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++❝ FIXME ❞
— FIXME +
+
Most of the chapters in this book have centered around a piece of sample code. But XML isn’t about code; it’s about data. One common use of XML is “syndication feeds” that list the latest articles on a blog, forum, or other frequently-updated website. Most popular blogging software can produce a feed and update it whenever new articles, discussion threads, or blog posts are published. You can follow a blog by “subscribing” to its feed, and you can follow multiple blogs with a dedicated “feed aggregator” like Google Reader. + +
Here, then, is the XML data we’ll be working with in this chapter. It’s a feed — specifically, an Atom syndication feed. + +
<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
+ <title type="text">dive into mark</title>
+ <subtitle type="text">currently between addictions</subtitle>
+ <id>tag:diveintomark.org,2001-07-29:/</id>
+ <updated>2009-03-27T21:56:07Z</updated>
+ <link rel="alternate" type="text/html" href="http://diveintomark.org/"/>
+ <link rel="self" href="http://diveintomark.org/feed/" type="application/atom+xml"/>
+ <entry>
+ <author>
+ <name>Mark</name>
+ <uri>http://diveintomark.org/</uri>
+ </author>
+ <title type="html"><![CDATA[Dive into history, 2009 edition]]></title>
+ <link rel="alternate" type="text/html"
+ href="http://diveintomark.org/archives/2009/03/27/dive-into-history-2009-edition"/>
+ <id>tag:diveintomark.org,2009-03-27:/archives/20090327172042</id>
+ <updated>2009-03-27T21:56:07Z</updated>
+ <published>2009-03-27T17:20:42Z</published>
+ <category scheme="http://diveintomark.org" term="diveintopython"/>
+ <category scheme="http://diveintomark.org" term="docbook"/>
+ <category scheme="http://diveintomark.org" term="html"/>
+ <summary type="html">Putting an entire chapter on one page sounds bloated, but
+ consider this: my longest chapter so far would be 75 printed pages, and it
+ loads in under 5 seconds. On dialup.</summary>
+ </entry>
+ <entry>
+ <author>
+ <name>Mark</name>
+ <uri>http://diveintomark.org/</uri>
+ </author>
+ <title type="html"><![CDATA[Accessibility is a harsh mistress]]></title>
+ <link rel="alternate" type="text/html"
+ href="http://diveintomark.org/archives/2009/03/21/accessibility-is-a-harsh-mistress"/>
+ <id>tag:diveintomark.org,2009-03-21:/archives/20090321200928</id>
+ <updated>2009-03-22T01:05:37Z</updated>
+ <published>2009-03-21T20:09:28Z</published>
+ <category scheme="http://diveintomark.org" term="accessibility"/>
+ <summary type="html">The accessibility orthodoxy does not permit people to
+ question the value of features that are rarely useful and rarely used.</summary>
+ </entry>
+ <entry>
+ <author>
+ <name>Mark</name>
+ <uri>http://diveintomark.org/</uri>
+ </author>
+ <title type="html"><![CDATA[A gentle introduction to video encoding,
+ part 1: container formats]]></title>
+ <link rel="alternate" type="text/html"
+ href="http://diveintomark.org/archives/2008/12/18/give-part-1-container-formats"/>
+ <id>tag:diveintomark.org,2008-12-18:/archives/20081218155422</id>
+ <updated>2009-01-11T19:39:22Z</updated>
+ <published>2008-12-18T15:54:22Z</published>
+ <category scheme="http://diveintomark.org" term="asf"/>
+ <category scheme="http://diveintomark.org" term="avi"/>
+ <category scheme="http://diveintomark.org" term="encoding"/>
+ <category scheme="http://diveintomark.org" term="flv"/>
+ <category scheme="http://diveintomark.org" term="GIVE"/>
+ <category scheme="http://diveintomark.org" term="mp4"/>
+ <category scheme="http://diveintomark.org" term="ogg"/>
+ <category scheme="http://diveintomark.org" term="video"/>
+ <summary type="html">These notes will eventually become part of a
+ tech talk on video encoding.</summary>
+ </entry>
+</feed>FIXME + +
FIXME + +
+>>> import xml.etree.ElementTree as etree
+>>> tree = etree.parse("examples/feed.xml")
+>>> root = tree.getroot()
+>>> root
+<Element {http://www.w3.org/2005/Atom}feed at cd1eb0>
+
+
+FIXME + +
+>>> root.tag
+'{http://www.w3.org/2005/Atom}feed'
+>>> len(root)
+9
+>>> for child in root:
+... print(child)
+...
