在遵循Python教程创建游戏乒乓时遇到此错误：
Traceback (most recent call last):
File "C:/Users/Gavin/PycharmProjects/lmagPONG/game.py", line 98, in <module>
main()
File "C:/Users/Gavin/PycharmProjects/lmagPONG/game.py", line 91, in main
pong.render(screen)
AttributeError: 'Pong' object has no attribute 'render'
这是我用来创建pong对象的代码（渲染位于底部）：
class Pong(object):
def __init__(self, screensize):
self.screensize = screensize
self.centerx = int(screensize[0] * 0.5)
self.centery = int(screensize[1] * 0.5)
self.radius = 8
self.rect = pygame.Rect(self.centerx - self.radius,
self.centery - self.radius,
self.radius * 2, self.radius * 2)
self.color = (100, 100, 255)
self.direction = [1, 1]
self.speed = 2
self.hit_edge_left = False
self.hit_edge_right = False
def update(self, player_paddle=None, ai_paddle=None):
self.centerx += self.direction[0] * self.speed
self.centery += self.direction[1] * self.speed
self.rect.center = (self.centerx, self.centery)
if self.rect.top <= 0:
self.direction[1] = 1
elif self.rect.bottom >= self.screensize[1] - 1:
self.direction[1] = -1
if self.rect.right >= self.screensize[0] - 1:
self.hit_edge_right = True
elif self.rect.left <= 0:
self.hit_edge_left = True
def render(self, screen):
pygame.draw.circle(screen, self.color, self.rect.center, self.radius, 0)
pygame.draw.circle(screen, (0, 0, 0), self.rect.center, self.radius, 1)
我的主要功能（在底部附近称为渲染）：
def main():
pygame.init()
screensize = (640, 320)
screen = pygame.display.set_mode(screensize)
clock = pygame.time.Clock()
pong = Pong(screensize)
running = True
while running:
# FPS limiting/reporting phase
clock.tick(64)
# event handling phase
for event in pygame.event.get():
if event.type == QUIT:
running = False
# Object updating phase
pong.update()
if pong.hit_edge_left:
print('You Won')
running = False
elif pong.hit_edge_right:
print('You Lose')
running = False
# Rendering phase
screen.fill((100, 100, 100))
pong.render(screen)
pygame.display.flip()
pygame.quit()
我是python的新手，所以即时通讯试图了解这一点，我不确定我是只是犯了一个简单的错误，或者我做错了什么，我只是按照教程。