. In conjunction with the content guidelines in PEP
1, this should make it easy for you to conform your own PEPs to the
format outlined below.

Note: if you are reading this PEP via the web, you should first grab the
text (reStructuredText) source of this PEP in order to complete the
steps below. DO NOT USE THE HTML FILE AS YOUR TEMPLATE!

The source for this (or any) PEP can be found in the PEPs repository, as
well as via a link at the bottom of each PEP.

Rationale

If you intend to submit a PEP, you MUST use this template, in
conjunction with the format guidelines below, to ensure that your PEP
submission won't get automatically rejected because of form.

ReStructuredText provides PEP authors with useful functionality and
expressivity, while maintaining easy readability in the source text. The
processed HTML form makes the functionality accessible to readers: live
hyperlinks, styled text, tables, images, and automatic tables of
contents, among other advantages.

How to Use This Template

To use this template you must first decide whether your PEP is going to
be an Informational or Standards Track PEP. Most PEPs are Standards
Track because they propose a new feature for the Python language or
standard library. When in doubt, read PEP 1 for details, or open a
tracker issue on the PEPs repo to ask for assistance.

Once you've decided which type of PEP yours is going to be, follow the
directions below.

-   Make a copy of this file (the .rst file, not the HTML!) and perform
    the following edits. Name the new file pep-{NNNN}.rst, using the
    next available number (not used by a published or in-PR PEP).

-   Replace the "PEP: 12" header with "PEP: NNNN", matching the file
    name. Note that the file name should be padded with zeros (eg
    pep-0012.rst), but the header should not (PEP: 12).

-   Change the Title header to the title of your PEP.

-   Change the Author header to include your name, and optionally your
    email address. Be sure to follow the format carefully: your name
    must appear first, and it must not be contained in parentheses. Your
    email address may appear second (or it can be omitted) and if it
    appears, it must appear in angle brackets. It is okay to obfuscate
    your email address.

-   If none of the authors are Python core developers, include a Sponsor
    header with the name of the core developer sponsoring your PEP.

-   Add the direct URL of the PEP's canonical discussion thread (on e.g.
    Python-Dev, Discourse, etc) under the Discussions-To header. If the
    thread will be created after the PEP is submitted as an official
    draft, it is okay to just list the venue name initially, but
    remember to update the PEP with the URL as soon as the PEP is
    successfully merged to the PEPs repository and you create the
    corresponding discussion thread. See PEP 1 <1#discussing-a-pep> for
    more details.

-   Change the Status header to "Draft".

-   For Standards Track PEPs, change the Type header to "Standards
    Track".

-   For Informational PEPs, change the Type header to "Informational".

-   For Standards Track PEPs, if your feature depends on the acceptance
    of some other currently in-development PEP, add a Requires header
    right after the Type header. The value should be the PEP number of
    the PEP yours depends on. Don't add this header if your dependent
    feature is described in a Final PEP.

-   Change the Created header to today's date. Be sure to follow the
    format carefully: it must be in dd-mmm-yyyy format, where the mmm is
    the 3 English letter month abbreviation, i.e. one of Jan, Feb, Mar,
    Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec.

-   For Standards Track PEPs, after the Created header, add a
    Python-Version header and set the value to the next planned version
    of Python, i.e. the one your new feature will hopefully make its
    first appearance in. Do not use an alpha or beta release designation
    here. Thus, if the last version of Python was 2.2 alpha 1 and you're
    hoping to get your new feature into Python 2.2, set the header to:

        Python-Version: 2.2

-   Add a Topic header if the PEP belongs under one shown at the
    topic-index. Most PEPs don't.

-   Leave Post-History alone for now; you'll add dates and corresponding
    links to this header each time you post your PEP to the designated
    discussion forum (and update the Discussions-To header with said
    link, as above). For each thread, use the date (in the dd-mmm-yyy
    format) as the linked text, and insert the URLs inline as anonymous
    reST hyperlinks, with commas in between each posting.

    If you posted threads for your PEP on August 14, 2001 and September
    3, 2001, the Post-History header would look like, e.g.:

        Post-History: `14-Aug-2001 <https://www.example.com/thread_1>`__,
                      `03-Sept-2001 <https://www.example.com/thread_2>`__

    You should add the new dates/links here as soon as you post a new
    discussion thread.

