lxml to parse html

[contro opinion]

import lxml.html
myxml='''
<cooperate>
<job DecreaseHour="1" table="tpa_radio_sum">
</job>

<job DecreaseHour="2" table="tpa_radio_sum">
</job>


<job DecreaseHour="3" table="tpa_radio_sum">
</job>
</cooperate>
'''
root=lxml.html.fromstring(myxml)
nodes1=root.xpath('//job[@DecreaseHour="1"]')
nodes2=root.xpath('//job[@table="tpa_radio_sum"]')
print "nodes1=",nodes1
print "nodes2=",nodes2


>>>
nodes1= []
nodes2= [<Element job at 0x1241240>, <Element job at 0x1362690>, <Element
job at 0x13626c0>]

would you mind to tell me  why nodes1=[]??
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