from xml.dom import minidom
mixml="""<conversation>
<message line="1">
<author>jose</author>
<time>03:10</time>
</message>
<message line="2">
<author>juan</author>
<time>03:20</time>
</message>
<message line="3">
<author>pepe</author>
<time>03:20</time>
</message>
</conversation>"""
xmldoc = minidom.parseString(mixml)
# obtenemos el atributo line de <message line="...">
print ("Atributo")
print ("----------------------")
itemlist = xmldoc.getElementsByTagName("message")
for i in itemlist:
print (i.attributes["line"].value)
# obtenemos el valor del tag <text>
print
print ("Contenido")
print ("----------------------")
itemlist = xmldoc.getElementsByTagName("author")
for i in itemlist:
print (i.firstChild.nodeValue)