-   Add a Replaces header if your PEP obsoletes an earlier PEP. The
    value of this header is the number of the PEP that your new PEP is
    replacing. Only add this header if the older PEP is in "final" form,
    i.e. is either Accepted, Final, or Rejected. You aren't replacing an
    older open PEP if you're submitting a competing idea.

-   Now write your Abstract, Rationale, and other content for your PEP,
    replacing all this gobbledygook with your own text. Be sure to
    adhere to the format guidelines below, specifically on the
    prohibition of tab characters and the indentation requirements. See
    "Suggested Sections" below for a template of sections to include.

-   Update your Footnotes section, listing any footnotes and non-inline
    link targets referenced by the text.

-   Run ./build.py to ensure the PEP is rendered without errors, and
    check that the output in build/pep-{NNNN}.html looks as you intend.

-   Create a pull request against the PEPs repository.

For reference, here are all of the possible header fields (everything in
brackets should either be replaced or have the field removed if it has a
leading * marking it as optional and it does not apply to your PEP):

    PEP: [NNN]
    Title: [...]
    Author: [Full Name <email at example.com>]
    Sponsor: *[Full Name <email at example.com>]
    PEP-Delegate:
    Discussions-To: [URL]
    Status: Draft
    Type: [Standards Track | Informational | Process]
    Topic: *[Governance | Packaging | Release | Typing]
    Requires: *[NNN]
    Created: [DD-MMM-YYYY]
    Python-Version: *[M.N]
    Post-History: [`DD-MMM-YYYY <URL>`__]
    Replaces: *[NNN]
    Superseded-By: *[NNN]
    Resolution:

ReStructuredText PEP Formatting Requirements

The following is a PEP-specific summary of reStructuredText syntax. For
the sake of simplicity and brevity, much detail is omitted. For more
detail, see Resources below. Literal blocks (in which no markup
processing is done) are used for examples throughout, to illustrate the
plaintext markup.

General

Lines should usually not extend past column 79, excepting URLs and
similar circumstances. Tab characters must never appear in the document
at all.

Section Headings

PEP headings must begin in column zero and the initial letter of each
word must be capitalized as in book titles. Acronyms should be in all
capitals. Section titles must be adorned with an underline, a single
repeated punctuation character, which begins in column zero and must
extend at least as far as the right edge of the title text (4 characters
minimum). First-level section titles are underlined with "=" (equals
signs), second-level section titles with "-" (hyphens), and third-level
section titles with "'" (single quotes or apostrophes). For example:

    First-Level Title
    =================

    Second-Level Title
    ------------------

    Third-Level Title
    '''''''''''''''''

If there are more than three levels of sections in your PEP, you may
insert overline/underline-adorned titles for the first and second levels
as follows:

    ============================
    First-Level Title (optional)
    ============================

    -----------------------------
    Second-Level Title (optional)
    -----------------------------

    Third-Level Title
    =================

    Fourth-Level Title
    ------------------

    Fifth-Level Title
    '''''''''''''''''

You shouldn't have more than five levels of sections in your PEP. If you
do, you should consider rewriting it.

You must use two blank lines between the last line of a section's body
and the next section heading. If a subsection heading immediately
follows a section heading, a single blank line in-between is sufficient.

The body of each section is not normally indented, although some
constructs do use indentation, as described below. Blank lines are used
to separate constructs.

Paragraphs

Paragraphs are left-aligned text blocks separated by blank lines.
Paragraphs are not indented unless they are part of an indented
construct (such as a block quote or a list item).

Inline Markup

Portions of text within paragraphs and other text blocks may be styled.
For example:

    Text may be marked as *emphasized* (single asterisk markup,
    typically shown in italics) or **strongly emphasized** (double
    asterisks, typically boldface).  ``Inline literals`` (using double
    backquotes) are typically rendered in a monospaced typeface.  No
    further markup recognition is done within the double backquotes,
    so they're safe for any kind of code snippets.

Block Quotes

Block quotes consist of indented body elements. For example:

    This is a paragraph.

        This is a block quote.

        A block quote may contain many paragraphs.

