无法创建 class 的两个实例（使用 pygame，试图用两条蛇制作贪吃蛇游戏）
Unable to create two instances of a class (using pygame, trying to make snake game with two snakes)
我创建了一个 class，它使用 pygame 定义和创建了一条蛇。当我创建一个蛇实例 class 时，将正确创建一条蛇，但是当我尝试创建两个实例时，我的代码不会创建第二条蛇。我不确定这是因为我错误地使用了 pygame，还是因为我在 classes 中做错了什么。
这是我的代码；它有点长，但我已经把它全部包括在内，因为我不知道问题出在哪里。我很确定我正在正确处理所有变量和参数，并且处理按键也是正确的。如果您将此代码复制并粘贴到解释器中，如果您说您想要一条蛇，它可以正常工作，但如果您想要创建两条蛇，它就不起作用。
import os
os.environ['PYGAME_HIDE_SUPPORT_PROMPT'] = "hide"; import pygame
import random
import time
import copy
black = pygame.Color(0, 0, 0)
class Snake():
def __init__(self, game_window, controls, color, position, speed, window_specs,can_touch=True,respawn=True):
self.game_window = game_window
self.color = color
self.window_x = window_specs[0]
self.window_y = window_specs[1]
self.can_touch = can_touch
self.respawn = respawn
self.snake_position = position.copy()
self.snake_body = [position.copy()]
self.speed = speed
self.controls = controls.copy()
self.direction = 'RIGHT'
self.change_to = self.direction
self.moving = True
self.fps = pygame.time.Clock()
self.start_moving()
def start_moving(self):
#Handles the controls and movement. Control first snake with 'wasd'. Control second snake with arrow keys.
while self.moving == True:
for event in pygame.event.get():
if event.type == pygame.KEYDOWN:
if event.key == self.controls[0]:
self.change_to = 'UP'
if event.key == self.controls[1]:
self.change_to = 'LEFT'
if event.key == self.controls[2]:
self.change_to = 'DOWN'
if event.key == self.controls[3]:
self.change_to = 'RIGHT'
if self.change_to == 'UP' and self.direction != 'DOWN':
self.direction = 'UP'
if self.change_to == 'DOWN' and self.direction != 'UP':
self.direction = 'DOWN'
if self.change_to == 'LEFT' and self.direction != 'RIGHT':
self.direction = 'LEFT'
if self.change_to == 'RIGHT' and self.direction != 'LEFT':
self.direction = 'RIGHT'
if self.direction == 'UP':
self.snake_position[1] -= 10
if self.direction == 'LEFT':
self.snake_position[0] -= 10
if self.direction == 'DOWN':
self.snake_position[1] += 10
if self.direction == 'RIGHT':
self.snake_position[0] += 10
self.snake_body.insert(0, list(self.snake_position))
self.snake_body.pop()
self.game_window.fill(black)
for pos in self.snake_body:
pygame.draw.rect(self.game_window,self.color,pygame.Rect(pos[0],pos[1],10,10))
#Toggles whether snake will die if touching itself
if self.can_touch == False:
for block in self.snake_body[1:]:
if self.snake_position[0] == block[0] and self.snake_position[1] == block[1]:
self.die()
#Kills snake if snake touches the edge of the window
if self.snake_position[0] < 0 or self.snake_position[0] > (self.window_x - 10):
self.die()
if self.snake_position[1] < 0 or self.snake_position[1] > (self.window_y - 10):
self.die()
pygame.display.update()
self.fps.tick(self.speed)
def die(self):
#Reset the snake
self.moving = False
self.game_window.fill(black)
self.snake_body = []
self.position = []
pygame.display.update()
time.sleep(1)
