详解在Python程序中解析并修改XML内容的方法

<?xml version="1.0" encoding="UTF-8"?>

 
 
 
 
 
 

 
 

 
 
 
 
 
 
 
 

#!/usr/bin/python
# -*- coding=utf-8 -*-
# author : wklken@yeah.net
# date: 2012-05-25
# version: 0.1

from xml.etree.ElementTree import ElementTree,Element

def read_xml(in_path):
 '''读取并解析xml文件
 in_path: xml路径
 return: ElementTree'''
 tree = ElementTree()
 tree.parse(in_path)
 return tree

def write_xml(tree, out_path):
 '''将xml文件写出
 tree: xml树
 out_path: 写出路径'''
 tree.write(out_path, encoding="utf-8",xml_declaration=True)

def if_match(node, kv_map):
 '''判断某个节点是否包含所有传入参数属性
 node: 节点
 kv_map: 属性及属性值组成的map'''
 for key in kv_map:
 if node.get(key) != kv_map.get(key):
 return False
 return True

#---------------search -----
def find_nodes(tree, path):
 '''查找某个路径匹配的所有节点
 tree: xml树
 path: 节点路径'''
 return tree.findall(path)

def get_node_by_keyvalue(nodelist, kv_map):
 '''根据属性及属性值定位符合的节点，返回节点
 nodelist: 节点列表
 kv_map: 匹配属性及属性值map'''
 result_nodes = []
 for node in nodelist:
 if if_match(node, kv_map):
 result_nodes.append(node)
 return result_nodes

#---------------change -----
def change_node_properties(nodelist, kv_map, is_delete=False):
 '''修改/增加 /删除 节点的属性及属性值
 nodelist: 节点列表
 kv_map:属性及属性值map'''
 for node in nodelist:
 for key in kv_map:
 if is_delete:
 if key in node.attrib:
 del node.attrib[key]
 else:
 node.set(key, kv_map.get(key))

def change_node_text(nodelist, text, is_add=False, is_delete=False):
 '''改变/增加/删除一个节点的文本
 nodelist:节点列表
 text : 更新后的文本'''
 for node in nodelist:
 if is_add:
 node.text += text
 elif is_delete:
 node.text = ""
 else:
 node.text = text

def create_node(tag, property_map, content):
 '''新造一个节点
 tag:节点标签
 property_map:属性及属性值map
 content: 节点闭合标签里的文本内容
 return 新节点'''
 element = Element(tag, property_map)
 element.text = content
 return element

def add_child_node(nodelist, element):
 '''给一个节点添加子节点
 nodelist: 节点列表
 element: 子节点'''
 for node in nodelist:
 node.append(element)

def del_node_by_tagkeyvalue(nodelist, tag, kv_map):
 '''同过属性及属性值定位一个节点，并删除之
 nodelist: 父节点列表
 tag:子节点标签
 kv_map: 属性及属性值列表'''
 for parent_node in nodelist:
 children = parent_node.getchildren()
 for child in children:
 if child.tag == tag and if_match(child, kv_map):
 parent_node.remove(child)

if __name__ == "__main__":
 #1. 读取xml文件
 tree = read_xml("./test.xml")

 #2. 属性修改
 #A. 找到父节点
 nodes = find_nodes(tree, "processers/processer")
 #B. 通过属性准确定位子节点
 result_nodes = get_node_by_keyvalue(nodes, {"name":"BProcesser"})
 #C. 修改节点属性
 change_node_properties(result_nodes, {"age": "1"})
 #D. 删除节点属性
 change_node_properties(result_nodes, {"value":""}, True)

 #3. 节点修改
 #A.新建节点
 a = create_node("person", {"age":"15","money":"200000"}, "this is the firest content")
 #B.插入到父节点之下
 add_child_node(result_nodes, a)

 #4. 删除节点
 #定位父节点
 del_parent_nodes = find_nodes(tree, "processers/services/service")
 #准确定位子节点并删除之
 target_del_node = del_node_by_tagkeyvalue(del_parent_nodes, "chain", {"sequency" : "chain1"})

 #5. 修改节点文本
 #定位节点
 text_nodes = get_node_by_keyvalue(find_nodes(tree, "processers/services/service/chain"), {"sequency":"chain3"})
 change_node_text(text_nodes, "new text")

 #6. 

<?xml version='1.0' encoding='utf-8'?>

 
 
 
 
 this is the firest content
 
 
 this is the firest content
 

 
 

 
 
 
 new text