使用lxml，如何读取嵌套元素中的文本？

Question

我正在尝试搜索约500个XML文档中的某些特定短语，并输出包含任何这些短语的任何元素的ID。 目前，这是我的代码：

from lxml import etree
import os
import re

files = os.listdir('C:/Users/Me/Desktop/xml')
search_words = ['House divided', 'Committee divided', 'on Division', 'Division List',
                'The Ayes and the Noes',]

for f in files:
    doc = etree.parse('C:/Users/Me/Desktop/xml/' +f)
    for elem in doc.iter():
        for word in search_words:
            if elem.text is not None and str(elem.attrib) != "{}" and word in elem.text and len(re.findall(r'\d+', elem.text))>1:
                votes = re.findall(r'\d+', elem.text)
                string = str(elem.attrib)[8:-2] + ","
                string += (str(votes[0]) + "," + str(votes[1]) + ",")
                string += word + ","
                string += str(elem.sourceline)
                print string      

这样的输入将正确输出：

<p id="S3V0001P0-01869">The House divided; Against the Motion 83; For it 23&#x2014;Majority 60.</p>

但是将缺少带有这样的嵌套元素的输入，因为内部文本没有针对以下短语进行解析：

<p id="S3V0141P0-01248"><member>THE CHANCELLOR OF THE EXCHEQUER</member><membercontribution> said, that the precedent occurred on the 8th of April, 1850, on a Motion for going into a Committee of Supply. An Amendment was moved by Captain Boldero on the subject of assistant-surgeons in the navy, when, on a division being called for, the Question was put that the words proposed to be left out stand part of the Question. The House divided, when the numbers were&#x2014;Ayes, 40; Noes, 48. The Question, "That the proposed words be added" was put and agreed to; the main Question, as amended, was put and agreed to; and the Question being then put, "That Mr. Speaker do now leave the chair," that Motion was agreed to, and the House went into Committee of Supply.</membercontribution></p>

有没有办法读取这样的嵌套元素中的文本并返回其ID？

Answer 1

使用lxml，有一个xpath方法，XPath有一个contains功能，可以与例如一起使用

doc = ET.fromstring('<p id="S3V0141P0-01248"><member>THE CHANCELLOR OF THE EXCHEQUER</member><membercontribution> said, that the precedent occurred on the 8th of April, 1850, on a Motion for going into a Committee of Supply. An Amendment was moved by Captain Boldero on the subject of assistant-surgeons in the navy, when, on a division being called for, the Question was put that the words proposed to be left out stand part of the Question. The House divided, when the numbers were&#x2014;Ayes, 40; Noes, 48. The Question, "That the proposed words be added" was put and agreed to; the main Question, as amended, was put and agreed to; and the Question being then put, "That Mr. Speaker do now leave the chair," that Motion was agreed to, and the House went into Committee of Supply.</membercontribution></p>')
result = doc.xpath('//*[@id and contains(., $word)]', word = 'House divided')

Answer 2

您可以使用一些XPath并提取所有有趣的内容下面的所有文本元素。 我喜欢Parsel ： pip install parsel 。

import parsel

data = ('<x><y><z><p id="S3V0141P0-01248"><member>THE CHANCELLOR OF THE EXCHEQUER'
        '</member><membercontribution> said, that the precedent occurred on the '
        '8th of April, 1850, on a Motion ...</membercontribution></p></z></y></x>')

selector = parsel.Selector(data)

for para in selector.xpath('//p'):
    id = para.xpath('@id').extract_first()
    texts = para.xpath('*/text()').extract()
    for text in texts:
        # do whatever search
        print(id, len(text), 'April' in text)

输出：

S3V0141P0-01248 31 False
S3V0141P0-01248 77 True