Block quotes are used to quote extended passages from other sources.
Block quotes may be nested inside other body elements. Use 4 spaces per
indent level.

Literal Blocks

Literal blocks are used for code samples and other preformatted text. To
indicate a literal block, preface the indented text block with "::" (two
colons), or use the .. code-block:: directive. Indent the text block by
4 spaces; the literal block continues until the end of the indentation.
For example:

    This is a typical paragraph.  A literal block follows.

    ::

        for a in [5, 4, 3, 2, 1]:  # this is program code, shown as-is
            print(a)
        print("it's...")

"::" is also recognized at the end of any paragraph; if not immediately
preceded by whitespace, one colon will remain visible in the final
output:

    This is an example::

        Literal block

By default, literal blocks will be syntax-highlighted as Python code.
For specific blocks that contain code or data in other
languages/formats, use the .. code-block:: language directive,
substituting the "short name" of the appropriate Pygments lexer (or text
to disable highlighting) for language. For example:

    .. code-block:: rst

        An example of the ``rst`` lexer (i.e. *reStructuredText*).

For PEPs that predominantly contain literal blocks of a specific
language, use the .. highlight:: language directive with the appropriate
language at the top of the PEP body (below the headers and above the
Abstract). All literal blocks will then be treated as that language,
unless specified otherwise in the specific .. code-block. For example:

    .. highlight:: c

    Abstract
    ========

    Here's some C code::

        printf("Hello, World!\n");

Lists

Bullet list items begin with one of "-", "*", or "+" (hyphen, asterisk,
or plus sign), followed by whitespace and the list item body. List item
bodies must be left-aligned and indented relative to the bullet; the
text immediately after the bullet determines the indentation. For
example:

    This paragraph is followed by a list.

    * This is the first bullet list item.  The blank line above the
      first list item is required; blank lines between list items
      (such as below this paragraph) are optional.

    * This is the first paragraph in the second item in the list.

      This is the second paragraph in the second item in the list.
      The blank line above this paragraph is required.  The left edge
      of this paragraph lines up with the paragraph above, both
      indented relative to the bullet.

      - This is a sublist.  The bullet lines up with the left edge of
        the text blocks above.  A sublist is a new list so requires a
        blank line above and below.

    * This is the third item of the main list.

    This paragraph is not part of the list.

Enumerated (numbered) list items are similar, but use an enumerator
instead of a bullet. Enumerators are numbers (1, 2, 3, ...), letters (A,
B, C, ...; uppercase or lowercase), or Roman numerals (i, ii, iii, iv,
...; uppercase or lowercase), formatted with a period suffix ("1.",
"2."), parentheses ("(1)", "(2)"), or a right-parenthesis suffix ("1)",
"2)"). For example:

    1. As with bullet list items, the left edge of paragraphs must
       align.

    2. Each list item may contain multiple paragraphs, sublists, etc.

       This is the second paragraph of the second list item.

       a) Enumerated lists may be nested.
       b) Blank lines may be omitted between list items.

Definition lists are written like this:

    what
        Definition lists associate a term with a definition.

    how
        The term is a one-line phrase, and the definition is one
        or more paragraphs or body elements, indented relative to
        the term.

Tables

Simple tables are easy and compact:

    =====  =====  =======
      A      B    A and B
    =====  =====  =======
    False  False  False
    True   False  False
    False  True   False
    True   True   True
    =====  =====  =======

There must be at least two columns in a table (to differentiate from
section titles). Column spans use underlines of hyphens ("Inputs" spans
the first two columns):

    =====  =====  ======
       Inputs     Output
    ------------  ------
      A      B    A or B
    =====  =====  ======
    False  False  False
    True   False  True
    False  True   True
    True   True   True
    =====  =====  ======

Text in a first-column cell starts a new row. No text in the first
column indicates a continuation line; the rest of the cells may consist
of multiple lines. For example:

    =====  =========================
    col 1  col 2
    =====  =========================
    1      Second column of row 1.
    2      Second column of row 2.
           Second line of paragraph.
    3      - Second column of row 3.

           - Second item in bullet
             list (row 3, column 2).
    =====  =========================

Hyperlinks

When referencing an external web page in the body of a PEP, you should
include the title of the page or a suitable description in the text,
with either an inline hyperlink or a separate explicit target with the
URL. Do not include bare URLs in the body text of the PEP, and use HTTPS
links wherever available.

