Python从数据库读取数据写入json格式文件

#!/usr/bin/python
# -*- coding: UTF-8 -*-
#########################################################################
# File Name: addreplace.py
# Author: yuhaitao
# mail: acer_yuhaitao@163.com
# Created Time: Fri 31 Mar 2017 07:05:13 PM PDT
#########################################################################
import os
import sys
import re
import cgi,cgitb
import codecs
import time
import pymysql
import MySQLdb
import json
import codecs

#接收数据
#def RecvFromForm():
form = cgi.FieldStorage()
#getURL = form.getvalue('netURL')
#接受xmlhttp.open("GET","/cgi-bin/SqltoHtml.py?q="+str,true)传递的参数
getNum = form.getvalue('q')

def convert_to_json_string2(contxt,str_ft):
    ret = []  # 需要序列化的列表
    tmp = {'contxt':contxt , 'footer':str_ft}  # 通过data的每一个元素构造一个字典
    ret.append(tmp)
    ret = json.dumps(ret, indent=4)
    return ret


def DbSongName(song_id,cursor):
    sql_song_name = """SELECT * FROM  music163 WHERE song_id = %s """ %(song_id)
    #sql_song_name = """SELECT * FROM  music163 WHERE song_id=186016;"""
    #print sql_song_name
    try:
        cursor.execute(sql_song_name)
        results = cursor.fetchall()
        for row in results:
            name = row[2]
    except Exception , e:
        print "DbSong"+str(e)
        db.rollback()
        db.close()
    return name
def convert_to_json_string1(data):
    return json.dumps(data,indent=4,encoding='utf-8',ensure_ascii=False)



def Dbinsert():
    db = MySQLdb.connect("bdm273925510.my3w.com","bdm273925510","hfdsggsgfs","bdm273925510_db",charset='utf8' )
    cursor = db.cursor()
    sql ="""SELECT * FROM  comment163 WHERE liked  > 50000 order by liked DESC """
    try:
        cursor.execute(sql)
        results = cursor.fetchall()
        for i, row in enumerate(results):
            id = row[0]
            song_id = row[1]
            song_name = DbSongName(song_id,cursor)
            txt = row[2]
            author = row[3]
            liked = row[4]
            data = {'contxt':txt,'footer':u'序列号:'+str(i)+u'--歌曲:'+song_name+u'--评论:'+str(liked)+u'--作者:'+author}
            #convert_to_json_string2(txt,str(i)+song_name+str(liked)+author)
            print convert_to_json_string1(data)
            with codecs.open("J:\\Users\\Acer_haitao\\Desktop\\net.json","a+",encoding='utf-8') as f:
                json.dump(data,f,indent=4,encoding='utf-8',ensure_ascii=False)
    except Exception , e:
        print "Dbinsert "+str(e)
        db.rollback()
        db.close()
Dbinsert()