PyMongo 无法识别集合名称是否为客户端

Question

我在我的数据库上打开了一个游标，并且我在数据库中有一个名为 client 的集合。当我尝试执行类似

的查询时

def connect_to_primary(host, port):
    """this function is to connect to primary host in a replicaset"""
    connection = MongoClient(str(host), int(port))
    admindb = connection.admin
    pri_host_port_con = admindb.command("isMaster")
    primary_con = pri_host_port_con['primary']
    pri_host_port = primary_con.replace(':', ' ').split()
    pri_host = pri_host_port[0]
    pri_port = pri_host_port[1]
    final_connection = MongoClient(str(pri_host), int(pri_port))
    return final_connection

connect_to_primary(host,port)[db].client.find({}).distinct('clientid')

我收到以下错误：

File "/usr/lib64/python2.7/site-packages/pymongo/database.py", line 1116, in __call__
    self.__name, self.__client.__class__.__name__))
TypeError: 'Database' object is not callable. If you meant to call the 'find' method on a 'MongoClient' object it is failing because no such method exists.

这是怎么回事？

Answer 1

你得到这个的原因是 Database instances have a client 属性 returns 数据库的客户端实例，如以下交互式 Python 会话所示。

>>> import pymongo
>>> connection = pymongo.MongoClient()
>>> db = connection["test"]
>>> db
Database(MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True), 'test')
>>> db.client
MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True)

唯一的解决方案是使用 get_collection 方法或 [] 运算符。

>>> db["client"]
Collection(Database(MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True), 'test'), 'client')
>>> db.get_collection("client")
Collection(Database(MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True), 'test'), 'client')

PyMongo 无法识别集合名称是否为客户端

PyMongo not recognizing if the name of the collection is client

mongodb

pymongo

mongodb-query

pymongo-3.x