Hyperlink references use backquotes and a trailing underscore to mark up
the reference text; backquotes are optional if the reference text is a
single word. For example, to reference a hyperlink target named
Python website, you would write:

    In this paragraph, we refer to the `Python website`_.

If you intend to only reference a link once, and want to define it
inline with the text, insert the link into angle brackets (<>) after the
text you want to link, but before the closing backtick, with a space
between the text and the opening backtick. You should also use a
double-underscore after the closing backtick instead of a single one,
which makes it an anonymous reference to avoid conflicting with other
target names. For example:

    Visit the `website <https://www.python.org/>`__ for more.

If you want to use one link multiple places with different linked text,
or want to ensure you don't have to update your link target names when
changing the linked text, include the target name within angle brackets
following the text to link, with an underscore after the target name but
before the closing angle bracket (or the link will not work). For
example:

    For further examples, see the `documentation <pydocs_>`_.

An explicit target provides the URL. Put targets in the Footnotes
section at the end of the PEP, or immediately after the paragraph with
the reference. Hyperlink targets begin with two periods and a space (the
"explicit markup start"), followed by a leading underscore, the
reference text, a colon, and the URL.

    .. _Python web site: https://www.python.org/
    .. _pydocs: https://docs.python.org/

The reference text and the target text must match (although the match is
case-insensitive and ignores differences in whitespace). Note that the
underscore trails the reference text but precedes the target text. If
you think of the underscore as a right-pointing arrow, it points away
from the reference and toward the target.

Internal and PEP/RFC Links

The same mechanism as hyperlinks can be used for internal references.
Every unique section title implicitly defines an internal hyperlink
target. We can make a link to the Abstract section like this:

    Here is a hyperlink reference to the `Abstract`_ section.  The
    backquotes are optional since the reference text is a single word;
    we can also just write: Abstract_.

To refer to PEPs or RFCs, always use the :pep: and :rfc: roles, never
hardcoded URLs. For example:

    See PEP 1 for more information on how to write a PEP,
    and :pep:`the Hyperlink section of PEP 12 <12#hyperlinks>` for how to link.

This renders as:

  See PEP 1 for more information on how to write a PEP, and
  the Hyperlink section of PEP 12 <12#hyperlinks> for how to link.

PEP numbers in the text are never padded, and there is a space (not a
dash) between "PEP" or "RFC" and the number; the above roles will take
care of that for you.

Footnotes

Footnote references consist of a left square bracket, a label, a right
square bracket, and a trailing underscore. Instead of a number, use a
label of the form "#word", where "word" is a mnemonic consisting of
alphanumerics plus internal hyphens, underscores, and periods (no
whitespace or other characters are allowed). For example:

    Refer to The TeXbook [#TeXbook]_ for more information.

which renders as

  Refer to The TeXbook for more information.

Whitespace must precede the footnote reference. Leave a space between
the footnote reference and the preceding word.

Use footnotes for additional notes, explanations and caveats, as well as
for references to books and other sources not readily available online.
Native reST hyperlink targets or inline hyperlinks in the text should be
used in preference to footnotes for including URLs to online resources.

Footnotes begin with ".. " (the explicit markup start), followed by the
footnote marker (no underscores), followed by the footnote body. For
example:

    .. [#TeXbook] Donald Knuth's *The TeXbook*, pages 195 and 196.

which renders as

  

Footnotes and footnote references will be numbered automatically, and
the numbers will always match.

Images

If your PEP contains a diagram or other graphic, you may include it in
the processed output using the image directive:

    .. image:: diagram.png

Any browser-friendly graphics format is possible; PNG should be
preferred for graphics, JPEG for photos and GIF for animations.
Currently, SVG must be avoided due to compatibility issues with the PEP
build system.

For accessibility and readers of the source text, you should include a
description of the image and any key information contained within using
the :alt: option to the image directive:

    .. image:: dataflow.png
       :alt: Data flows from the input module, through the "black box"
             module, and finally into (and through) the output module.