+<Element {http://www.w3.org/2005/Atom}title at e2b5d0>
+<Element {http://www.w3.org/2005/Atom}subtitle at e2b4e0>
+<Element {http://www.w3.org/2005/Atom}id at e2b6c0>
+<Element {http://www.w3.org/2005/Atom}updated at e2b6f0>
+<Element {http://www.w3.org/2005/Atom}link at e181b0>
+<Element {http://www.w3.org/2005/Atom}link at e2b4b0>
+<Element {http://www.w3.org/2005/Atom}entry at e2b720>
+<Element {http://www.w3.org/2005/Atom}entry at e2b510>
+<Element {http://www.w3.org/2005/Atom}entry at e2b750>
+
+
+FIXME + +
+>>> root.attrib
+{'{http://www.w3.org/XML/1998/namespace}lang': 'en'}
+>>> root[4]
+
+>>> root[4].attrib
+{'href': 'http://diveintomark.org/', 'type': 'text/html', 'rel': 'alternate'}
+>>> root[3]
+
+>>> root[3].attrib
+{}
+
+
+FIXME + +
+>>> tree.findall("{http://www.w3.org/2005/Atom}entry")
+[<Element {http://www.w3.org/2005/Atom}entry at e2b4e0>, <Element {http://www.w3.org/2005/Atom}entry at e2b510>, <Element {http://www.w3.org/2005/Atom}entry at e2b540>]
+
+>>> feed_links = tree.findall("{http://www.w3.org/2005/Atom}link")
+>>> feed_links
+[<Element {http://www.w3.org/2005/Atom}link at e181b0>, <Element {http://www.w3.org/2005/Atom}link at e2b4b0>]
+>>> feed_links[0].attrib
+{'href': 'http://diveintomark.org/', 'type': 'text/html', 'rel': 'alternate'}
+>>> feed_links[1].attrib
+{'href': 'http://diveintomark.org/feed/', 'type': 'application/atom+xml', 'rel': 'self'}
+
+>>> all_links = tree.findall("//{http://www.w3.org/2005/Atom}link")
+>>> all_links
+[<Element {http://www.w3.org/2005/Atom}link at e181b0>, <Element {http://www.w3.org/2005/Atom}link at e2b4b0>, <Element {http://www.w3.org/2005/Atom}link at e2b570>, <Element {http://www.w3.org/2005/Atom}link at e2b480>, <Element {http://www.w3.org/2005/Atom}link at e2b5a0>]
+>>> all_links[0].attrib
+{'href': 'http://diveintomark.org/', 'type': 'text/html', 'rel': 'alternate'}
+>>> all_links[1].attrib
+{'href': 'http://diveintomark.org/feed/', 'type': 'application/atom+xml', 'rel': 'self'}
+>>> all_links[2].attrib
+{'href': 'http://diveintomark.org/archives/2009/03/27/dive-into-history-2009-edition', 'type': 'text/html', 'rel': 'alternate'}
+>>> all_links[3].attrib
+{'href': 'http://diveintomark.org/archives/2009/03/21/accessibility-is-a-harsh-mistress', 'type': 'text/html', 'rel': 'alternate'}
+>>> all_links[4].attrib
+{'href': 'http://diveintomark.org/archives/2008/12/18/give-part-1-container-formats', 'type': 'text/html', 'rel': 'alternate'}
+
+
+FIXME + +
+>>> from lxml import etree
+.
+. FIXME (show how it's a drop-in replacement for everything we've done so far)
+.
+
+from here on out, use lxml.etree explicitly because these functions are specific to lxml
+>>> import lxml.etree
+>>> nsmap = {"atom": "http://www.w3.org/2005/Atom"}
+>>> tree = lxml.etree.parse("examples/feed.xml")
+>>> entries = tree.xpath("//atom:category[@term='accessibility']/..", namespaces=nsmap)
+>>> entries
+[<Element {http://www.w3.org/2005/Atom}entry at e2b630>]
+>>> entry = entries[0]
+>>> entry.xpath("./atom:title/text()", namespaces=nsmap)
+['Accessibility is a harsh mistress']
+
+
+FIXME + +
+>>> import lxml.etree
+>>> parser = lxml.etree.XMLParser(no_network=True, ns_clean=True, recover=True, remove_blank_text=True, remove_comments=True)
+>>> tree = lxml.etree.parse("examples/feed.xml", parser)
+
+
+FIXME + +
FIXME + +
+>>> import lxml.etree
+>>> new_feed = lxml.etree.Element("{http://www.w3.org/2005/Atom}feed", attrib={"{http://www.w3.org/XML/1998/namespace}lang": "en"})
+>>> print(lxml.etree.tounicode(new_feed))
+<ns0:feed xmlns:ns0="http://www.w3.org/2005/Atom" xml:lang="en"/>
+
+
+FIXME + +
+>>> import lxml.etree
+>>> new_feed = lxml.etree.Element("feed", nsmap=NSMAP)
+>>> print(lxml.etree.tounicode(new_feed))
+<feed xmlns="http://www.w3.org/2005/Atom"/>
+>>> new_feed.set("{http://www.w3.org/XML/1998/namespace}lang", "en")
+>>> print(lxml.etree.tounicode(new_feed))
+<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en"/>
+
+
+FIXME + +
+>>> title = lxml.etree.SubElement(new_feed, "title", attrib={"type":"html"})
+>>> print(lxml.etree.tounicode(new_feed))
+<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">dive into mark
+>>> print(lxml.etree.tounicode(new_feed, pretty_print=True))
+<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
+ <title type="html">dive into mark</title>
+</feed>
+
+
+© 2001–9 Mark Pilgrim + +