AttributeError: 'int' object has no attribute 'map' when trying to write a recursive algorithm for a depth limited search

Question

正在尝试为 6 拼图游戏编写深度受限搜索的递归算法，但由于某种原因，我不断收到上述错误并且不明白为什么。这是我的递归深度限制搜索代码：

def rec_dls(node, limit):
    global cutoff_occurred
    cutoff = 0
    failure = -1
    if goal_state == node.state:
        return node
    elif limit == 0:
        return cutoff          # cutoff
    else:
        cutoff_occurred = False
        actions = moves(node.state) # all possibles children of this state
        for action in actions:
            child = State(action, node, node.depth+1, node.cost+1)
            result = rec_dls(child, limit - 1)
            if result == cutoff:
                cutoff_occurred = True
            elif result != failure:
                return result
        if cutoff_occurred:
            return cutoff
        else:
            return failure
        

def dls(limit):
    node = State(initial_state, None, 0, 0)
    return rec_dls(node, limit)

还有州 class:


class State: 
    def __init__(self, state, parent, depth, cost): 
        self.state = state 
        self.parent = parent 
        self.depth = depth 
        self.cost = cost 
        if self.state: 
            self.map = ''.join(str(e) for e in self.state) 
            
    def __eq__(self, other): 
        return self.map == other.map 
    def __lt__(self, other): 
        return self.map < other.map

这是我遇到的更详细的错误：

作为参考，我的工作逻辑基于此（来自“人工智能，一种现代方法”）：

Answer 1

问题不在于 rec_dls returns 和 int。它是 returns 你的 State 对象之一。

考虑以下代码行：

           result = rec_dls(child, limit - 1)
           if result == cutoff:
               # ...

假设 rec_dls 这里 returns 您的 State 对象之一。然后，您将 State 对象与 cutoff 进行比较，后者包含 int 值 0，并且因为您在 State class，此比较导致调用 State.__eq__ 并将 other 设置为 0。

作为 int，0 没有 map 属性，因此您的错误。

也许您想在 __eq__ 方法中包含检查 other 是否是另一个 State 对象：

    def __eq__(self, other): 
        return isinstance(other, State) and self.map == other.map

AttributeError: 'int' object has no attribute 'map' when trying to write a recursive algorithm for a depth limited search

AttributeError: 'int' object has no attribute 'map' when trying to write a recursive algorithm for a depth limited search

python

algorithm

artificial-intelligence

graph