.. _advanced.namespaces:
Namespace Handling
==================
:program:`Universal Feed Parser` attempts to expose all possible data in feeds,
including elements in extension namespaces.
Some common namespaced elements are mapped to core elements. For further
information about these mappings, see :ref:`reference`.
Other namespaced elements are available as ``prefixelement``.
The namespaces defined in the feed are available in the parsed results as
``namespaces``, a dictionary of {prefix: namespaceURI}. If the feed defines a
default namespace, it is listed as ``namespaces['']``.
Accessing namespaced elements
-----------------------------
::
>>> import feedparser
>>> d = feedparser.parse('http://feedparser.org/docs/examples/prism.rdf')
>>> d.feed.prism_issn
u'0028-0836'
>>> d.namespaces
{'': u'http://purl.org/rss/1.0/',
'prism': u'http://prismstandard.org/namespaces/1.2/basic/',
'rdf': u'http://www.w3.org/1999/02/22-rdf-syntax-ns#'}
The prefix used to construct the variable name is not guaranteed to be the same
as the prefix of the namespaced element in the original feed. If
:program:`Universal Feed Parser` recognizes the namespace, it will use the
namespace's preferred prefix to construct the variable name. It will also list
the namespace in the ``namespaces`` dictionary using the namespace's preferred
prefix.
In the previous example, the namespace
(http://prismstandard.org/namespaces/1.2/basic/) was defined with the
namespace's preferred prefix (prism), so the prism:issn element was accessible
as the variable ``d.feed.prism_issn``. However, if the namespace is defined
with a non-standard prefix, :program:`Universal Feed Parser` will still
construct the variable name using the preferred prefix, *not* the actual prefix
that is used in the feed.
This will become clear with an example.
Accessing namespaced elements with non-standard prefixes
--------------------------------------------------------
::
>>> import feedparser
>>> d = feedparser.parse('http://feedparser.org/docs/examples/nonstandard_prefix.rdf')
>>> d.feed.prism_issn
u'0028-0836'
>>> d.feed.foo_issn
Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "feedparser.py", line 158, in __getattr__
raise AttributeError, "object has no attribute '%s'" % key
AttributeError: object has no attribute 'foo_issn'
>>> d.namespaces
{'': u'http://purl.org/rss/1.0/',
'prism': u'http://prismstandard.org/namespaces/1.2/basic/',
'rdf': u'http://www.w3.org/1999/02/22-rdf-syntax-ns#'}
This is the complete list of namespaces that :program:`Universal Feed Parser`
recognizes and uses to construct the variable names for data in these
namespaces:
=============== =====================================================
Prefix Namespace
=============== =====================================================
admin http://webns.net/mvcb/
ag http://purl.org/rss/1.0/modules/aggregation/
annotate http://purl.org/rss/1.0/modules/annotate/
audio http://media.tangent.org/rss/1.0/
blogChannel http://backend.userland.com/blogChannelModule
cc http://web.resource.org/cc/
co http://purl.org/rss/1.0/modules/company
content http://purl.org/rss/1.0/modules/content/
cp http://my.theinfo.org/changed/1.0/rss/
creativeCommons http://backend.userland.com/creativeCommonsRssModule
dc http://purl.org/dc/elements/1.1/
dcterms http://purl.org/dc/terms/
email http://purl.org/rss/1.0/modules/email/
ev http://purl.org/rss/1.0/modules/event/
feedburner http://rssnamespace.org/feedburner/ext/1.0
fm http://freshmeat.net/rss/fm/
foaf http://xmlns.com/foaf/0.1/
geo http://www.w3.org/2003/01/geo/wgs84_pos#
icbm http://postneo.com/icbm/
image http://purl.org/rss/1.0/modules/image/
itunes http://example.com/DTDs/PodCast-1.0.dtd
itunes http://www.itunes.com/DTDs/PodCast-1.0.dtd
l http://purl.org/rss/1.0/modules/link/
media http://search.yahoo.com/mrss
pingback http://madskills.com/public/xml/rss/module/pingback/
prism http://prismstandard.org/namespaces/1.2/basic/
rdf http://www.w3.org/1999/02/22-rdf-syntax-ns#
rdfs http://www.w3.org/2000/01/rdf-schema#
ref http://purl.org/rss/1.0/modules/reference/
reqv http://purl.org/rss/1.0/modules/richequiv/
search http://purl.org/rss/1.0/modules/search/
slash http://purl.org/rss/1.0/modules/slash/
soap http://schemas.xmlsoap.org/soap/envelope/
ss http://purl.org/rss/1.0/modules/servicestatus/
str http://hacks.benhammersley.com/rss/streaming/
sub http://purl.org/rss/1.0/modules/subscription/
sy http://purl.org/rss/1.0/modules/syndication/
szf http://schemas.pocketsoap.com/rss/myDescModule/
taxo http://purl.org/rss/1.0/modules/taxonomy/
thr http://purl.org/rss/1.0/modules/threading/
ti http://purl.org/rss/1.0/modules/textinput/
trackback http://madskills.com/public/xml/rss/module/trackback/
wfw http://wellformedweb.org/CommentAPI/
wiki http://purl.org/rss/1.0/modules/wiki/
xhtml http://www.w3.org/1999/xhtml
xlink http://www.w3.org/1999/xlink
xml http://www.w3.org/XML/1998/namespace
=============== =====================================================
.. note::
:program:`Universal Feed Parser` treats namespaces as case-insensitive to
match the behavior of certain versions of :program:`iTunes`.
.. warning::
Data from namespaced elements is not :ref:`sanitized <advanced.sanitization>`
(even if it contains :abbr:`HTML (HyperText Markup Language)` markup).