#Makes the snake respawn in a random location
if self.respawn == True:
self.direction = 'RIGHT'
self.change_to = self.direction
self.snake_position = [random.randrange(1, (self.window_x//100)) * 10,
random.randrange(1, (self.window_y//100)) * 10]
self.snake_body = [self.snake_position.copy()]
self.moving = True
self.start_moving()
class App():
def __init__(self,num_players,can_touch=True,respawn=True):
self.controls = [[pygame.K_w, pygame.K_a, pygame.K_s, pygame.K_d],
[pygame.K_UP,pygame.K_LEFT,pygame.K_DOWN,pygame.K_RIGHT]]
self.starting_positions = [[100,50], [200, 100]]
self.speed = 15
self.window_specs = [720,480]
self.num_players = num_players
self.can_touch = can_touch
self.respawn = respawn
self.players = {}
#Start up pygame
pygame.init()
pygame.display.set_caption('Snake Game')
self.game_window = pygame.display.set_mode((self.window_specs[0], self.window_specs[1]))
self.get_players()
def get_players(self):
#Let the players choose what color they want
player_color = []
for i in range(self.num_players):
player_color.append(input(f'Player {i+1}, what color do you want your snake to be? '))
if player_color[i] == 'red':
player_color[i] = pygame.Color(255,0,0)
elif player_color[i] == 'green':
player_color[i] = pygame.Color(0,255,0)
elif player_color[i] == 'blue':
player_color[i] = pygame.Color(0,0,255)
else:
player_color[i] = pygame.Color(255,255,255)
#Create the Snakes, this is the bit that does not work.
for i in range(self.num_players):
self.players[f'player{i+1}'] = Snake(self.game_window,self.controls[i],player_color[i],self.starting_positions[i],self.speed,self.window_specs)
if __name__ == "__main__":
num_players = int(input('1 or 2 players: '))
App(num_players)
这里的问题是您没有为该游戏设置专用的游戏循环。您的游戏的“游戏循环”现在位于单个蛇对象中。你的 Snake.start_moving 函数是保持在 运行ning 上的东西，你看到你的蛇移动的地方等。在你创建一条蛇的情况下，你是 运行ning 那是蛇的 start_moving 函数，所以表面上一切看起来都很好。
如果你是运行 2条蛇，第一条蛇的start_moving函数被调用，你被困在那里。第二条蛇还没有被创造出来。为了说服自己，尝试在函数外添加一个 if event.key is q, return 。然后你会看到当你要两条蛇时，第一条蛇会运行，然后你按q，第一条蛇消失，第二条蛇出现
解决您的问题的方法是在您的项目中创建一个专用的游戏循环，并将所有游戏更新委托给那里。有几种不同的方法可以做到这一点，所以我会把它留给你来设计。但总的来说，这是我在伪代码中推荐的：
snakes = [Snake() for _ in range(numplayers)]
while True:
for event in pg.events():
if event is keypress:
for snake in snakes:
snake.handle_keys(event.key)
for snake in snakes:
snake.update(dt)
for snake in snakes:
snake.draw(display)
display.flip()
tick() # or calculate dt
整个应用程序需要一个应用程序循环，而不是每条蛇都需要一个单独的应用程序。从 Snake class:
中删除应用程序循环
class Snake():
def __init__(self, game_window, controls, color, position, window_specs,can_touch=True,respawn=True):
self.game_window = game_window
self.color = color
self.window_x = window_specs[0]
self.window_y = window_specs[1]
self.can_touch = can_touch
self.respawn = respawn
self.snake_position = position.copy()
self.snake_body = [position.copy()]
self.controls = controls.copy()
self.direction = (1, 0)
def move(self, event_list):
#Handles the controls and movement. Control first snake with 'wasd'. Control second snake with arrow keys.
