为什么我的Python脚本不能识别导入模块中的类？

Question

collection.py

import sys
import os
import pymongo
from pymongo import MongoClient

class Collection():
    """returns a collection curser from mongodb"""

    client = MongoClient()

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

    def getCollection(self):
        data_base = getattr(self.client, self.db)
        collObject = getattr(data_base, self.collection_name)
        return collObject

main.py

import sys
import os
import collection

def main():
    pass

if __name__ == '__main__':
    print"Begin Main"

    agents = Collection('hkpr_restore','agents')
    print "agents is" , agents

这些文件位于同一目录中.main.py然而,当我跑步时,我收到一个错误:

Begin Main
Traceback (most recent call last):
  File "main.py", line 23, in <module>
    agents = Collection('hkpr_restore','agents')
NameError: name 'Collection' is not defined

根据我的阅读,如果文件在同一目录中,我需要做的就是使用import collection.

我错过了什么吗？

Answer 1

你只是导入collection,而不是Collection.

要么from collection import Collection实例化,要么在实例化时使用完全限定名称:agents = collection.Collection('hkpr_restore','agents').