由于OP包含其Python代码，因此已更新.

updated now that OP's included his Python code.

您的问题是lxml.etree.tostring和.write方法仅在XML上有意义，而在output method="text"的XSLT结果中却没有意义，而output method="text"可能没有像XML那样的单个根元素.由于某些令人困惑的原因，函数 do 具有一个method=关键字参数，但是它没有任何用处.

Your problem is that lxml.etree.tostring and also the .write method are only meaningful on XML, not on an XSLT result with output method="text" which might not have a single root element like XML does. For some confusing reason, the functions do have a method= keyword argument but it does not do anything useful.

这是您应该做的:

import lxml.etree as etree
data = etree.parse('data.xml')
transform = etree.XSLT(etree.parse('txt.xslt'))
res = transform(data)
bytes(res)

b'\nCEO and 1Director of Operations and 2Human Resources Manager and 3\n'

如果您对真实示例感兴趣，请我最近做了补丁.

If you're interested in a real world example, I recently made a patch.