lxml | 易学教程

lxml XMLSyntaxError: Namespace default prefix was not found

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问题 I am using lxml to read my xml file. I am using a code something like below. It works just fine with lxml2.3 beta1, but with lxml2.3 it gives me zn xml syntax error as shown below. I went through the release notes for both versions, but could not figure out what could have caused this error or how to fix it. Please help if you have come across such a thing or have any clues about it. Thanks!! Code: from lxml import etree def parseXml(context,attribList,elemList): for event, element in context

Python 与 html解析

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Python 与 html解析文章目录 Python 与 html解析正则表达式 RE in Python `match()` 修饰符 `search()` `findall()` XPath & LXML XPath常用规则导入 HTML 从字符串导入 HTML 从文件导入 HTML 获取节点获取所有节点获取所有指定标签获取子节点获取特定属性的节点获取父节点获取节点中的的文本获取属性补充 BeautifulSoup BeaufulSoup对象的初始化节点选择器选择标签嵌套选择关联选择获取**子孙节点** 获取父节点和祖先节点获取兄弟节点方法选择器 `find()` `findall()` 更多 CSS选择器提取信息获取完整标签获取标签类型获取标签内容获取属性 PyQuery 初始化字符串初始化 URL初始化 CSS选择器查找节点遍历获取信息 `attr()` 获取属性 `text()` 获取文本节点操作本文由 CDFMLR 原创，收录于个人主页 https://clownote.github.io ，并同时发布到 CSDN。本人不保证 CSDN 排版正确，敬请访问 clownote 以获得良好的阅读体验。正则表达式正则表达式是一种处理字符串的强大的工具，它有自己特定的语法结构，可以高效地实现字符串的检索、替换

代码小测试

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from bs4 import BeautifulSoup from lxml import html , etree file = 'hm.html' htmlfile = open ( file , 'r' , encoding = 'utf-8' ) htmlhandle = htmlfile . read ( ) soup = BeautifulSoup ( htmlhandle , features = 'lxml' ) #a=soup.text a = soup . find_all ( name = 'div' , attrs = { "class" : "p" } ) [ 0 ] . text #a = soup.select('') #print(a)#以上为内容爬取 #网页的url进行爬取 from bs4 import BeautifulSoup from lxml import html , etree file = 'hm.html' htmlfile = open ( file , 'r' , encoding = 'utf-8' ) htmlhandle = htmlfile . read ( ) soup = BeautifulSoup ( htmlhandle , features = 'lxml' ) #a = soup.find_all

初探python爬虫（四）——xpath

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在爬虫时可以使用xpath做相应的信息抽取 xpath常用规则表达式描述 nodename 选取此接待你的所有子节点 / 从当前节点选取直接子节点 // 从当前节点选取子孙节点 . 选取当前节点 … 选取当前子节点的父节点 @ 选取属性安装 cmd-》pip3 install lxml 实例 ##第一种方式，直接再python代码中解析html字符串 #导入lxml，下面两句话相当于from lxml import etree #只不过在python之后的lxml模块中不再能直接应仍有etree模块 from lxml import html etree = html.etree text=''' <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>表单验证01</title> </head> <body> <ul> <li><a href ="/a/b/c/java/" >java</a></li> <li><a href ="/a/b/c/python/" >python</a></li> <li><a href ="/a/b/c/ai/" >ai</a></li> </ul> </body> </html> ''' #使用etree解析html中的字符串 html = etree

Working with namespace while parsing XML using ElementTree

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问题 This is follow on question for Modify a XML using ElementTree I am now having namespaces in my XML and tried understanding the answer at Parsing XML with namespace in Python via 'ElementTree' and have the following. XML file. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <grandParent> <parent> <child>Sam/Astronaut</child> </parent> <

Python xpath query not returning text value

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问题 I am trying to scrape data from the following page using the lxml module in Python: http://www.thehindu.com/todays-paper/with-afspa-india-has-failed-statute-amnesty/article7376286.ece. I want to get the text in the first paragraph, but the following code is returning null value from lxml import html import requests page = requests.get('http://www.thehindu.com/todays-paper/with-afspa-india-has-failed-statute-amnesty/article7376286.ece') tree = html.fromstring(page.text) data = tree.xpath('//*[

Adding xml prefix declaration with lxml in python

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问题 Short version : How to add the xmlns:xi="http://www.w3.org/2001/XInclude" prefix decleration to my root element in python with lxml ? Context : I have some XML files that include IDs to other files. These IDs represent the referenced file names. Using lxml I managed to replace these with the appropriate XInclude statement, but if I do not have the prefix decleration my my XML parser won't add the includes, which is normal. Edit : I won't include my code because it won't help at understanding

beautifulsoup4进阶学习笔记

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**requests库是可以找到想要的东西，基本上几行代码就搞定，但是进一步把有用的内容提取出来变成自己想要的格式来方便后续进行数据分析## 正则表达式提取的话，需要一些时间成本，这个可以每天积累一点。这里我直接看的官方文档安装解析器 BeautifulSoup支持python标准库中的html解析器，还支持一些第三方的解析器，有一个很不错的是lxml win系统 pip install lxml 来源： https://www.cnblogs.com/gaowenxingxing/p/12259825.html

python爬虫框架之scrapy安装记

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火柴人大战scrapy 一、Windows安装Scrapy框架一、Windows安装Scrapy框架安装lxml解析库 pip3 install lxml 安装依赖包pyOpenSSL 在官方网站下载 wheel 文件（详见 https://pypi.python.org/pypi/pyOpenSSL#downloads）即可 pip3 install pyOpenSSL - 17.2 .0 - py2 . py3 - none - any . whl （要执行命令要选择依赖放入的目录）安装PyWin32 依赖包链接： https://sourceforge.net/projects/pywin32/files/pywin32/Build%20221/ 入坑记：选择对应python时下载的位数下载对应PyWin32对应的位数安装包，安装成功后如果下一步报version required啥的，就说明位数或者版本没有对应上，下一步自动抓取不到python文件的位置。安装Scrapy pip3 install Scrapy （这里的一切运行报错都有可能是因为你缺少依赖包）验证Scrapy是否安装成功输入 scrapy 即可来源： CSDN 作者： MatchstickMen_roukun 链接： https://blog.csdn.net/qq_43264377

网络爬虫之数据解析

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网络爬虫之数据解析 XPath与lxml库 XPath基本语法使用方式注意事项 BeautifulSoup4库正则表达式和re模块解析工具对比 XPath与lxml库 XPath基本语法 1、选取结点 2、谓语 3、通配符使用方式 XPath使用方式：使用 // 获取整个页面当中的元素，然后写标签名，然后再写谓语进行提取 # 使用lxml库解析HTML代码： # 1、解析HTML字符串 html = etree . HTML ( text ) # 2、解析HTML文件 # 指定解析器，默认为XML解析器 parser = etree . HTMLParser ( encoding = 'utf-8' ) html = etree . parse ( "index.html" , parser = parser ) # 1、获取所有tr标签 trs = html . xpath ( "//tr" ) # 2、获取第二个tr标签 trs = html . xpath ( "//tr[2]" ) # 3、获取所有class等于even的tr标签 trs = html . xpath ( "//tr[@class='even']" ) # 4、获取所有a标签的href属性 a = html . xpath ( "//a/@href" ) 注意事项 BeautifulSoup4库

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