python - 属性错误 : Class Instance has no __call__ method

Question

我对 python 有点陌生，但熟悉 OOP。我正在尝试使用 PyGame 编写游戏。基本上，我的目标是每隔几秒渲染一次树，并在屏幕上移动树矩形。

这是我的代码:

from collections import deque
import pygame,random,sys

pygame.init()
size = 800,600
screen = pygame.display.set_mode(size)

class tree:
    def __init__(self):
            self.img = pygame.image.load("tree.png")
            self.rect = self.img.get_rect()
    def render(self):
            screen.blit(self.img,self.rect)
    def move(self,x,y):
            self.rect = self.rect.move(x,y)

#creating a queue of trees
trees = deque()

#appending the first tree on to the queue 
trees.append(tree())


while 1:


    for event in pygame.event.get():
            if event.type == pygame.QUIT: sys.exit()

    #appending tree() to trees queue every 300 ms
    if pygame.time.get_ticks() % 300 == 0:
            trees.append(tree())

    #rendering and moving all the tree rects of trees in the queue
    for tree in trees:
            tree.render()
            tree.move(20,2)
    pygame.display.flip()

但是当我执行此操作时，前几棵树已成功生成，但随后 PyGame 窗口关闭并出现此错误:

Traceback (most recent call last):
File "error.py", line 25, in <module>
trees.append(tree())
AttributeError: tree instance has no __call__ method

Answer 1

我猜这是因为你有一个变量名 tree(在 tree.render() 中使用)与你的类名冲突。称它为 Tree 会更好(而且更像 pythonic ^^)。