怎么样通过Python实现多任务MySQL转xml功能？

# -*- coding: utf-8 -*-
'''
Created on 2014/12/27
@author: Yoki
'''
import gevent
import pymysql
from pymysql.cursors import DictCursor
import re
import codecs
db_conn = None
def init_mysql_connect(*args, **kwargs):
 global db_conn
 db_conn = pymysql.connect(*args, **kwargs)
def list_to_xml(result_cur, key_list):
 '''
 mysql 结果集转xml，非xml标准导出方式; xml dom 不支持相同名字的node
 :param result_cur:
 :param key_list:
 :return:
 '''
 content = ''
 content += '<?xml version="1.0" encoding="UTF-8" ?>\r\n'
 content += '<RECORDS>\r\n' # root节点
 for item in result_cur:
  content += '\t<RECORD>\r\n'
  for k in key_list:
   v = item.get(k, '')
   real_value = v
   content += '\t\t<%s>%s</%s>\r\n' % (k, real_value, k)
  content += '\t</RECORD>\r\n'
 content += '</RECORDS>\r\n'
 return content
def get_table_rows(tb_name):
 '''
 获取mysql表rows
 :param tb_name:
 :return:
 '''
 global db_conn
 rows = []
 cursor = db_conn.cursor(cursor=DictCursor)
 cursor.execute('select * from %s' % tb_name)
 for row in cursor:
  rows.append(row)
 return rows
def get_table_keys(tb_name):
 '''
 获取表中字段，顺序 为创建表时的顺序
 :param tb_name:
 :return:
 '''
 global db_conn
 cursor = db_conn.cursor(cursor=DictCursor)
 cur = cursor.execute('show create table %s' % tb_name)
 if cur != 1:
  raise Exception
 for r in cursor:
  create_sql = r['Create Table']
  fields = re.findall('`(.*?)`', create_sql)
  result = []
  # 处理字段
  for i in xrange(1, len(fields)):
   field = fields[i]
   if field in result:
    continue
   result.append(field)
  return result
 return []
def mysql_to_xml(tb_name, output_dir='xml', postfix='xml'):
 '''
 mysql数据导出xml，
 :param tb_name: 数据库表名
 :param output_dir:
 :param postfix:
 :return:
 '''
 rows = get_table_rows(tb_name)
 keys = get_table_keys(tb_name)
 content = list_to_xml(rows, keys)
 fp = codecs.open('%s/%s.%s' % (output_dir, tb_name, postfix), 'w', 'utf-8')
 fp.write(content)
 fp.close()
tb_list = [
 'tb_item',
 'tb_state'
]
if __name__ == '__main__':
 init_mysql_connect(host="localhost", user='user', password="password", database='test', port=3306,
      charset='utf8')
 jobs = []
 for tb_name in tb_list:
  jobs.append(gevent.spawn(mysql_to_xml, tb_name))
 gevent.joinall(jobs)

def list_to_xml(result_cur, key_list):
 fp = codecs.open('test.xml'), 'w', 'utf-8')
 fp.write('<?xml version="1.0" encoding="UTF-8" ?>\r\n')
 fp.write('<RECORDS>\r\n')
 for item in result_cur:
  fp.write('\t<RECORD>\r\n')
  for k in key_list:
   v = item.get(k, '')
   if v is None:
    real_value = ''
   else:
    if type(v) == unicode:
     real_value = cgi.escape(v)
    else:
     real_value = v
   fp.write('\t\t<%s>%s</%s>\r\n' % (k, real_value, k))
  fp.write('\t</RECORD>\r\n')
 fp.write('</RECORDS>\r\n')
 fp.close()