【发布时间】：2021-09-30 15:09:11
【问题描述】：
RDFLib 似乎在 support 解析 RDFa 数据。在实现一个 sn-p 来解析一个带有 RDFa 注释的 HTML 页面时，我遇到了这个问题：
Traceback (most recent call last):
File "/home/zonk/.local/lib/python3.8/site-packages/rdflib/plugin.py", line 107, in get
p = _plugins[(name, kind)]
KeyError: ('html', <class 'rdflib.parser.Parser'>)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "basic-rdfa.py", line 7, in <module>
g.parse("beatles.rdfa.html", format='html')
File "/home/zonk/.local/lib/python3.8/site-packages/rdflib/graph.py", line 1209, in parse
parser = plugin.get(format, Parser)()
File "/home/zonk/.local/lib/python3.8/site-packages/rdflib/plugin.py", line 109, in get
raise PluginException("No plugin registered for (%s, %s)" % (name, kind))
rdflib.plugin.PluginException: No plugin registered for (html, <class 'rdflib.parser.Parser'>)
使用如下sn-p：
from rdflib import Graph, plugin
g = Graph()
g.parse("beatles.rdfa.html", format='html')
for subj, pred, obj in g:
if(subj, pred, obj) not in g:
raise Exception("Zonk!")
print(f"Graph g has {len(g)} statements.")
print(g.serialize(format="turtle"))
使用以下虚拟数据：
<!DOCTYPE html>
<html lang="en">
<head>
<title>John Lennon</title>
</head>
<div vocab="http://schema.org/">
<div typeof="Person">
<link property="rdfa:copy" href="#lennon"/>
<link property="rdfa:copy" href="#band"/>
</div>
<p resource="#lennon" typeof="rdfa:Pattern">
Name: <span property="name">John Lennon</span>
<p>
<div resource="#band" typeof="rdfa:Pattern">
<div property="band" typeof="MusicGroup">
<link property="rdfa:copy" href="#beatles"/>
</div>
</div>
<div resource="#beatles" typeof="rdfa:Pattern">
<p>Band: <span property="name">The Beatles</span></p>
<p>Size: <span property="size">4</span> players</p>
</div>
</div>
</html>确实，plugin.py 中没有一行记录任何 HTML 数据。在这种情况下如何解析带有 rdfa 注释的数据？
提前谢谢你。
【问题讨论】：
标签： python html-parsing semantic-markup rdflib rdfa