navigation.py 文件源码

def on_start(self, event):
        # choose some random object
        self.target_obj, = random.sample(objects, 1)
        # find the cell in front of the learner
        ws = self.get_world().state
        ld = self.get_world().valid_directions[ws.learner_direction]
        lp = ws.learner_pos
        self.state.initial_count = ws.learner_inventory[self.target_obj]
        # place the object there
        self.get_world().put_entity(lp + ld, self.target_obj, True, True)

        self.add_handler(
            on_state_changed(lambda ws, ts:
                             ws.learner_inventory[self.target_obj] ==
                             ts.initial_count + 1)
            (self.on_object_picked_up))

        self.set_message("You have {indef_object} in front of you. "
                         "Pick up the {object}.".format(
                             indef_object=msg.indef_article(self.target_obj),
                             object=self.target_obj))