#!/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):
  '''讀取并解析xml文件
    in_path: xml路徑
    return: ElementTree'''
  tree = ElementTree()
  tree.parse(in_path)
  return tree

def write_xml(tree, out_path):
  '''將xml文件寫出
    tree: xml樹
    out_path: 寫出路徑'''
  tree.write(out_path, encoding="utf-8",xml_declaration=True)

def if_match(node, kv_map):
  '''判斷某個節點是否包含所有傳入參數屬性
    node: 節點
    kv_map: 屬性及屬性值組成的map'''
  for key in kv_map:
    if node.get(key) != kv_map.get(key):
      return False
  return True

#---------------search -----
def find_nodes(tree, path):
  '''查找某個路徑匹配的所有節點
    tree: xml樹
    path: 節點路徑'''
  return tree.findall(path)

def get_node_by_keyvalue(nodelist, kv_map):
  '''根據屬性及屬性值定位符合的節點，返回節點
    nodelist: 節點列表
    kv_map: 匹配屬性及屬性值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 /刪除 節點的屬性及屬性值
    nodelist: 節點列表
    kv_map:屬性及屬性值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):
  '''改變/增加/刪除一個節點的文本
    nodelist:節點列表
    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):
  '''新造一個節點
    tag:節點標簽
    property_map:屬性及屬性值map
    content: 節點閉合標簽里的文本內容
    return 新節點'''
  element = Element(tag, property_map)
  element.text = content
  return element

def add_child_node(nodelist, element):
  '''給一個節點添加子節點
    nodelist: 節點列表
    element: 子節點'''
  for node in nodelist:
    node.append(element)

def del_node_by_tagkeyvalue(nodelist, tag, kv_map):
  '''同過屬性及屬性值定位一個節點，并刪除之
    nodelist: 父節點列表
    tag:子節點標簽
    kv_map: 屬性及屬性值列表'''
  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. 讀取xml文件
  tree = read_xml("./test.xml")

  #2. 屬性修改
   #A. 找到父節點
  nodes = find_nodes(tree, "processers/processer")
   #B. 通過屬性準確定位子節點
  result_nodes = get_node_by_keyvalue(nodes, {"name":"BProcesser"})
   #C. 修改節點屬性
  change_node_properties(result_nodes, {"age": "1"})
   #D. 刪除節點屬性
  change_node_properties(result_nodes, {"value":""}, True)

  #3. 節點修改
   #A.新建節點
  a = create_node("person", {"age":"15","money":"200000"}, "this is the firest content")
   #B.插入到父節點之下
  add_child_node(result_nodes, a)

  #4. 刪除節點
    #定位父節點
  del_parent_nodes = find_nodes(tree, "processers/services/service")
    #準確定位子節點并刪除之
  target_del_node = del_node_by_tagkeyvalue(del_parent_nodes, "chain", {"sequency" : "chain1"})

  #5. 修改節點文本
    #定位節點
  text_nodes = get_node_by_keyvalue(find_nodes(tree, "processers/services/service/chain"), {"sequency":"chain3"})
  change_node_text(text_nodes, "new text")

  #6. 輸出到結果文件
  write_xml(tree, "./out.xml")


          

            
              
                
                
                
                  
                    this is the firest content
                  
                
                
                  
                    this is the firest content
                  
                
                
                  
                    
                  
                  
                    
                      new text