code: def _mdb_get_database(uri, **kwargs):
      
      if not "tz_aware" in kwargs:
          # default, but not forced
          kwargs["tz_aware"] = True
  
      connection_factory = MongoClient
      _parsed_uri = {}
  
      try:
          _parsed_uri = pymongo.uri_parser.parse_uri(uri)
      except pymongo.errors.InvalidURI:
          # assume URI to be just the database name
          db_name = uri
          _conn = MongoClient()
          pass
      else:
          if "replicaset" in _parsed_uri["options"]:
              connection_factory = MongoReplicaSetClient
          db_name = _parsed_uri.get("database", "pysaml2")
          _conn = connection_factory(uri, **kwargs)
  
      _db = _conn[db_name]
  
      if "username" in _parsed_uri:
          _db.authenticate(
              _parsed_uri.get("username", None),
              _parsed_uri.get("password", None)
          )
  
      return _db
docs: Helper-function to connect to MongoDB and return a database object.
  
      The `uri' argument should be either a full MongoDB connection URI string,
      or just a database name in which case a connection to the default mongo
      instance at mongodb://localhost:27017 will be made.
  
      Performs explicit authentication if a username is provided in a connection
      string URI, since PyMongo does not always seem to do that as promised.
  
      :params database: name as string or (uri, name)
      :returns: pymongo database object