python 中xml解析有很多种方式，本文采用ElementTree方式对xml进行解析。以下代码是对一个xml文档中具体属性值进行修改的例子（会涉及到遍历xml文本），修改的界面如下：
实际修改的代码如下：
import xml.etree.ElementTree as ET
import json
import os
import sys
data_id = 1
tree = ET.ElementTree()
class XmlEdit:
def __init__(self):
pass
#遍历xml节点
def through_xml_data(self, root_node, level, result_list):
global data_id
temp_list = [data_id, level, root_node.tag, root_node.attrib]
result_list.append(temp_list)
data_id += 1
children_node = root_node.getchildren()
if len(children_node) == 0:
return
for child in children_node:
self.through_xml_data(child, level + 1, result_list)
return
def get_xml_file(self, in_file_path):
if os.path.exists(in_file_path):
print "xml file:" + in_file_path + " exit"
root = ET.parse(in_file_path).getroot()
level = 1
result_list = []
self.through_xml_data(root, level, result_list)
return result_list
else:
print "xml file" + in_file_path + " no exit"
return []
def get_isdbt_same_attr_positon(self, key, result_list):
# layer对应在result_list中的位置
map_dict = {"layer1": 3, "Layer1": 3,
"layer2": 4, "Layer2": 4,
"layer3": 5, "Layer5": 5,
"layera": 7, "layerA": 7,
"layerb": 8, "layerB": 8,
"layerc": 9, "layerC":9}
if key in map_dict.keys():
position = map_dict[key]
result = result_list[position]
return True, result, position
else:
return False, " ", 0
# 修改xml项值,默认一个值，只有当tag_name = layer时，修改该参数
def update_xml_data(self, root, tag_name, attrib_name, value, flag = 9):
if tag_name == "Layer":
find_num = 0
# 当tag_name 是Layer（会全部修改），以后再实现
for child in root.iter(tag_name):
find_num += 1
if find_num == flag:
child.attrib[attrib_name] = value
print "update xml config:" + attrib_name + " of " + tag_name
else:
for child in root.iter(tag_name):
child.attrib[attrib_name] = value
print "update xml config:" + attrib_name + " of " + tag_name
#解析配置文件
def load_xml_edit_config(self, filepath):
if os.path.exists(filepath):
with open(filepath, 'r') as f:
xml_config = json.load(f)
return xml_config
else:
print "error:" + filepath + ' no exit'
return
# 解析配置文件字典，获取想要编译的xml,xml_file_name为文件名，xml_config为整个配置文件
def parse_xml_config(self, xml_file_name, xml_config):
if xml_file_name in xml_config.keys():
xml_config_data = xml_config[xml_file_name]
print "edit:" + xml_file_name
return True, xml_config_data
else:
print "error:" + xml_file_name + " no exit"
return False, {}
# 判断ts_config_data中的key是否在xml中，存在的话，修改值，并输出xml配置文档，码流机打开新配置文件
def exist_and_replace(self, xml_config_data, root, ret_list, f_type='t2'):
for key in xml_config_data.keys():
flag = False
if f_type == "isdbt":
ret, result, position = self.get_isdbt_same_attr_positon(key, ret_list)
if ret:
flag = True
same_attr_dict = xml_config_data[key]
layer_dict = {3: 1, 4: 2, 5: 3}
# 处于layer1-3
if position in [3, 4, 5]:
for same_attr_key in same_attr_dict.keys():
same_attr_key_flag = False
if same_attr_key in result[3].keys():
same_attr_key_flag = True
self.update_xml_data(root, result[2], same_attr_key, same_attr_dict[same_attr_key], layer_dict[position])
if not same_attr_key_flag:
print same_attr_key + " no exit in config file"
else:
for same_attr_key in same_attr_dict.keys():
same_attr_key_flag = False
if same_attr_key in result[3].keys():
same_attr_key_flag = True
self.update_xml_data(root, result[2], same_attr_key, same_attr_dict[same_attr_key])
if not same_attr_key_flag:
print same_attr_key + " no exit in config file"
# 不处于Layer1-3,Layer:a-c
else:
for result in ret_list:
if key in result[3].keys():
flag = True
self.update_xml_data(root, result[2], key, xml_config_data[key])
else:
for result in ret_list:
if key in result[3].keys():
flag = True
self.update_xml_data(root, result[2], key, xml_config_data[key])
# 如果没匹配到，输出如下：
if not flag:
print "error:" + key + " no exists in xml config"
'''
# 单个配置名修改
def set_xml_config(ts_type, xml_path):
exit_flag = False
if ts_type in ["t2", "isdbt"]:
xml_file_path = r"./config/" + ts_type + ".json"
else:
print ts_type + "error"
sys.exit(2)
# 获取配置文件
xml_config = load_xml_edit_config(xml_file_path)
exist_and_replace(xml_config[xml_path], ts_type)
tree.write(xml_path, encoding="utf-8", xml_declaration=True)
'''
# ts_name 为码流文件路径名称
def set_xml_config(self, ts_type, xml_path=["all"]):
if ts_type == "t2":
in_file_path = "./xml_file/t2_def.xml"
xml_file_path = r"./config/" + ts_type + ".json"
elif ts_type == "isdbt":
in_file_path = "./xml_file/isdbt_def.xml"
xml_file_path = r"./config/" + ts_type + ".json"
else:
print "error:" + ts_type + ' is error, type should be in ["t2","isdbt"]'
sys.exit(1)
global tree
# 解析原始的xml配置文件
ret_list = self.get_xml_file(in_file_path)
tree.parse(in_file_path)
root = tree.getroot()
# 获取配置文件
xml_config = self.load_xml_edit_config(xml_file_path)
if xml_path[0] == "all":
for key in xml_config.keys():
print "edit to" + key
self.exist_and_replace(xml_config[key], root, ret_list, ts_type)
tree.write(key, encoding="utf-8", xml_declaration=True)
else:
for lst in xml_path:
ret, xml_config_data = self.parse_xml_config(lst, xml_config)
if ret:
self.exist_and_replace(xml_config_data, root, ret_list, ts_type)
tree.write(lst, encoding="utf-8", xml_declaration=True)
if __name__ == "__main__":
xml = XmlEdit()
xml.set_xml_config('isdbt')
xml.set_xml_config('t2')