Close a tag with no text in lxml

问题

I am trying to output a XML file using Python and lxml

However, I notice one thing that if a tag has no text, it does not close itself. An example of this would be:

root = etree.Element('document')
rootTree = etree.ElementTree(root)
firstChild = etree.SubElement(root, 'test')

The output of this is:

<document>
<test/>
</document

I want the output to be:

<document>
<test>
</test>
</document>

So basically I want to close a tag which has no text, but is used to the attribute value. How do I do that? And also, what is such a tag called? I would have Googled it, but I don't know how to search for it.

回答1:

Note that <test></test> and <test/> mean exactly the same thing. What you want is for the test-tag to actually do have a text that consists in a single linebreak. However, an empty tag with no text is usually written as <test/> and it makes very little sense to insist on it to appear as <test></test>.

回答2:

To clarify @ymv answer in case it might be of help to others:

from lxml import etree

root = etree.Element('document')
rootTree = etree.ElementTree(root)
firstChild = etree.SubElement(root, 'test')

print(etree.tostring(root, method='html'))
### b'<document><test></test></document>'

回答3:

Use lxml.html.tostring to serialize to HTML

import lxml.html
root = lxml.html.fromstring(mydocument)
print(lxml.html.tostring(root))

回答4:

Use empty string '' like this:

root = etree.Element('document')
etree.SubElement(root, 'test').text = ''

来源：https://stackoverflow.com/questions/2771383/close-a-tag-with-no-text-in-lxml