python3使用sax操作xml

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python使用SAX解析xml
SAX是一种基于事件驱动的API。
利用SAX解析XML文档牵涉到两个部分:解析器和事件处理器。
解析器负责读取XML文档,并向事件处理器发送事件,如元素开始跟元素结束事件;
而事件处理器则负责对事件作出相应,对传递的XML数据进行处理。
1、对大型文件进行处理；
2、只需要文件的部分内容，或者只需从文件中得到特定信息。
3、想建立自己的对象模型的时候。
在python中使用sax方式处理xml要先引入xml.sax中的parse函数，还有xml.sax.handler中的ContentHandler。

test.py

#!/usr/bin/python3import xml.saxclass MovieHandler( xml.sax.ContentHandler ):   def __init__(self):      self.CurrentData = ""      self.type = ""      self.format = ""      self.year = ""      self.rating = ""      self.stars = ""      self.description = ""   # 元素开始调用   def startElement(self, tag, attributes):      self.CurrentData = tag      if tag == "movie":         print ("*****Movie*****")         title = attributes["title"]         print ("Title:", title)   # 元素结束调用   def endElement(self, tag):      if self.CurrentData == "type":         print ("Type:", self.type)      elif self.CurrentData == "format":         print ("Format:", self.format)      elif self.CurrentData == "year":         print ("Year:", self.year)      elif self.CurrentData == "rating":         print ("Rating:", self.rating)      elif self.CurrentData == "stars":         print ("Stars:", self.stars)      elif self.CurrentData == "description":         print ("Description:", self.description)      self.CurrentData = ""   # 读取字符时调用   def characters(self, content):      if self.CurrentData == "type":         self.type = content      elif self.CurrentData == "format":         self.format = content      elif self.CurrentData == "year":         self.year = content      elif self.CurrentData == "rating":         self.rating = content      elif self.CurrentData == "stars":         self.stars = content      elif self.CurrentData == "description":         self.description = content  if ( __name__ == "__main__"):      # 创建一个 XMLReader   parser = xml.sax.make_parser()   # turn off namepsaces   parser.setFeature(xml.sax.handler.feature_namespaces, 0)   # 重写 ContextHandler   Handler = MovieHandler()   parser.setContentHandler( Handler )      parser.parse("movies.xml")

执行结果

[root@mail pythonCode]# python3 test.py*****Movie*****Title: Enemy BehindType: love中国Format: DVDYear: 2003Rating: PGStars: 10Description: Talk about a US-Japan war*****Movie*****Title: TransformersType: Anime, Science FictionFormat: DVDYear: 1989Rating: RStars: 8Description: A schientific fiction

movies.xml内容

<?xml version="1.0" encoding="utf-8"?><collection shelf="New Arrivals"><movie title="Enemy Behind">   <type>love中国</type>   <format>DVD</format>   <year>2003</year>   <rating>PG</rating>   <stars>10</stars>   <description>Talk about a US-Japan war</description></movie><movie title="Transformers">   <type>Anime, Science Fiction</type>   <format>DVD</format>   <year>1989</year>   <rating>R</rating>   <stars>8</stars>   <description>A schientific fiction</description></movie></collection>

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