# characters.py
from evennia import DefaultCharacter

class Character(DefaultCharacter):
    def at_after_move(self, source):
        if self.access(self.location, 'view'):
            self.msg( self.location.return_short_appearance(self) )
        else:
            return("Unable to view {}".format(self.location.key))

# rooms.py
from evennia import DefaultRoom

class Room(DefaultRoom):
    def return_short_appearance(self, looker):
        desc = self.key + "\n"
        desc += str(self.short_desc) # I'm lazy - this will convert the possible
                                     # None value to a string - literally "None"
        return desc