How do I generate a table of contents for HTML text in Python?

Assume that I have some HTML code, like this (generated from Markdown or Textile or something):

<h1>A header</h1>
<p>Foo</p>
<h2>Another header</h2>
<p>More content</p&g开发者_如何学Ct;
<h2>Different header</h2>
<h1>Another toplevel header
<!-- and so on -->

How could I generate a table of contents for it using Python?

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Use an HTML parser such as lxml or BeautifulSoup to find all header elements.

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Here's an example using lxml and xpath.

from lxml import etree
doc = etree.parse("test.xml")
for node in doc.xpath('//h1|//h2|//h3|//h4|//h5'):
    print node.tag, node.text