Python ElementTree：在循环中替换元素

Question

I'm trying to create a script that loops creating an xml file, with incrementing values for two elements. (an IP address using netaddr, and the tag/member element that increments, tag01 - tag10)

from netaddr import IPNetwork
import xml.dom.minidom
import lxml.etree as etree
import xml.etree.cElementTree as ET

ip = IPNetwork('10.10.10.0/24')
count = 1
tag = range(1,10)

uid = ET.Element("message")
type = ET.SubElement(uid, "type").text = "update"
payload = ET.SubElement(uid, "payload")
register = ET.SubElement(payload, "register")
entry = ET.SubElement(register, "entry", ip="11.11.11.11")
tag = ET.SubElement(entry, "tag")
ET.SubElement(tag, "member").text = "tag1"
tree = ET.ElementTree(uid)

while count <= 10:
    elemtag = tree.findall(".//member")
    for elemt in elemtag:
        elemt.text = 'tag{}'.format(tag)
    elemip = tree.findall(".//entry")
    for elemi in elemip:
        elemi.text = 'ip="{}"'.format(ip)
    count += 1
    ET.dump(uid)
    print(count)

    #tree.write("tmp.xml")
    #x = etree.parse("tmp.xml")
    #print etree.tostring(x, pretty_print=True)
    #etree.parse("tmp.xml").write("pretty.xml", encoding="utf-8", pretty_print=True)
    #os.system('tool.py -f pretty.xml')

I figured out how to create the xml I needed using ElementTree, and if I comment out my loop and write the the resulting xml, it's correct, looks good, and works with the tool that consumes it (yay!).

<message>
  <type>update</type>
  <payload>
    <register>
      <entry ip="11.11.11.11">
        <tag>
          <member>tag1</member>
        </tag>
      </entry>
    </register>
  </payload>
</message>

However, when I add my loop to replace the values for the two elements, I just cant seem to get it right, and I'm clobbering the tags/elements in the tree.

<message>
  <type>update</type>
  <payload>
    <register>
      <entry ip="11.11.11.11">ip="10.10.10.0/24"<tag><member>tag&lt;Element 'tag' at 
0x7f7b29d66c90&gt;</member></tag></entry>
    </register>
  </payload>
</message>

I keep trying different things to replace the elements, but they just end up as different permutations of wrong, and I just can't seem to get it right. Hoping someone can help me figure out what I'm missing. Thanks in advance!

Answer 1

< Entry > it's an element and "ip" it's an attribute of that element.
We can change the attribute for the element in the following way:

tree.find('.//entry').attrib['ip'] = "22.22.22.22"

"tag1" it's .text inside of the < member > element but we reassigned the tag variable at this line:

tag = ET.SubElement(entry, "tag")

According that we assigned own tag object to the tag element's text instead of tag number.
I updated your code. Now this solution generates new XML < message > at each "count" iteration. I hope it will help.

from netaddr import IPNetwork
import xml.etree.cElementTree as ET

ip = IPNetwork('10.10.10.0/24')
tag_lst = list(range(1, 11))
count = 1

uid = ET.Element("message")
type = ET.SubElement(uid, "type").text = "update"
payload = ET.SubElement(uid, "payload")
register = ET.SubElement(payload, "register")
entry = ET.SubElement(register, "entry", ip="11.11.11.11")
tag = ET.SubElement(entry, "tag")
ET.SubElement(tag, "member").text = "tag1"
tree = ET.ElementTree(uid)

while count <= 10:
    tree.find('.//member').text = "tag"+str(count)
    tree.find('.//entry').attrib['ip'] = format(ip[count])
    count += 1
    ET.dump(uid)
    print(count)

XML output is:

<message><type>update</type><payload><register><entry ip="10.10.10.1"><tag><member>tag1</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.2"><tag><member>tag2</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.3"><tag><member>tag3</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.4"><tag><member>tag4</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.5"><tag><member>tag5</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.6"><tag><member>tag6</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.7"><tag><member>tag7</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.8"><tag><member>tag8</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.9"><tag><member>tag9</member></tag></entry></register></payload></message>
<message><type>update</type><payload><register><entry ip="10.10.10.10"><tag><member>tag10</member></tag></entry></register></payload></message>