Mine

$ cat test.pystr = """<?xml version="1.0" encoding="UTF-8"?><network>    <description name="Boston">        This is the configuration of our network in the Boston office.    </description>    <host name="agatha" type="server" os="linux">        <interface name="eth0" type="Ethernet">            <arec>agatha.example.edu</arec>            <cname>mail.example.edu</cname>            <addr>192.168.0.4</addr>        </interface>        <service>SMTP</service>        <service>POP3</service>        <service>IMAP4</service>    </host>    <host name="gil" type="server" os="linux">        <interface name="eth0" type="Ethernet">            <arec>gil.example.edu</arec>            <cname>www.example.edu</cname>            <addr>192.168.0.5</addr>        </interface>        <service>HTTP</service>        <service>HTTPS</service>    </host>    <host name="baron" type="server" os="linux">        <interface name="eth0" type="Ethernet">            <arec>baron.example.edu</arec>            <cname>dns.example.edu</cname>            <cname>ntp.example.edu</cname>            <cname>ldap.example.edu</cname>            <addr>192.168.0.6</addr>        </interface>        <service>DNS</service>        <service>NTP</service>        <service>LDAP</service>        <service>LDAPS</service>    </host>    <host name="mr-tock" type="server" os="openbsd">        <interface name="fxp0" type="Ethernet">            <arec>mr-tock.example.edu</arec>            <cname>fw.example.edu</cname>            <addr>192.168.0.1</addr>        </interface>        <service>firewall</service>    </host>    <host name="krosp" type="client" os="osx">        <interface name="en0" type="Ethernet">            <arec>krosp.example.edu</arec>            <addr>192.168.0.100</addr>        </interface>        <interface name="en1" type="AirPort">            <arec>krosp.wireless.example.edu</arec>            <addr>192.168.100.100</addr>        </interface>    </host>    <host name="zeetha" type="client" os="osx">        <interface name="en0" type="Ethernet">            <arec>zeetha.example.edu</arec>            <addr>192.168.0.101</addr>        </interface>        <interface name="en1" type="AirPort">            <arec>zeetha.wireless.example.edu</arec>            <addr>192.168.100.101</addr>        </interface>    </host></network>"""sel = "/child::network/child::host/child::interface/following-sibling::interface/parent::host/attribute::name"from lxml.etree import fromstringx = fromstring(str)print x.xpath("/child::network/child::host/child::interface/ancestor::host/child::interface/following-sibling::interface/preceding::host/attribute::name")$ python test.py['agatha', 'gil', 'baron', 'mr-tock', 'krosp']