An extension to Python-Markdown that adds a syntax for defining meta-data about
a document. The Meta-Data extension is inspired by and follows the syntax of
MultiMarkdown. Currently, this extension does not use the meta-data in any
way, but simply provides it as a Meta
attribute of a markdown instance for
use by other extensions or directly by your python code.
This extension has been a part of the Markdown library since 2.0.
Meta-data consists of a series of keywords and values defined at the beginning of a markdown document like this:
Title: My Document
Summary: A brief description of my document.
Authors: Waylan Limberg
John Doe
Date: October 2, 2007
blank-value:
base_url: http://example.com
This is the first paragraph of the document.
The keywords are case-insensitive and may consist of letters, numbers, underscores and dashes and must end with a colon. The values consist of anything following the colon on the line and may even be blank. If a line is indented 4 or more spaces, that line is assumed to be an additional line of the value for the previous keyword. A keyword may have as many lines as desired. The first blank line ends all meta-data for the document. Therefore, the first line of a document must not be blank. All meta-data is stripped from the document prior to any further processing by markdown.
The meta-data is made available as a python Dict in the Meta
attribute of an
instance of the Markdown class. For example, using the above document:
>>> md = markdown.Markdown(extensions = ['meta'])
>>> html = md.convert(text)
>>> # Meta-data has been stripped from output
>>> print html
<p>This is the first paragraph of the document.</p>
>>> # View meta-data
>>> print md.Meta
{
'title' : ['My Document'],
'summary' : ['A brief description of my document.'],
'authors' : ['Waylan Limberg', 'John Doe'],
'date' : ['October 2, 2007'],
'blank-value' : [''],
'base_url' : ['http://example.com']
}
Note that the keys are all lowercase and the values consist of a list of
strings where each item is one line for that key. This way, one could preserve
line breaks if desired. Or the items could be joined where appropriate. No
assumptions are made regarding the data. It is simply passed as found to the
Meta
attribute.
Perhaps the meta-data could be passed into a template system, or used by various markdown extensions. The possibilities are left to the imagination of the developer.
The following are extensions currently known to work with the Meta-Data Extension and the keywords they are known to support: