python 中导入mongodb 问题 报错

Question

raceback (most recent call last):
  File "/home/shenjianlin/.local/lib/python3.4/site-packages/twisted/internet/defer.py", line 653, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/home/shenjianlin/my_project/Espider/Espider/pipelines/MongoPipelines.py", line 25, in process_item
    res = self.Mongodb.find(key_word)
  File "/usr/lib64/python3.4/site-packages/pymongo/collection.py", line 3100, in __call__
    self.__name)
TypeError: 'Collection' object is not callable. If you meant to call the 'find' method on a 'Database' object it is failing because no such method exists.
2018-10-11 19:30:41 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://api.zsxq.com/v1.10/files/51114252822224/download_url> (referer: https://wx.zsxq.com/dweb/)
2018-10-11 19:30:41 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://api.zsxq.com/v1.10/files/51114252822254/download_url> (referer: https://wx.zsxq.com/dweb/)
2018-10-11 19:30:41 [scrapy.core.scraper] ERROR: Error processing {'file_url': 'https://files.zsxq.com/lpawwLc8YufA3n22KiwDGuc1-7Mu?attname=%E5%8D%8E%E7%99%BB%E5%9B%BD%E9%99%85-MEMS%EF%BC%8C%E6%9C%BA%E5%99%A8%E4%BA%BA%E5%92%8C%E6%99%BA%E8%83%BD%E6%B1%BD%E8%BD%A6-2018.03-32%E9%A1%B5.pdf&e=1874736000&token=kIxbL07-8jAj8w1n4s9zv64FuZZNEATmlU_Vm6zD:IfFwug2_hLLVlHfp8RUz-ky4x3A=',
 'name': '华登国际-MEMS，机器人和智能汽车-2018.03-32页.pdf'}
Traceback (most recent call last)


import pymongo
from scrapy.exceptions import DropItem


class MongodbPipeline(object):

    def __init__(self, MongodbHost, MongodbPort, MongodbName, MongodbCollection):
        self.MongodbHost = MongodbHost
        self.MongodbPort = MongodbPort
        self.MongodbName = MongodbName
        self.MongodbCollection = MongodbCollection

    @classmethod
    def from_crawler(cls, crawler):
        return cls(MongodbHost=crawler.settings.get('MONGODB_HOST'), MongodbPort=crawler.settings.get('MONGODB_PORT'),
                   MongodbName=crawler.settings.get('MONGODB_DBNAME'),
                   MongodbCollection=crawler.settings.get('MONGODB_COLLECTION'))

    def open_spider(self, spider):
        self.Client = pymongo.MongoClient(self.MongodbHost, self.MongodbPort)
        self.Mongodb = self.Client[self.MongodbName]

    def process_item(self, item, spider):
        key_word = {"file_url": item['file_url'], "name": item['name']}
        res = self.Mongodb.find(key_word)
        for i in res:
            if i:
                raise DropItem("Duplicate item found: %s" % item)
            else:

                self.Mongodb.insert({"file_url": item['file_url'], "name": item['name']})

                return item

    def close_spider(self, spider):
        self.Client.close()

Answer 1

process_item 函数中第二行， self.Mongodb.find 这么写是不对的。
数据库对象没有find 函数。应使用数据库中的 Collection 对象进行查找。
应是 self.Mongodb[collection_name].find(xxx)