连接、查找和更新mongodb的python类

Question

我正在尝试创建一个python类来连接、更新和查找我的mongodb数据库。我可以连接，但在尝试使用此类查找数据时会出错。如果有人能帮我调试这个问题，我将不胜感激。你知道吗

以下是我的类定义：

import string
import pymongo

class mongoresultDAO(object):

       def __init__(self, database, collection):
               self.db = database
               self.dbcollection = collection
               self.connect()

       def find_names(self, model, query, param):
               #print query
               #print param
               mongor1 = self.dbcollection.find(query, param)
               #print mongor1
               return mongor1

       def update_collection(self,jsonObj):
               self.dbcollection.insert(jsonObj,check_keys=False)

      def connect(self):
               client = pymongo.MongoClient("localhost", 27017)
               db = client[self.db]
               coll_obj = db[self.dbcollection]
               return coll_obj

尝试查找信息时出现以下错误：

a=sresult1.find_names("test", query, param) File 
"/Documents/lab_python/mongoresultDAO.py", line 14, in find_names mongor1 = 
self.dbcollection.find(query, param) TypeError: slice indices must be 
integers or None or have an __index__ method

谢谢