import lxml.html<br>myxml='''<br><cooperate><br><job DecreaseHour="1" table="tpa_radio_sum"><br></job><br><br><job DecreaseHour="2" table="tpa_radio_sum"><br>
</job><br><br><br><job DecreaseHour="3" table="tpa_radio_sum"><br></job><br></cooperate><br>'''<br>root=lxml.html.fromstring(myxml)<br>nodes1=root.xpath('//job[@DecreaseHour="1"]')<br>
nodes2=root.xpath('//job[@table="tpa_radio_sum"]')<br>print "nodes1=",nodes1<br>print "nodes2=",nodes2<br><br><br>>>> <br>nodes1= []<br>nodes2= [<Element job at 0x1241240>, <Element job at 0x1362690>, <Element job at 0x13626c0>]<br>
<br>would you mind to tell me  why nodes1=[]??<br><br>