Question

我有一个班级：

import sys
import os
import pymongo
from pymongo import MongoClient

class Collection():
    def __init__(self, db, collection_name):
        self.db = db
        self.collection_name = collection_name

        if not hasattr(self.__class__, 'client'):
            self.__class__.client = MongoClient()

        self.data_base = getattr(self.client, self.db)
        self.collection = getattr(self.data_base, self.collection_name)

我按如下方式创建了类实例：

    def getCollections(self):
        collections_dict = {}
        for i in range(len(self.db_collection_names)):
            collections_dict[self.db_collection_names[i]] = Collection(self.database_name, self.db_collection_names[i])
        return collections_dict

db_collection_names包含email_logs。我创建了一个emails实例，如下所示：

emails = collections_dict['email_logs']

print emails收益<collection.Collection instance at 0x105ce6248>

print emails.find()收益：

Traceback (most recent call last):
  File "main.py", line 75, in <module>
program.runProgram()
  File "main.py", line 63, in runProgram
print emails.find
AttributeError: Collection instance has no attribute 'find'

为什么会出错？

Answer 1

不确定为什么要重新定义Pymongo Collection课程。

from pymongo import MongoClient

db = MongoClient().my_database  # create an instance of pymongo Database
emails = db.emails  # create an instance of pymongo Collection

emails.find()  # yeilds a pymongo Cursor (containing the query results)

Answer 2

我在find()方法

之前错过了这个集合

emails.collection.find()

不能在pymongo的集合实例中使用find（）

2 个答案: