Python XML attributes/node/text additions and deletions [Xml.etree.elementtree]__python

http://blog.csdn.net/wklken/article/details/7603071

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Demand:

In practical application, the XML configuration file needs to be modified in real time.

1. Add and remove certain nodes

2. Add, delete, modify some properties under a node

3. Add, delete, modify the text of some nodes

XML source file format [Example][HTML] View Plain copy print? <?xml version= "1.0"  encoding= "UTF-8"?>   <framework>        <processers>           <processer  Name= "Aprocesser"  file= "lib64/a.so"                 path= "/tmp" >           </processer >           <processer name= "Bprocesser"  file = "lib64/b.so"  value= "Fordelete" >           </ processer>           <processer name= "BProcesser"  file= "lib64/b.so2222222"/>                      <services>       &nbsP;       <service name= "Search"  prefix= "/bin/search?"                     Output_formatter= "Outputformatter:service_inc" >                                        <chain sequency= "Chain1"/>                    <chain sequency= " Chain2 "></chain>                </service>               < Service name= "Update"  prefix= "/bin/update?" >                   <chain sequency= "chain3"  value= "Fordelete"/>                </service>            </services>       </processers>    </framework>  
Working with libraries:

Xml.etree.ElementTree

Official Document Address: http://docs.python.org/library/xml.etree.elementtree.html

To realize the idea:

Using ElementTree, first read the file into, parse into a tree, then, according to the path, you can navigate to each node of the tree, and then modify the node, and finally directly to the output

Code attached to the document:[Python] View Plain copy print? #!/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):        "" Read and parse XML files           in_path: xml path          return: elementtree ' "        tree = elementtree ()         Tree.parse (In_path)        return tree      Def write_ XML (Tree, out_path):        ' "" Write XML file           tree: xml Tree          out_path:  write path '        tree.write (out_path, encoding= "Utf-8", Xml_declaration=true)       Def if_match (node, kv_map):        "" to determine whether a node contains all incoming parameter properties          node:  node           kv_map:  attribute and attribute value of Map ' '        for key in kv_map:           if node.get (Key)  != kv_map.get (key):                return False       return True      #---------------search -----      def find_nodes (tree, path):        "" To find all nodes that match a path          tree: xml Tree          path:   Node path ''        return tree.findall (path)          def  get_node_by_keyvalue (nodelist, kv_map):        "' locates nodes according to attributes and attribute values, Back to Node          nodelist:  node list           kv_map:  matching attributes and attribute values 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):        ' Modify/Add  / Delete   node's genusSex and attribute values          nodelist:  node list           kv_map: Attributes and property values 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):        "' Change/Add/delete text       for a node     nodelist: Node list          text :  updated text ' '        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):        ' ' new node          tag: Node tags          property_map: Attributes and property values map          content:  node closed label text content          return  new node '         element = element (tag, property_map)         element.text = content       return element               Def add_child_node (nodelist,  Element):        "' Add child nodes to a node           nodelist:  Node List          element:  sub node '         for node in nodelist:           node.append ( Element)               Def del_node_by_ Tagkeyvalue (nodelist, tag, kv_map):        ' "" to locate a node and remove it from the same property and property values          nodelist:  parent Node list           tag: Sub-node tags          kv_map:  attributes and attribute values list '         for parent_node in nodelist:            children = parent_node.getchildren ()             for child in children:                if child.tag == tag and if_match (Child, kv_map):    &NBSP;&NBSP;&NBSP;&NBSP;            parent_node.remove (Child)                                       if __name__ ==  "_ _main__ ":               #1 .  read XML file        tree = read_xml ("./test.xml")                 #2 .  Property modification           #A .  Find parent node        nodes = find_nodes (tree,  "Processers/processer")            #B .  to locate child nodes accurately via attributes        result_nodes  = get_node_by_keyvalue (nodes, {"name": "Bprocesser"})            #C .  Modify NodesProperties        change_node_properties (result_nodes, {"Age":  "1"})           #D .  Delete node properties        change_node_properties ( result_nodes, {"value": "}, true"                 #3 .  node modification           #A. New node         A = create_node ("Person",  {"age": "The", "money": "200000"},  "this is the  Firest content ")           #B. Insert under parent node         add_child_node (result_nodes, a)                 #4 .  Delete node            #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 .  Modify node text             #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 .  Output to the result file        write_xml (tree,  "./out.xml")              

Result file after main processing: [HTML] view plain copy print? <?xml version= ' 1.0 ' encoding= ' utf-8 '?> <framework> <processers> <processer file= ' Li  B64/a.so "Name=" Aprocesser "path="/tmp "> </processer> <processer age=" 1 "file=" lib64/b.so " Name= "Bprocesser" > <person age= "money=" 200000 ">this is the Firest content</person>