如何使用 lxml 从磁盘加载 .xml 文件作为元素树？

Question

我的驱动器上有一系列 XML 个文件，我想对其执行以下操作：

作为元素树加载到lxml并用xpath解析
加载另一个 XML 文件作为元素树并使用 xpath 解析以找到正确的位置以将信息附加到
我从一系列 XML 文件中解析的信息应该设置为变量，这样我就可以运行在追加回大文件之前对结果进行一些逻辑处理。xml文件

我在文件类型方面遇到了一些问题/将 XML 文件作为元素树正确加载，以便 lxml 可以对其进行操作。我已经尝试了几种不同的方法，但一直运行遇到各种问题。当前问题如下：

TypeError: Argument '_parent' has incorrect type (expected lxml.etree._Element, got list)

from lxml import etree
from lxml import html
import requests

file = 'bgg.xml'
# parse the xml file from disk as an element tree in lxml?
treebgg = etree.parse(file)

# create a list of IDs to iterate through from the bgg.xml file
gameList = treebgg.xpath("//root/BGG/@ID")

# iterate through the IDs
for x in reversed(gameList):
    url = 'https://somewhere.com/xmlapi/' + str(x)
    page = requests.get(url)
    # pull an xml file from a web url and turn it into an element tree in lxml
    tree = html.fromstring(page.content)
    # set my root variable so I can append children to this location
    root = tree.xpath("//root/BGG[@ID=x]")
    name = tree.xpath("//somewhere/name[@primary='true']"
    # append child info into bgg.xml
    child = etree.SubElement(root, "Name")
    child.text = name

# write bgg.xml back to file

Answer 1

获取 bgg.xml 树的根：

rootbgg = treebgg.getroot()

并使用它将 children 附加到：

child = etree.SubElement(rootbgg, "Name")

I'm having another problem...how do I select the correct element? I don't want to append to the root of the xml file itself.

您现在需要重新设计迭代元素的方式：

gameList = treebgg.xpath("//root/BGG")

# iterate through the IDs
for game in reversed(gameList):
    url = 'https://somewhere.com/xmlapi/' + game.attrib["id"]
    page = requests.get(url)
    tree = html.fromstring(page.content)
    # TODO: get the name

    # append child info into bgg.xml
    child = etree.SubElement(game, "Name")
    child.text = name

如何使用 lxml 从磁盘加载 .xml 文件作为元素树？

How do I load an .xml file from disk as an element tree using lxml?

python

xml

xpath

lxml

xml-parsing