<p>主持人:</p>
<pre><code>./host[address[@vendor="QEMU Virtual NIC"]]
</code></pre>
<p>IPv4地址:</p>
^{pr2}$
<p>交互使用<code>lxml</code>:</p>
<pre><code>>>> from lxml import etree
>>> doc = etree.XML("""<doc><host><status state="up" reason="arp-response"/>
... <address addr="192.168.2.93" addrtype="ipv4"/>
... <address addr="52:54:00:E2:17:31" addrtype="mac" vendor="QEMU Virtual NIC"/>
... <hostnames>
... </hostnames>
... <times srtt="1023" rttvar="5000" to="100000"/>
... </host>
... <host><status state="up" reason="arp-response"/>
... <address addr="192.168.2.96" addrtype="ipv4"/>
... <address addr="52:54:00:45:86:8A" addrtype="mac" vendor="QEMU Virtual NIC"/>
... <hostnames>
... </hostnames>
... <times srtt="155" rttvar="5000" to="100000"/>
... </host>
... <host><status state="up" reason="arp-response"/>
... <address addr="192.168.2.103" addrtype="ipv4"/>
... <address addr="52:54:00:61:7A:E5" addrtype="mac" vendor="QEMU Virtual NIC"/>
... <hostnames>
... </hostnames>
... <times srtt="391" rttvar="5000" to="100000"/>
... </host></doc>""")
>>> doc.xpath('./host[address[@vendor="QEMU Virtual NIC"]]')
[<Element host at 0xb72c0af4>, <Element host at 0xb72c0b1c>, <Element host at 0xb72c0b44>]
>>> doc.xpath('./host[address[@vendor="QEMU Virtual NIC"]]/address[@addrtype="ipv4"]/@addr')
['192.168.2.93', '192.168.2.96', '192.168.2.103']
</code></pre>