Showing code examples¶
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 done with Pygments (if it’s installed) and handled in a smart way:
There is a “highlighting language” for each source file. Per default, this is
'python'as the majority of files will have to highlight Python snippets, but the doc-wide default can be set with the
Within Python highlighting mode, interactive sessions are recognized automatically and highlighted appropriately. Normal Python code is only highlighted if it is parseable (so you can use Python as the default, but interspersed snippets of shell commands or other code blocks will not be highlighted as Python).
The highlighting language can be changed using the
highlightdirective, used as follows:
.. highlight:: c
This language is used until the next
highlightdirective is encountered.
For documents that have to show snippets in different languages, there’s also a
code-blockdirective that is given the highlighting language directly:
Use it like this:
.. code-block:: ruby Some Ruby code.
The directive’s alias name
sourcecodeworks as well.
The valid values for the highlighting language are:
If highlighting with the selected language fails (i.e. Pygments emits an “Error” token), the block is not highlighted in any way.
If installed, Pygments can generate line numbers for code blocks. For
automatically-highlighted blocks (those started by
::), line numbers must be
switched on in a
highlight directive, with the
.. highlight:: python :linenothreshold: 5
This will produce line numbers for all code blocks longer than five lines.
code-block blocks, a
linenos flag option can be given to
switch on line numbers for the individual block:
.. code-block:: ruby :linenos: Some more Ruby code.
The first line number can be selected with the
lineno-start option. If
linenos is automatically activated as well.
10 Some more Ruby code, with line numbering starting at 10.
emphasize-lines option can be given to have Pygments
emphasize particular lines:
.. code-block:: python :emphasize-lines: 3,5 def some_function(): interesting = False print 'This line is highlighted.' print 'This one is not...' print '...but this one is.'
Changed in version 1.1:
emphasize-lines has been added.
Changed in version 1.3:
lineno-start has been added.
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
literalincludedirective.  For example, to include the Python source file
.. literalinclude:: example.py
The file name is usually relative to the current file’s path. However, if it is absolute (starting with
/), it is relative to the top source directory.
Tabs in the input are expanded if you give a
tab-widthoption with the desired tab width.
code-block, the directive supports the
linenosflag option to switch on line numbers, the
lineno-startoption to select the first line number, the
emphasize-linesoption to emphasize particular lines, and a
languageoption to select a language different from the current file’s standard language. Example with options:
.. literalinclude:: example.rb :language: ruby :emphasize-lines: 12,15-18 :linenos:
Include files are assumed to be encoded in the
source_encoding. If the file has a different encoding, you can specify it with the
.. literalinclude:: example.py :encoding: latin-1
The directive also supports including only parts of the file. If it is a Python module, you can select a class, function or method to include using the
.. literalinclude:: example.py :pyobject: Timer.start
This would only include the code lines belonging to the
start()method in the
Timerclass within the file.
Alternately, you can specify exactly which lines to include by giving a
.. literalinclude:: example.py :lines: 1,3,5-10,20-
This includes the lines 1, 3, 5 to 10 and lines 20 to the last line.
Another way to control which part of the file is included is to use the
end-beforeoptions (or only one of them). If
start-afteris given as a string option, only lines that follow the first line containing that string are included. If
end-beforeis given as a string option, only lines that precede the first lines containing that string are included.
When specifying particular parts of a file to display, it can be useful to display exactly which lines are being presented. This can be done using the
You can prepend and/or append a line to the included code, using the
appendoption, respectively. This is useful e.g. for highlighting PHP code that doesn’t include the
If you want to show the diff of the code, you can specify the old file by giving a
.. literalinclude:: example.py :diff: example.py.orig
This shows the diff between example.py and example.py.orig with unified diff format.
New in version 0.4.3: The
New in version 0.6: The
end-beforeoptions, as well as support for absolute filenames.
New in version 1.0: The
appendoptions, as well as
New in version 1.3: The
Showing a file name¶
New in version 1.3.
caption option can be given to show that name before the code block. For
.. code-block:: python :caption: this.py print 'Explicit is better than implicit.'
literalinclude also supports the
caption option, with the
additional feature that if you leave the value empty, the shown filename will be
exactly the one given as an argument.
New in version 1.3.
dedent option can be given to strip a precedence characters from the code
block. For example:
.. literalinclude:: example.rb :language: ruby :dedent: 4 :lines: 10-15
code-block also supports the
|||There is a standard |