Question

我创建了一个看起来像这样的XML。

<?xml version='1.0' encoding='utf-8' standalone='no'?>
<flow xlmns="urn:opendaylight:flow:inventory">
  <strict>false</strict>
  <instructions>
    <instruction>
      <apply-action>
        <action>
          <order>0</order>
          <dec-nw-ttl/>
        </action>
      </apply-action>
    </instruction>
  </instructions>

我将它发送到一个带有两个参数的函数，flow（XML）和actions（我要添加的新动作列表）：

def add_flow_action(flow, actions):
   for newaction in actions:
      etree.SubElement(action, newaction)
   return flow

该函数用于在父命名操作下添加更多SubElements，因此它看起来像这样：

<?xml version='1.0' encoding='utf-8' standalone='no'?>
<flow xlmns="urn:opendaylight:flow:inventory">
  <strict>false</strict>
  <instructions>
    <instruction>
      <apply-action>
        <action>
          <order>0</order>
          <dec-nw-ttl/>
          <new-action-1/>      #Comment: NEW ACTION
          <new-action-2/>      #Comment: NEW ACTION
        </action>
      </apply-action>
    </instruction>
  </instructions>

这不起作用，它会抛出错误：TypeError：Argument＆＃39; _parent＆＃39;具有不正确的类型（预期lxml.etree._Element，获得列表）

有关如何更改功能的任何想法吗？

Answer 1

您应首先找到action元素，然后才能在其中创建SubElement：

from lxml import etree

data = """<?xml version='1.0' encoding='utf-8' standalone='no'?>
<flow xlmns="urn:opendaylight:flow:inventory">
  <strict>false</strict>
  <instructions>
    <instruction>
      <apply-action>
        <action>
          <order>0</order>
          <dec-nw-ttl/>
        </action>
      </apply-action>
    </instruction>
  </instructions>
</flow>
"""


def add_flow_action(flow, actions):
    action = flow.xpath('//action')[0]
    for newaction in actions:
        etree.SubElement(action, newaction)
    return flow

tree = etree.fromstring(data)
result = add_flow_action(tree, ['new-action-1', 'new-action-2'])

print etree.tostring(result)

打印：

<flow xlmns="urn:opendaylight:flow:inventory">
  <strict>false</strict>
  <instructions>
    <instruction>
      <apply-action>
        <action>
          <order>0</order>
          <dec-nw-ttl/>
          <new-action-1/>
          <new-action-2/>
        </action>
      </apply-action>
    </instruction>
  </instructions>
</flow>

lxml，将SubElement添加到SubElement

1 个答案: