使用 ElementTree 从 xml 标签获取所有 children

Question

我正在尝试使用 ElementTree 解析 XML 文件，有时我只得到第一个 child 而不是标签内的所有 children - 以下是我的 XML结构：-

    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <sentences>
        <sentence id="2339">
            <text>I charge it at night and skip taking the cord with me because of the good battery life.</text>
            <aspectTerms>
                <aspectTerm term="cord" polarity="neutral" from="41" to="45"/>
                <aspectTerm term="battery life" polarity="positive" from="74" to="86"/>
            </aspectTerms>
        </sentence>
        <sentence id="812">
            <text>I bought a HP Pavilion DV4-1222nr laptop and have had so many problems with the computer.</text>
        </sentence>
        <sentence id="1316">
            <text>The tech guy then said the service center does not do 1-to-1 exchange and I have to direct my concern to the "sales" team, which is the retail shop which I bought my netbook from.</text>
            <aspectTerms>
                <aspectTerm term="service center" polarity="negative" from="27" to="41"/>
                <aspectTerm term="&quot;sales&quot; team" polarity="negative" from="109" to="121"/>
                <aspectTerm term="tech guy" polarity="neutral" from="4" to="12"/>
            </aspectTerms>
        </sentence>
    </sentences>

我想在每个 'aspectTerm' 标签中得到 'term'。以下是我的代码：-

    import xml.etree.ElementTree as ET
    tree = ET.parse('Laptops_Train.xml')
    root = tree.getroot()
    df = pd.DataFrame()

    def getAspect(sentences):
        reviewList = []
        text = sentence.find('text').text
        reviewList.append(text)
        for aspectTerms in sentence.iter('aspectTerms'):
            #for aspectTerm in aspectTerms.iter('aspectTerm'): 
            aspect = aspectTerms.find('aspectTerm').get('term')
            print(aspect)
            return aspect

    aspectList = []
    for sentences in root.iter('sentences'):
        for sentence in sentences.iter('sentence'):
            aspectList.append(getAspect(sentence))

实际结果：

cord
class 'NoneType'
service center

预期结果：

[cord, battery life]
[]
[service center,&quot;sales&quot; team, tech guy]

提前致谢

Answer 1

使用具有 xpath 的 lxml 库更容易做到这一点。

>>> from lxml import etree
>>> tree = etree.parse('Laptops_Train.xml')
>>> for aspectTerms in tree.xpath('.//aspectTerms'):
...     aspectTerms.xpath('aspectTerm/@term')
... 
['cord', 'battery life']
['service center', '"sales" team', 'tech guy']

还要注意所有 aspectTerms 都有一个 Term 属性；没有空的会产生 None.

编辑，受评论启发。

>>> from lxml import etree
>>> tree = etree.parse('Laptops_Train.xml')
>>> for sentence in tree.xpath('.//sentence'):
...     sentence.xpath('.//aspectTerm/@term')
... 
['cord', 'battery life']
[]
['service center', '"sales" team', 'tech guy']

Answer 2

所以解决方案是使用“.findall”而不是 .find。因为 '.findall' 选择了所有 children。我的解决方法如下：-

    def getAspect(sentences):
        aspectList = []
        reviewList = []
        text = sentence.find('text').text
        reviewList.append(text)
        for aspectTerms in sentence.iter('aspectTerms'):
            #for aspectTerm in aspectTerms.iter('aspectTerm'): 
            aspect = aspectTerms.findall('aspectTerm')#.get('term')
            for aspectElem in aspect:
                aspects = aspectElem.get('term')
                aspectList.append(aspects)
                print(aspects)
        return aspectList


    aspectList = []
    for sentences in root.iter('sentences'):
        for sentence in sentences.iter('sentence'):
            aspectList.append(getAspect(sentence))

使用 ElementTree 从 xml 标签获取所有 children

Get all the children from xml tag using ElementTree

xml

elementtree

python-3.x