使用python自带的xml.dom创建和解析xml

时间:2022-08-24 22:38:54

    python中的xml.dom模块使用的就是传统的dom解析api和方法。所以也就不写什么了,主要就是练习敲敲代码,继续熟悉python。本文通过xml.dom.minidom创建一个xml文档,然后再解析出来,用以熟悉相关接口方法的使用。

创建一个xml文档:

'''
Created on 2012-1-10
Create a xml document
@author: xiaojay
'''

from xml.dom import minidom

doc = minidom.Document()
doc.appendChild(doc.createComment("This is a simple xml."))
booklist = doc.createElement("booklist")
doc.appendChild(booklist)

def addBook(newbook):
book = doc.createElement("book")
book.setAttribute("id", newbook["id"])

title = doc.createElement("title")
title.appendChild(doc.createTextNode(newbook["title"]))
book.appendChild(title)

author = doc.createElement("author")
name = doc.createElement("name")
firstname = doc.createElement("firstname")
firstname.appendChild(doc.createTextNode(newbook["firstname"]))
lastname = doc.createElement("lastname")
lastname.appendChild(doc.createTextNode(newbook["lastname"]))
name.appendChild(firstname)
name.appendChild(lastname)
author.appendChild(name)
book.appendChild(author)

pubdate = doc.createElement("pubdate")
pubdate.appendChild(doc.createTextNode(newbook["pubdate"]))
book.appendChild(pubdate)

booklist.appendChild(book)

addBook({"id":"1001","title":"An apple","firstname":"Peter","lastname":"Zhang","pubdate":"2012-1-12"})
addBook({"id":"1002","title":"Love","firstname":"Mike","lastname":"Li","pubdate":"2012-1-10"})
addBook({"id":"1003","title":"Steve.Jobs","firstname":"Tom","lastname":"Wang","pubdate":"2012-1-19"})
addBook({"id":"1004","title":"Harry Potter","firstname":"Peter","lastname":"Chen","pubdate":"2012-11-11"})

f = file("book.xml","w")
doc.writexml(f)
f.close()

  通过doc.toprettyxml(indent, newl, encoding)方法可以优雅显示xml文档,但是要避免直接写入文本,否则会给解析带来麻烦,尽量使用自带的writexml方法。

生成的文档内容:

<?xml version="1.0" ?>
<!--This is a simple xml.-->
<booklist>
  <book id="1001">
    <title>
    An apple
    </title>
  <author>
    <name>
      <firstname>
      Peter
      </firstname>
      <lastname>
      Zhang
      </lastname>
    </name>
  </author>
  <pubdate>
  2012-1-12
  </pubdate>
  </book>

 .................
</booklist>

 

解析该xml文档:

'''
Created on 2012-1-10
Scan a xml doc
@author: xiaojay
'''

from xml.dom import minidom , Node

class bookscanner:
def __init__(self,doc):
for child in doc.childNodes :
if child.nodeType == Node.ELEMENT_NODE \
and child.tagName == "book" :
bookid = child.getAttribute("id")
print "*"*20
print "Book id : " , bookid
self.handle_book(child)

def handle_book(self,node):
for child in node.childNodes :
if child.nodeType == Node.ELEMENT_NODE :
if child.tagName == "title":
print "Title : " , self.getText(child.firstChild)
if child.tagName == "author":
self.handle_author(child)
if child.tagName == "pubdate":
print "Pubdate : " , self.getText(child.firstChild)

def getText(self,node):
if node.nodeType == Node.TEXT_NODE :
return node.nodeValue
else: return ""

def handle_author(self,node):
author = node.firstChild
for child in author.childNodes:
if child.nodeType == Node.ELEMENT_NODE:
if child.tagName == "firstname" :
print "Firstname : ", self.getText(child.firstChild)
if child.tagName == "lastname" :
print "Lastname : " , self.getText(child.firstChild)


doc = minidom.parse("book.xml")
for child in doc.childNodes :
if child.nodeType == Node.COMMENT_NODE:
print "Conment : " , child.nodeValue
if child.nodeType == Node.ELEMENT_NODE:
bookscanner(child)

  

输出结果:

Conment : This is a simple xml.
********************
Book id : 1001
Title : An apple
Firstname : Peter
Lastname : Zhang
Pubdate : 2012-1-12
********************
Book id : 1002
Title : Love
Firstname : Mike
Lastname : Li
Pubdate : 2012-1-10
********************
Book id : 1003
Title : Steve.Jobs
Firstname : Tom
Lastname : Wang
Pubdate : 2012-1-19
********************
Book id : 1004
Title : Harry Potter
Firstname : Peter
Lastname : Chen
Pubdate : 2012-11-11