XML：删除节点的子节点

Question

我想在一个xml文件中找到所有带有特定标签名的节点，比如说“foo”。如果这些“foo”标签下面还有名为“bar”的子节点，那么我想把这些“foo”节点给删除掉。最后的结果需要写入一个文件中。

<myDoc>
  <foo>
    <bar/> // remove this one
  </foo>
  <foo>
    <anyThing>
      <bar/> // don't remove this one
    </anyThing>
  </foo>
</myDoc> 

谢谢大家的任何建议。正如标签所示，我想用python来实现这个功能。

Answer 1

非常感谢 miles82 给了我解决问题的线索。这里是从我的 XML 文件中删除多个节点和/或多个元素的过程。我的大文件中的示例数据看起来是这样的：

<Data>
   <horsedata>
            <horse_name>DO NOT DELETE</horse_name>
            <stats_data>
                    <stat type="ALL_WEATHR">
                                GOT TO GO
            </stats_data>

            <sire><sirename>GOT TO GO</sirename><tmmark>M</tmmark><stud_fee>5000</stud_fee>

            </sire>
            <dam><damname>GOT TO GO</damname><damsire>WISED UP</damsire>

            </dam>

            <jockey><stat_breed>GOT TO GO</stat_breed><jock_disp>Lopez Charles C</jock_disp>
                    <stats_data>
                            <stat type="LAST30">
                                    GOT TO GO
                            </stat>                                                                                                             
                    </stats_data>
            </jockey>

            <workoutdata>Some More Text ... </workoutdata>
            <workoutdata>Yet More Text</workoutdata>

            <ppdata><racedate>20150801</racedate><trackcode>DO NOT DELETE</trackcode><trackname>Monmouth Park</trackname>
            <ppdata><racedate>20150715</racedate><trackcode>DO NOT DELET</trackcode><trackname>Belmont Park</trackname>er>2</racenumber><racebreed>TB</racebreed><country>USA</country><racetype>MCL</racetype><raceclass>MC</raceclass><claimprice>20000</claimprice><purse>29000</purse><classratin>76</classratin><trackcondi>FT</trackcondi><distance>600</distance><disttype>F</disttype><aboutdist/><courseid>D</courseid><surface>D</surface><pulledofft>0</pulledofft><winddirect/><windspeed>0</windspeed><trackvaria>12</trackvaria><sealedtrac/><racegrade>0</racegrade><agerestric>3U</agerestric><sexrestric/><statebredr/><abbrevcond/><postpositi>4</postpositi><favorite>0</favorite><weightcarr>119</weightcarr><jockfirst>Eduardo</jockfirst><jockmiddle/><jocklast>Ulloa</jocklast><jocksuffix/><jockdisp>Ulloa Eduardo</jockdisp><equipment>BF</equipment><medication/><fieldsize>6</fieldsize><posttimeod>54.25</posttimeod><shortcomme>3w upper, gave way</shortcomme><longcommen>slight bobble st, vied 4p early, cleared 2p turn, 3w 1/4,gave way</longcommen><gatebreak>3</gatebreak><position1>1</position1><lenback1>-50.00</lenback1><horsetime1>22.49</horsetime1><leadertime>22.49</leadertime><pacefigure>108</pacefigure><position2>1</position2><lenback2>-150.00</lenback2><horsetime2>46.56</horsetime2><leadertim2>46.56</leadertim2><pacefigur2>77</pacefigur2><positionst>5</positionst><lenbackstr>810.00</lenbackstr><horsetimes>60.75</horsetimes><leadertim3>59.40</leadertim3><dqindicato/><positionfi>6</positionfi><lenbackfin>1700.00</lenbackfin><horsetimef>75.50</horsetimef><leadertim4>72.67</leadertim4><speedfigur>33</speedfigur><turffigure>0.0</turffigure><winnersspe>71</winnersspe><foreignspe>-97</foreignspe><horseclaim>0</horseclaim><biasstyle>F</biasstyle><biaspath>N</biaspath><complineho>Lightning Ron</complineho><complinele>275.00</complinele><complinewe>124</complinewe><complinedq/><complineh2>Thomas Knight</complineh2><complinel2>25.00</complinel2><complinew2>119</complinew2><complined2/><complineh3>Heavy Hitter</complineh3><complinel3>450.00</complinel3><complinew3>124</complinew3><complined3/><linebefore/><lineafter/><domesticpp>1</domesticpp><oflfinish>6</oflfinish><runup_dist>64</runup_dist><rail_dist>-1</rail_dist><apprweight>0</apprweight><vd_claim/><vd_reason/></ppdata>
    </horsedata>
</Data>

我想保留的只有三个元素，分别是 horsename、workoutdata 和 ppdata ...

<?xml version="1.0"?>
tree=ET.parse('bel.xml')
root=tree.getroot()

horses=tree.findall('.//horsedata')

for horse in horses:
    stats = horse.findall('stats_data')
    sires = horse.findall('sire')
    dams = horse.findall('dam')
    jockeys = horse.findall('jockey')
    trainers = horse.findall('trainer')

    for stat in stats:
        horse.remove(stat)
    for sire in sires:
        horse.remove(sire)
    for dam in dams:
        horse.remove(dam)
    for jockey in jockeys:
        horse.remove(jockey)
    for trainer in trainers:
        horse.remove(trainer)  

tree.write('junk.xml')``

最后的输出结果是：

<Data>
    <horsedata>
            <horse_name>DO NOT DELETE</horse_name>
            <workoutdata>Some More Text ... </workoutdata>
            <workoutdata>Yet More Text</workoutdata>

            <ppdata><racedate>20150801</racedate><trackcode>DO NOT DELETE</trackcode><trackname>Monmouth Park</trackname></ppdata>
            <ppdata><racedate>20150715</racedate><trackcode>DO NOT DELET</trackcode><trackname>Belmont Park</trackname></ppdata>
    </horsedata>
</Data>

Answer 2

你可以使用 ElementTree 这个库：

from xml.etree.ElementTree import ElementTree
tree = ElementTree()
tree.parse('in.xml')

foos = tree.findall('foo')
for foo in foos:
  bars = foo.findall('bar')
  for bar in bars:
    foo.remove(bar)

tree.write('out.xml')