PyMongo奇怪的錯誤「TypeError：'數據庫'對象不可調用。」

Question

我有一個奇怪的錯誤。

來源： __init__.py

import os 
import base64 
import uuid 

import tornado.web 
import tornado.httpserver 
import tornado.locale 
import tornado.ioloop 
import tornado.options 

from tornado.options import define, options 

from pymongo.connection import Connection 
from pymongo.database import Database 

from handlers import api 
#from auth import AuthLoginHandler 
#from auth import AuthLogoutHandler 
#from auth import AuthFirstRunHandler 
from handlers import home 

## Options 
define("listen_port",  default = 7456, type = "int", 
       help = "bind to port") 

define("listen_address", default = None, type = "string", 
       help = "bind to address") 

define("static_path",  default = os.path.join(os.path.dirname(__file__), "static"), type = "string", 
       help = "directory to store static resource") 

# http://www.v2ex.com/t/12646 
define("cookie_secret",  default = base64.b64encode(uuid.uuid4().bytes + uuid.uuid4().bytes), type = "string", 
       help = "cookie") 

define("mongo_host",  default = "127.0.0.1", type = "string", 
       help = "hostname or ip of mongo host") 

define("mongo_port",  default = 27017, type = "int", 
       help = "port of mongo host") 

define("mongo_collection", default = "meowth", type = "string", 
       help = "collection name") 

tornado.options.parse_command_line() 

class Application(tornado.web.Application): 
    def __init__(self): 
     tornado.web.Application.__init__(self, [ 
      (r"/i", home.HomeHandler), 
     # (r"/auth/login", AuthLoginHandler), 
     # (r"/auth/logout", AuthLogoutHandler), 
     # (r"/auth/install", AuthFirstRunHandler), 
     # (r"/backstage", BackstageHomeHandler), 
      (r"/api/cluster", api.APIHandler), 
      (r"/api/user", api.APIHandler), 
      (r"/api/connection", api.APIHandler), 
      (r"/api/control", api.APIHandler), 
      (r"/static/(.*)", tornado.web.StaticFileHandler, { "path" : options.static_path }) 
     ],** dict(
      xsrf_cookies = True, 
      cookie_secret = options.cookie_secret 
     )) 

     # init database connection 
     self.mongo = Database(
      Connection(
       options.mongo_host, 
       options.mongo_port 
      ), 
      options.mongo_collection 
     ) 
     #self.mongo = self.mongoConnection[options.mongo_collection] 
     #self.mongo = self.mongoConnection.meowth 

def main(): 
    if options.listen_address == None: 
     tornado.httpserver.HTTPServer(Application()).listen(options.listen_port) 
    else: 
     tornado.httpserver.HTTPServer(Application()).listen(options.listen_port, address = options.listen_address) 

    tornado.ioloop.IOLoop.instance().start() 

if __name__ == "__main__": 
    main() 

base.py

# -*- coding: utf8 -*- 
import tornado.web 
import pymongo 

class BaseHandler(tornado.web.RequestHandler): 

    def __init__(self, application, request, **kwargs): 
     tornado.web.RequestHandler.__init__(self, application, request, **kwargs) 
     self.session_id = self.get_secure_cookie("meowth_session") 
     self.session = {} 

    @property 
    def db(self): 
     print self.application.mongo 
     return self.application.mongo 

    def init_session(self): 
     if not self.session_id: 
      self.session_id = self.db().meowth_sessions.save(
       {"data" : self.session} 
      ) 
     else: 
      self.session = self.db().meowth_sessions.find_one(
       {"_id" : self.session_id} 
      ) 

    def flush_session(self): 
     self.db().meowth_sessions.save(
       {"data" : self.session, 
       "_id" : self.session_id 
       } 
      ) 

    def is_spider(self): 
     # https://bitbucket.org/keakon/doodle/src/3ddf46ac59e7/zh-CN/common.py#cl-512 
     user_agent = self.request.headers["User-Agent"] 
     if 'bot' in user_agent or 'spider' in user_agent: 
      return True 
     return False 

錯誤：

> [root@CloudK02 Meowth]# ./Meowth-Web Database(Connection('127.0.0.1', 
> 27017), u'meowth') [E 120219 15:07:54 web:1031] Uncaught exception GET 
> /i (122.94.31.186) 
>  HTTPRequest(protocol='http', host='us1.loli.vg:7456', method='GET', uri='/i', version='HTTP/1.1', remote_ip='122.94.31.186', 
> body='', headers={'Accept-Language': 'en-US,en;q=0.8', 
> 'Accept-Encoding': 'gzip,deflate,sdch', 'Host': 'us1.loli.vg:7456', 
> 'Accept': 
> 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', 
> 'User-Agent': 'Mozilla/5.0 (Windows NT 5.1) AppleWebKit/535.11 (KHTML, 
> like Gecko) Chrome/17.0.963.56 Safari/535.11', 'Accept-Charset': 
> 'ISO-8859-1,utf-8;q=0.7,*;q=0.3', 'Connection': 'keep-alive', 
> 'Cookie': 'PHPSESSID=rm4ght6ivop9a1hf5oogcft3j4; 
> session_id="MzZkODNiMWMyZjczOWZhNzcxYjU4YTNjNzVhZjA4Yzc=|1329674350|2562f7ed871c1ca3e24dcb5891d6e753cfacfa44"; 
> rock_format=json', 'Cache-Control': 'max-age=0'}) 
>  Traceback (most recent call last): 
>  File "/usr/local/lib/python2.6/site-packages/tornado/web.py", line 988, in _execute 
>   getattr(self, self.request.method.lower())(*args, **kwargs) 
>  File "/home/aveline/Meowth/web/handlers/home.py", line 7, in get 
>   self.init_session() 
>  File "/home/aveline/Meowth/web/handlers/base.py", line 19, in init_session 
>   self.session_id = self.db().meowth_sessions.save(
>  File "build/bdist.linux-x86_64/egg/pymongo/database.py", line 696, in __call__ 
>   "failing because no such method exists." % self.__name) 
>  TypeError: 'Database' object is not callable. If you meant to call the 'meowth' method on a 'Connection' object it is failing because no 
> such method exists. 

它工作得很好，如果我在課堂上應用使用self.mongo。 但是，如果我在類BaseHandler中使用它，我得到一個錯誤。

爲什麼？

Answer 1

您已將db定義爲屬性，這意味着您不必調用它。但是你叫它！

刪除@property或使用self.db而不是self.db()。

---

一如既往，Python的錯誤信息是內容豐富的，你應該看看它們！在這種情況下，您可以看到

TypeError: 'Database' object is not callable. If you meant to call the 'meowth' method on a 'Connection' object it is failing because no such method exists. 

這意味着您正在調用某個數據庫對象（即像函數一樣）。哪裏？

File "/home/aveline/Meowth/web/handlers/base.py", line 19, in init_session 
    self.session_id = self.db().meowth_sessions.save(

請參閱？ self.db是一個屬性，所以給你self.application.mongo。那麼你打電話吧，所以上面的行相當於

self.session_id = self.application.mongo().meowth_sessions.save(

這顯然是錯的。