Comments

A comment is an indented block of arbitrary text immediately following
an explicit markup start: two periods and whitespace. Leave the ".." on
a line by itself to ensure that the comment is not misinterpreted as
another explicit markup construct. Comments are not visible in the
processed document. For example:

    ..
       This section should be updated in the final PEP.
       Ensure the date is accurate.

Escaping Mechanism

reStructuredText uses backslashes ("\") to override the special meaning
given to markup characters and get the literal characters themselves. To
get a literal backslash, use an escaped backslash ("\\"). There are two
contexts in which backslashes have no special meaning: literal blocks
and inline literals (see Inline Markup above). In these contexts, no
markup recognition is done, and a single backslash represents a literal
backslash, without having to double up.

If you find that you need to use a backslash in your text, consider
using inline literals or a literal block instead.

Intersphinx

You can use Intersphinx references to other Sphinx sites, such as the
Python documentation packaging.python.org, and typing.readthedocs.io, to
easily cross-reference pages, sections and Python/C objects.

For example, to create a link pointing to a section of the typing docs,
you would write the following:

    :ref:`type expression <typing:type-expression>`

Canonical Documentation

As PEP 1 describes <1#pep-maintenance>, PEPs are considered historical
documents once marked Final, and their canonical
documentation/specification should be moved elsewhere. To indicate this,
use the canonical-doc directive or an appropriate subclass:

-   canonical-pypa-spec for packaging standards
-   canonical-typing-spec for typing standards

Add the directive between the headers and the first section of the PEP
(typically the Abstract) and pass as an argument an Intersphinx
reference of the canonical doc/spec (or if the target is not on a Sphinx
site, a reST hyperlink).

For example, to create a banner pointing to the python:sqlite3 docs, you
would write the following:

    .. canonical-doc:: :mod:`python:sqlite3`

which would generate the banner:

  python:sqlite3

Or for a PyPA spec, such as the packaging:core-metadata, you would use:

    .. canonical-pypa-spec:: :ref:`packaging:core-metadata`

which renders as:

  packaging:core-metadata

For a typing PEP that introduces no new runtime objects, you might use
something like the first one of these; for a typing PEP that introduces
a new object to the typing module at runtime, you might use the second:

    .. canonical-typing-spec:: :ref:`typing:packaging-typed-libraries`
    .. canonical-typing-spec:: :ref:`typing:literal-types` and
                               :py:data:`typing.Literal`

The two render as:

  typing:packaging-typed-libraries

  typing:literal-types and typing.Literal

The argument accepts arbitrary reST, so you can include multiple linked
docs/specs and name them whatever you like, and you can also include
directive content that will be inserted into the text. The following
advanced example:

    .. canonical-doc:: the :ref:`python:sqlite3-connection-objects` and :exc:`python:~sqlite3.DataError` docs

        Also, see the :ref:`Data Persistence docs <persistence>` for other examples.

would render as:

  the python:sqlite3-connection-objects and python:sqlite3.DataError
  docs

  Also, see the Data Persistence docs <persistence> for other examples.

Habits to Avoid

Many programmers who are familiar with TeX often write quotation marks
like this:

    `single-quoted' or ``double-quoted''

Backquotes are significant in reStructuredText, so this practice should
be avoided. For ordinary text, use ordinary 'single-quotes' or
"double-quotes". For inline literal text (see Inline Markup above), use
double-backquotes:

    ``literal text: in here, anything goes!``

Suggested Sections

Various sections are found to be common across PEPs and are outlined in
PEP 1. Those sections are provided here for convenience.

Resources

Many other constructs and variations are possible, both those supported
by basic Docutils and the extensions added by Sphinx.

A number of resources are available to learn more about them:

-   Sphinx ReStructuredText Primer, a gentle but fairly detailed
    introduction.
-   reStructuredText Markup Specification, the authoritative,
    comprehensive documentation of the basic reST syntax, directives,
    roles and more.
-   Sphinx Roles and Sphinx Directives, the extended constructs added by
    the Sphinx documentation system used to render the PEPs to HTML.

If you have questions or require assistance with writing a PEP that the
above resources don't address, ping @python/pep-editors on GitHub, open
an issue on the PEPs repository or reach out to a PEP editor directly.

Copyright

This document is placed in the public domain or under the
CC0-1.0-Universal license, whichever is more permissive.