如何解析多个子组的 XML 嵌套值

Question

我有一个很大的.xml 文件，其中的一部分如下所示：

<?xml version="1.0"?>
<data>
    <measData>
        <Mesurment Id="55">
            <granPeriod duration="1" endTime="2021-01-02"/>
            <repPeriod duration="1"/>
            <measTypes>73 74 574 75 35 36 </measTypes>
            <measValue measObj="Group1">
                <measResults>512 52.733 33.5 82 0 0 </measResults>
            </measValue>
            <measValue measObj="Group2">
                <measResults>512 78.175 50 119.5 0 0 </measResults>
            </measValue>
        </Mesurment>
    </measData>
</data>

我正在尝试从中解析出所需的数据并将其保存在 CSV 文件中。 我遇到的问题是，在 xml 文件中 <measTypes> 重复了一次，之后提到了 group1 和 Group2 的 <measTypes> 的值。 对于不同的<Mesurment Id>，它会有所不同，并且每个<measTypes> 报告的组值可能超过 10 个 问题出在这里，我不知道如何为一个measTypes 报告多个measResults 我有以下代码来获取值：

import xml.etree.ElementTree as ET
import pandas as pd
parsDict = dict()
tree = ET.parse('new.xml')
root = tree.getroot()

for itm in tree.iter():
    if (itm.tag.split('}')[-1] == 'Mesurment'):
        parsDict['Mesurment'] = [itm.attrib['Id']]
    if (itm.tag.split('}')[-1] == 'granPeriod'):
        parsDict['duration'] = [itm.attrib['duration']]
        parsDict['endTime'] = [itm.attrib['endTime']]
    if (itm.tag.split('}')[-1] == 'measTypes'):
        parsDict['CounterID'] = [itm.text]
    if (itm.tag.split('}')[-1] == 'measValue'):
        parsDict['measObj'] = [itm.attrib['measObj']]
    if (itm.tag.split('}')[-1] == 'measResults'):
        parsDict['value'] = [itm.text]
df2 = pd.DataFrame(parsDict)
df2.to_csv('123.csv',index=False)
print('finish')

结果如下

报告最新组 我想要的结果如下所示，需要能够扩展到多个组和测量 ID

Answer 1

使用BeautifulSoup 库可能更容易做到这一点。在使用它之前，您应该安装这些依赖项：

beautifulsoup4 = "4.9.3"
lxml = "^4.6.1"

from bs4 import BeautifulSoup, Tag

soup = BeautifulSoup("""
<?xml version="1.0"?>
<data>
    <measData>
        <Mesurment Id="55">
            <granPeriod duration="1" endTime="2021-01-02"/>
            <repPeriod duration="1"/>
            <measTypes>73 74 574 75 35 36 </measTypes>
            <measValue measObj="Group1">
                <measResults>512 52.733 33.5 82 0 0 </measResults>
            </measValue>
            <measValue measObj="Group2">
                <measResults>512 78.175 50 119.5 0 0 </measResults>
            </measValue>
        </Mesurment>
    </measData>
</data>
""", features="xml")

response = []

for tag in soup.data.measData:
    if not isinstance(tag, Tag):
        continue
    
    # please, update this dict with all the top level attributes you need
    data = {"duration": tag.granPeriod.attrs["duration"], }

    for measValue in tag:
        if not isinstance(measValue, Tag) or getattr(measValue, "measResults") is None:
            continue

        response.append({
            **data,
            "measObj": measValue.attrs["measObj"],
            "value": measValue.measResults.text
        })

print(response)

更新

使用你做的库，可以这样做：

import xml.etree.ElementTree as ET
import pandas as pd

tree = ET.parse('new.xml')
root = tree.getroot()

response = []

for mesurment in tree.iter("Mesurment"):
    granPeriod = next(
        it for it in mesurment if it.tag == "granPeriod"
    )
    measTypes = next(
        it for it in mesurment if it.tag == "measTypes"
    )
    measValues = [it for it in mesurment if it.tag == "measValue"]

    mesurment_data = {
        "Mesurment": mesurment.attrib["Id"],
        "duration": granPeriod.attrib["duration"],
        "endTime": granPeriod.attrib["endTime"],
        "CounterId": measTypes.text,
    }

    for value in measValues:
        response.append({
            **mesurment_data,
            "measObj": value.attrib["measObj"],
            "value": next(
                it.text for it in value if it.tag == "measResults"
            )
        })

df2 = pd.DataFrame(response)
print(df2)