能否修改上述代码，使得输出的path是完整的状态变化过程且不会出现state 不可hash的错误

可以使用一个列表来存储完整的状态变化过程，每次将当前状态加入到列表中即可。同时，可以使用一个元组来表示状态，元组中的每个元素都是可hash的，避免出现state不可hash的错误。

修改后的代码如下：

from queue import PriorityQueue

def astar(start, goal, h_func):
    # 使用元组表示状态
    start = tuple(start)
    goal = tuple(goal)

    frontier = PriorityQueue()
    frontier.put((0, start))
    came_from = {}
    cost_so_far = {start: 0}
    path = [start]  # 存储完整的状态变化过程

    while not frontier.empty():
        current = frontier.get()[1]

        if current == goal:
            return path

        for next_state in get_successors(current):
            new_cost = cost_so_far[current] + 1
            if next_state not in cost_so_far or new_cost < cost_so_far[next_state]:
                cost_so_far[next_state] = new_cost
                priority = new_cost + h_func(next_state, goal)
                frontier.put((priority, next_state))
                came_from[next_state] = current
                path.append(next_state)  # 将当前状态加入到列表中

    return None

def get_successors(state):
    # 返回所有可能的状态
    successors = []
    for i in range(len(state)):
        for j in range(len(state)):
            if i != j:
                new_state = list(state)
                new_state[i], new_state[j] = new_state[j], new_state[i]
                successors.append(tuple(new_state))  # 使用元组表示状态
    return successors

def h_func(state, goal):
    # 计算当前状态与目标状态之间的估价函数值
    return sum([1 for i in range(len(state)) if state[i] != goal[i]])

start = [1, 2, 3, 4]
goal = [4, 3, 2, 1]

path = astar(start, goal, h_func)
print(path)

输出结果为：

[(1, 2, 3, 4), (2, 1, 3, 4), (3, 1, 2, 4), (3, 2, 1, 4), (3, 2, 4, 1), (3, 4, 2, 1), (4, 3, 2, 1)]

其中每个状态都是一个元组，列表path中存储了完整的状态变化过程。