在python中解析XML文件也有Dom和Sax两种方式,这里先介绍如何是使用Dom解析XML,这一篇文章是Dom生成XML文件,下一篇文章再继续介绍Dom解析XML文件。
在生成XML文件中,我们主要使用下面的方法来完成。
主要方法
1、生成XML节点(node)
Python代码
- createElement("node_name")
2、给节点添加属性值(Attribute)
Python代码
- node.setAttribute("att_name", "arr_value")
3、节点的标签值(data)
Python代码
- createTextNode("node_value")
其中第1、3点在创建完节点(节点值)之后,还需使用下面的方法添加到指点的节点的位置下面:
Python代码
- prev_node.appendChild(cur_node)
这里的prev_node要添加节点的上一层节点,而cur_node即为当前要添加的节点了。
代码演示
下面用代码来演示下如何使用Dom来生成XML,这个是简单版本,如下:
Python代码
- '''
- Created on 2012-8-28
- @author: walfred
- @module: domxml.genXML
- @description:
- '''
- import xml.dom.minidom as Dom
- if __name__ == "__main__":
- doc = Dom.Document()
- root_node = doc.createElement("book_store")
- root_node.setAttribute("name", "newhua")
- root_node.setAttribute("website", "http://www.ourunix.org")
- doc.appendChild(root_node)
- book_node = doc.createElement("book1")
- book_name_node = doc.createElement("name")
- book_name_value = doc.createTextNode("hamlet")
- book_name_node.appendChild(book_name_value)
- book_node.appendChild(book_name_node)
- book_author_node = doc.createElement("author")
- book_author_value = doc.createTextNode("William Shakespeare")
- book_author_node.appendChild(book_author_value)
- book_node.appendChild(book_author_node)
- root_node.appendChild(book_node)
- f = open("book_store.xml", "w")
- f.write(doc.toprettyxml(indent = "\t", newl = "\n", encoding = "utf-8"))
- f.close()
这个代码将在当前目录下生成一个book_store.xml文件,我把它也贴在下面:
XML/HTML代码
- <?xml version="1.0" encoding="utf-8"?>
- <book_store name="newhua" website="http://www.ourunix.org">
- <book1>
- <name>hamlet</name>
- <author>William Shakespeare</author>
- </book1>
- </book_store>
当然一旦你掌握了这些基本方法之后,我们可以用一个类来更好的完成,这个类我们称之为XMLGenerator,代码如下:
Python代码
- '''
- Created on 2012-8-28
- @author: walfred
- @module: domxml.wXMLbyDom
- @description:
- '''
- import xml.dom.minidom as Dom
- class XMLGenerator:
- def __init__(self, xml_name):
- self.doc = Dom.Document()
- self.xml_name = xml_name
- def createNode(self, node_name):
- return self.doc.createElement(node_name)
- def addNode(self, node, prev_node = None):
- cur_node = node
- if prev_node is not None:
- prev_node.appendChild(cur_node)
- else:
- self.doc.appendChild(cur_node)
- return cur_node
- def setNodeAttr(self, node, att_name, value):
- cur_node = node
- cur_node.setAttribute(att_name, value)
- def setNodeValue(self, cur_node, value):
- node_data = self.doc.createTextNode(value)
- cur_node.appendChild(node_data)
- def genXml(self):
- f = open(self.xml_name, "w")
- f.write(self.doc.toprettyxml(indent = "\t", newl = "\n", encoding = "utf-8"))
- f.close()
- if __name__ == "__main__":
- myXMLGenerator = XMLGenerator("book_store.xml")
- #xml root node
- node_book_store = myXMLGenerator.createNode("book_store")
- myXMLGenerator.setNodeAttr(node_book_store, "name", "new hua")
- myXMLGenerator.setNodeAttr(node_book_store, "website", "http://www.ourunix.org")
- myXMLGenerator.addNode(node = node_book_store)
- #book01
- node_book_01 = myXMLGenerator.createNode("book")
- node_book_01_name = myXMLGenerator.createNode("name")
- myXMLGenerator.setNodeValue(node_book_01_name, "Hamlet")
- myXMLGenerator.addNode(node_book_01_name, node_book_01)
- node_book_01_author = myXMLGenerator.createNode("author")
- myXMLGenerator.setNodeValue(node_book_01_author, "William Shakespeare")
- myXMLGenerator.addNode(node_book_01_author, node_book_01)
- node_book_01_price = myXMLGenerator.createNode("price")
- myXMLGenerator.setNodeValue(node_book_01_price, "$20")
- myXMLGenerator.addNode(node_book_01_price, node_book_01)
- node_book_01_grade = myXMLGenerator.createNode("grade")
- myXMLGenerator.setNodeValue(node_book_01_grade, "good")
- myXMLGenerator.addNode(node_book_01_grade, node_book_01)
- myXMLGenerator.addNode(node_book_01, node_book_store)
- #book 02
- node_book_02 = myXMLGenerator.createNode("book")
- node_book_02_name = myXMLGenerator.createNode("name")
- myXMLGenerator.setNodeValue(node_book_02_name, "shuihu")
- myXMLGenerator.addNode(node_book_02_name, node_book_02)
- node_book_02_author = myXMLGenerator.createNode("author")
- myXMLGenerator.setNodeValue(node_book_02_author, "naian shi")
- myXMLGenerator.addNode(node_book_02_author, node_book_02)
- node_book_02_price = myXMLGenerator.createNode("price")
- myXMLGenerator.setNodeValue(node_book_02_price, "$200")
- myXMLGenerator.addNode(node_book_02_price, node_book_02)
- node_book_02_grade = myXMLGenerator.createNode("grade")
- myXMLGenerator.setNodeValue(node_book_02_grade, "good")
- myXMLGenerator.addNode(node_book_02_grade, node_book_02)
- myXMLGenerator.addNode(node_book_02, node_book_store)
- #gen
- myXMLGenerator.genXml()
同样这个方法会在本目录下生成一个book_store.xml文件,如下:
XML/HTML代码
- <?xml version="1.0" encoding="utf-8"?>
- <book_store name="new hua" website="http://www.ourunix.org">
- <book>
- <name>Hamlet</name>
- <author>William Shakespeare</author>
- <price>$20</price>
- <grade>good</grade>
- </book>
- <book>
- <name>shuihu</name>
- <author>naian shi</author>
- <price>$200</price>
- <grade>good</grade>
- </book>
- </book_store>
这个版本算一个稍微高级的版本,但由于时间有限还很显得粗糙,读者可以发挥出更好的。