def _read_preference(self, allow_secondary):
        """ Return the mongo read preference given an 'allow_secondary' argument
        """
        allow_secondary = self._allow_secondary if allow_secondary is None else allow_secondary
        return ReadPreference.NEAREST if allow_secondary else ReadPreference.PRIMARY
def _read_preference ( self , allow_secondary ) : allow_secondary = self . _allow_secondary if allow_secondary is None else allow_secondary return ReadPreference . NEAREST if allow_secondary else ReadPreference . PRIMARY
Return the mongo read preference given an 'allow_secondary' argument