# Style Guide¶

The Python documentation should follow the Apple Publications Style Guide wherever possible. This particular style guide was selected mostly because it seems reasonable and is easy to get online.

Topics which are not covered in the Apple’s style guide will be discussed in this document.

All reST files use an indentation of 3 spaces. The maximum line length is 80 characters for normal text, but tables, deeply indented code samples and long links may extend beyond that.

Make generous use of blank lines where applicable; they help grouping 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.

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.
Unicode
The name of a character set and matching encoding. This is always written capitalized.
Unix
The name of the operating system developed at AT&T Bell Labs in the early 1970s.