如何在Python中获取没有根节点的XML

Question

给定以下数据：

<rdf:RDF
    xmlns="http://purl.org/rss/1.0/"
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
    xmlns:dc="http://purl.org/dc/elements/1.
<channel rdf:about="http://www.gmanews.tv/">
        <title>GMANews.TV</title>
        <description> GMA News.tv bring you the latest news from GMA News teams and highlights of your favorite shows. Subscribe now and stay up-to-date with GMA News.tv.</description>
        <link>http://www.gmanews.tv/</link>
</channel>

<item rdf:about="http://www.gmanews.tv/story/232365/world/magnitude-59-quake-hits-chilean-coast-no-damage">
        <dc:format>text/html</dc:format>
        <dc:date>2011-09-14T16:39:22+08:00</dc:date>
        <dc:source>http://www.gmanews.tv/story/232365/world/magnitude-59-quake-hits-chilean-coast-no-damage </dc:source>
                <title><![CDATA[Magnitude-5.9 quake hits Chilean coast, no damage]]></title>
        <link>http://www.gmanews.tv/story/232365/world/magnitude-59-quake-hits-chilean-coast-no-damage </link>
        <description><![CDATA[SANTIAGO - A magnitude 5.9 quake hit just off the coast of central Chile early on Wednesday, but the state emergency office said there were no reports of damage.]]></description>
    </item>
        <item rdf:about="http://www.gmanews.tv/story/232362/nation/house-minority-blames-pnoys-advisers-for-legal-setbacks">
        <dc:format>text/html</dc:format>
        <dc:date>2011-09-14T16:04:51+08:00</dc:date>
        <dc:source>http://www.gmanews.tv/story/232362/nation/house-minority-blames-pnoys-advisers-for-legal-setbacks </dc:source>
                <title><![CDATA[House minority blames PNoy's advisers for legal 'setbacks']]></title>
        <link>http://www.gmanews.tv/story/232362/nation/house-minority-blames-pnoys-advisers-for-legal-setbacks </link>
        <description><![CDATA[Members of the opposition at the House of Representatives on Wednesday blamed President Benigno Aquino III's advisers for the various legal "setbacks&quot; suffered by his administration and advised him to consider replacing some of his advisers.]]></description>
    </item>
        <item rdf:about="http://www.gmanews.tv/story/232356/nation/ex-sharia-judge-20-others-may-testify-in-poll-fraud-probe">
        <dc:format>text/html</dc:format>
        <dc:date>2011-09-14T15:19:45+08:00</dc:date>
        <dc:source>http://www.gmanews.tv/story/232356/nation/ex-sharia-judge-20-others-may-testify-in-poll-fraud-probe </dc:source>
                <title><![CDATA[Ex-Shari'a judge, 20 others may testify in poll fraud probe]]></title>
        <link>http://www.gmanews.tv/story/232356/nation/ex-sharia-judge-20-others-may-testify-in-poll-fraud-probe </link>
        <description><![CDATA[The former Shari'a court judge who claimed to have helped Gloria Macapagal-Arroyo cheat in the 2004 presidential elections and at least 20 others may serve as witnesses in the joint investigation by the Commission on Elections and Department of Justice on the alleged poll fraud, Comelec chief Sixto Brillantes Jr. said Wednesday.]]></description>
    </item>
</rdf:RDF>

现在我想获取 标签内所有元素的详细信息。这很简单，但我是 python 新手。我不太确定如何解析 rdf，然后提取其中的所有 。

编辑： 我无法使用任何第三方库，因为我的脚本将在嵌入式系统上运行。

Answer 1

lxml 提供了一种处理所有 XML 内容的好方法。您发布的 XML 示例：

from lxml import etree

document = etree.parse('your-example-xml.rdf')
root = document.getroot()

# Namespace shortcuts
ns = root.nsmap.get(None)
rdf = root.nsmap.get('rdf')

for item in root.xpath('purl:item', namespaces={'purl': ns}):
    print item.attrib.get('{%s}about' % rdf)
    print item.xpath('purl:description/text()', namespaces={'purl': ns})
    print

但是，如果您仅解析 RDF，则可能有可用的 RDF 特定库。

Answer 2

由于第三方库不是一个选项，这里是使用 Python 内置库完成的相同代码元素树：

from xml.etree import ElementTree as etree

document = etree.parse(open('your-example-xml.rdf'))
root = document.getroot()

ns_purl = 'http://purl.org/rss/1.0/'
ns_rdf = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'

for item in root.findall('{%s}item' % ns_purl):
    print item.attrib.get('{%s}about' % ns_rdf)
    print item.find('{%s}description' % ns_purl).text
    print