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python - 无法在 Python 中解压不可迭代的方法对象错误

问题描述

我正在为 Python 中的 A* 搜索构建可视化工具，并在尝试计算节点的 g 分数时遇到以下错误。

    line 115, in g
    x1, y1 = s
TypeError: cannot unpack non-iterable method object

请参见下面的代码：

from graphics import *
import pygame, sys
import math
import numpy as np
from queue import PriorityQueue

pygame.init()

# #set the screen size and captions
size = (500, 500)
rows = 50
margin = 1
screen = pygame.display.set_mode(size)
pygame.display.set_caption("A* Pathfinding")
screen.fill((173, 172, 166))

#define colors
aqua = (0, 255, 255)
black = (0, 0, 0)
blue = (0, 0, 255)
green = (0, 128, 0)
red = (255, 0, 0)
white = (255, 255, 255)
purple = (128, 0, 128)

#initialize PriorityQueue
q = PriorityQueue()



#define all possible states of each node
class Node:
    def __init__(self, row, col, width):
        self.row = row
        self.col = col
        self.x = row*width
        self.y = col*width  
        self.color = white
        self.width = width
        self.neighbors = [(col+1, row), (col-1, row), (col, row+1), (col, row-1)]
        #self.neighbors = []
    
    def get_pos(self):
        return self.row, self.col
    
    def is_closed(self):
        return self.color == red
    
    def is_open(self):
        return self.color == aqua
    
    def is_barrier(self):
        return self.color == black
    
    def is_start(self):
        return self.color == green
    
    def is_end(self):
        return self.color == blue
    
    def reset(self):
        return self.color == white
    
    def close(self):
        self.color = red
    
    def open_node(self):
        self.color = blue
    
    def barrier(self):
        self.color = black
    
    def start(self):
        self.color = green
    
    def end(self):
        self.color = aqua
        
    def path(self):
        self.color = purple

    


def init_grid():
    board = []
    for i in range(rows):
        board.append([])
        for j in range(rows):
            node = Node(i, j, size[0]/rows)
            board[i].append(node)
    return board


#heuristic
def h(c, end):
    x1, y1 = c
    x2, y2 = end
    return abs(x1 - x2) + abs(y1 - y2)


#distance between current node and start node
def g(c, s):
    x1, y1 = s
    x2, y2 = c
    return abs(x1 - x2) + abs(y1 - y2)



    

board = init_grid()


barrier = []
frontier = {}
path = {} 


#starting conditions using Node class and associated methods
start = board[5][5]
goal = board[30][35]
current = start
count = 0

q.put(0, (start))


#main game loop
while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
            
        #allows user to draw barriers
        elif pygame.mouse.get_pressed()[0]:
            pos = pygame.mouse.get_pos()
            y_pos = int(pos[0] // (board[0][0].width + margin))
            x_pos = int(pos[1] // (board[0][0].width + margin))
            board[x_pos][y_pos].barrier()
            barrier.append(board[x_pos][y_pos].get_pos())
    
    #draw the grid
    for i in range(rows):
        for j in range(rows):
            color = board[i][j].color
            #print(board[i][j].color)
            if board[i][j] == start:
                board[i][j].start()
            elif board[i][j] == goal:
                board[i][j].end()
             
            

            pygame.draw.rect(screen, color, [j*(board[0][0].width + margin), i*(board[0][0].width + margin), board[0][0].width, board[0][0].width])
   
    
    #game loop
    if event.type == pygame.KEYDOWN:
        if event.key == pygame.K_SPACE:
            while not q.empty():
                for neighbor in current.neighbors:
                    g_temp = g(current.get_pos, start.get_pos) + 1
                    if g_temp < g(neighbor, start.get_pos()): 
                        f = g_temp + h(current.get_pos(), goal.get_pos())
                        if neighbor not in frontier:
                            q.put((f, neighbor))
                            frontier.add(neighbor)
                            board[neighbor[0]][neighbor[1]].open_node()
                
                
                if current != goal:
                    new = q.get()[1]
                    path.add(current)
                    current = board[new[0]][new[1]]
                
                if current == goal:
                    break


    pygame.display.flip()
        
pygame.quit()

我试过调试这个问题，但我不明白为什么它给了我这个错误。该函数应该接受两个元组参数并返回一个整数作为 g 分数，我相信这是我在游戏循环中通过的。

如果我在这里遗漏了一些明显的错误，请告诉我，我还是编程新手。非常感谢您的时间和帮助！

标签： pythonpygametypeerror

解决方案

你有一段很长的代码。

看来您没有将元组传递给 g()。

我发现了至少一个错误：您必须在方法调用之后添加“()”，否则您将方法名称而不是方法值传递给 g()。

您的代码中的示例：

g_temp = g(current.get_pos, start.get_pos) + 1

应该：

g_temp = g(current.get_pos(), start.get_pos()) + 1

这大概就是问题所在。我没有检查所有其他行，因为这段代码很长；）测试并回来告诉我们。

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