如何在python（lxml）中过滤后访问kml/xml属性？

我环顾了一下，似乎无法找到解决我的问题的方法。我的根本问题是，我需要找到所有KML元素的名称，其子面包含具有给定纬度/经度的点。如何在python（lxml）中过滤后访问kml/xml属性？

环顾四周我发现使用keytree，shapely和lxml我可以将所有KML元素过滤到有问题的多边形，然后访问其父母。但是，当我尝试访问父级的属性时，我总是收到一个空列表。我试过以下内容：

def __init__(self): 
    root=etree.fromstring(open("Example.kml", "r").read()) 
    kmlns = root.tag.split("}")[0][1:] 
    polygons=root.findall(".//{%s}Polygon"%kmlns) 
    p = Point(-128.1605,52.474) #this point exists in one of the polygons 
    hits = filter(
     lambda e: shape(keytree.geometry(e)).contains(p), 
     polygons) 

    print hits 
    hit_parent=hits[0].getparent() 
    print hit_parent.attrib#this prints {}

我能够通过pycharm中的调试器找到多边形所在的行;根据这一点，hits [0]有一个源代码行属性，当我在我的KML文档中找到该行号时，该多边形确实包含该点。滚动到多边形的父级，我发现它有属性（即不是空列表）。我是xml和kml解析的新手;我看错了地方？下面是从KML多边形与其父：

<Placemark> 
      <name>THIS IS THE NAME</name> 
      <visibility>0</visibility> 
      <styleUrl>#falseColor184010</styleUrl> 
      <ExtendedData> 
       <SchemaData schemaUrl="#S_AL_TA_BC_2_41_eng_SSSSISSSSSSSSSSSSSSSSSSSSS10"> 
        <SimpleData name="ACQTECH">Computed</SimpleData> 
        <SimpleData name="METACOVER">Partial</SimpleData> 
        <SimpleData name="CREDATE">20030416</SimpleData> 
        <SimpleData name="REVDATE">20130504</SimpleData> 
        <SimpleData name="ACCURACY">-1</SimpleData> 
        <SimpleData name="PROVIDER">Federal</SimpleData> 
        <SimpleData name="DATASETNAM">BC</SimpleData> 
        <SimpleData name="SPECVERS">1.1</SimpleData> 
        <SimpleData name="NID">7103157bba3511d892e2080020a0f4c9</SimpleData> 
        <SimpleData name="ALCODE">07876</SimpleData> 
        <SimpleData name="LANGUAGE1">English</SimpleData> 
        <SimpleData name="NAME1">NEEKAS 4</SimpleData> 
        <SimpleData name="LANGUAGE2">French</SimpleData> 
        <SimpleData name="NAME2">NEEKAS NO 4</SimpleData> 
        <SimpleData name="LANGUAGE3">No Language</SimpleData> 
        <SimpleData name="NAME3">NULL</SimpleData> 
        <SimpleData name="LANGUAGE4">No Language</SimpleData> 
        <SimpleData name="NAME4">NULL</SimpleData> 
        <SimpleData name="LANGUAGE5">No Language</SimpleData> 
        <SimpleData name="NAME5">NULL</SimpleData> 
        <SimpleData name="JUR1">BC</SimpleData> 
        <SimpleData name="JUR2"></SimpleData> 
        <SimpleData name="JUR3"></SimpleData> 
        <SimpleData name="JUR4"></SimpleData> 
        <SimpleData name="ALTYPE">Indian Reserve</SimpleData> 
        <SimpleData name="WEBREF">http://clss.nrcan.gc.ca/map-carte/mapbrowser-navigateurcartographique-eng.php?cancode=07876</SimpleData> 
       </SchemaData> 
      </ExtendedData> 
      <Polygon> 
       <outerBoundaryIs> 
        <LinearRing> 
         <coordinates> 
          -128.1615722,52.47385589999999,0 -128.1618475,52.47338730000003,0 -128.1623126999999,52.47275560000004,0 -128.1622705,52.47253640000001,0 -128.162017,52.47243320000002,0 -128.1619326,52.4722527,0 -128.1618904,52.4721108,0 -128.161827,52.47202060000003,0 -128.1615523,52.47204629999998,0 -128.1613199,52.47211069999996,0 -128.1607705,52.47205899999999,0 -128.1604538,52.47172369999999,0 -128.1600750999999,52.47149440000001,0 -128.1600821,52.47510580000001,0 -128.1615621,52.47510469999996,0 -128.1615294999999,52.474926,0 -128.1615508,52.47452629999999,0 -128.1615298,52.47416529999997,0 -128.1615722,52.47385589999999,0 
         </coordinates> 
        </LinearRing> 
       </outerBoundaryIs> 
      </Polygon>

我想“这是NAME”从多边形的父。

来源

2016-07-26 Albert Rothman

您的目标文本不是任何元素的属性。给定<Polygon>作为上下文元素，您想要转到父元素<Placemark>，然后获取其子元素<name>。这可以使用XPath在单行中完成：

.... 
print hits 
hit_parent = hits[0].find("./../{%s}name"%kmlns) 
print hit_parent.text

来源

2016-07-27 00:31:49 har07

非常感谢！ –

如何在python（lxml）中过滤后访问kml/xml属性？

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