for event in event_list:
if event.type == pygame.QUIT:
pygame.quit()
if event.type == pygame.KEYDOWN:
if event.key == self.controls[0] and self.direction[1] <= 0:
self.direction = (0, -1)
if event.key == self.controls[1] and self.direction[0] <= 0:
self.direction = (-1, 0)
if event.key == self.controls[2] and self.direction[1] >= 0:
self.direction = (0, 1)
if event.key == self.controls[3] and self.direction[0] >= 0:
self.direction = (1, 0)
self.snake_position[0] += self.direction[0] * 10
self.snake_position[1] += self.direction[1] * 10
self.snake_body.insert(0, list(self.snake_position))
self.snake_body.pop()
for pos in self.snake_body:
pygame.draw.rect(self.game_window,self.color,pygame.Rect(pos[0],pos[1],10,10))
#Toggles whether snake will die if touching itself
if self.can_touch == False:
for block in self.snake_body[1:]:
if self.snake_position[0] == block[0] and self.snake_position[1] == block[1]:
self.die()
#Kills snake if snake touches the edge of the window
if self.snake_position[0] < 0 or self.snake_position[0] > (self.window_x - 10):
self.die()
if self.snake_position[1] < 0 or self.snake_position[1] > (self.window_y - 10):
self.die()
def die(self):
self.snake_body = []
self.position = []
#Makes the snake respawn in a random location
if self.respawn == True:
self.direction = (1, 0)
self.snake_position = [random.randrange(1, (self.window_x//100)) * 10,
random.randrange(1, (self.window_y//100)) * 10]
self.snake_body = [self.snake_position.copy()]
但是在App中添加一个应用程序循环：
class App():
# [...]
def get_players(self):
#Let the players choose what color they want
player_color = []
color_dict = {'red': (255, 0, 0), 'green': (0, 255, 0), 'blue': (0, 0, 255)}
for i in range(self.num_players):
color = input(f'Player {i+1}, what color do you want your snake to be? ')
player_color.append(color_dict[color] if color in color_dict else (255, 255, 255))
#Create the Snakes, this is the bit that does not work.
for i in range(self.num_players):
self.players[f'player{i+1}'] = Snake(self.game_window,self.controls[i],player_color[i],self.starting_positions[i],self.window_specs)
clock = pygame.time.Clock()
run = True
while run:
clock.tick(self.speed)
event_list = pygame.event.get()
for event in event_list:
if event.type == pygame.QUIT:
run = False
self.game_window.fill(black)
for key in self.players:
self.players[key].move(event_list)
pygame.display.update()
pygame.quit()
我创建了一个 class，它使用 pygame 定义和创建了一条蛇。当我创建一个蛇实例 class 时，将正确创建一条蛇，但是当我尝试创建两个实例时，我的代码不会创建第二条蛇。我不确定这是因为我错误地使用了 pygame，还是因为我在 classes 中做错了什么。
这是我的代码；它有点长，但我已经把它全部包括在内，因为我不知道问题出在哪里。我很确定我正在正确处理所有变量和参数，并且处理按键也是正确的。如果您将此代码复制并粘贴到解释器中，如果您说您想要一条蛇，它可以正常工作，但如果您想要创建两条蛇，它就不起作用。
import os
os.environ['PYGAME_HIDE_SUPPORT_PROMPT'] = "hide"; import pygame
import random
import time
import copy
black = pygame.Color(0, 0, 0)
class Snake():
def __init__(self, game_window, controls, color, position, speed, window_specs,can_touch=True,respawn=True):
self.game_window = game_window
self.color = color
self.window_x = window_specs[0]
self.window_y = window_specs[1]
self.can_touch = can_touch
self.respawn = respawn
self.snake_position = position.copy()
self.snake_body = [position.copy()]
self.speed = speed
self.controls = controls.copy()
self.direction = 'RIGHT'
self.change_to = self.direction
self.moving = True
self.fps = pygame.time.Clock()
self.start_moving()
def start_moving(self):
#Handles the controls and movement. Control first snake with 'wasd'. Control second snake with arrow keys.
while self.moving == True:
for event in pygame.event.get():
if event.type == pygame.KEYDOWN:
if event.key == self.controls[0]:
self.change_to = 'UP'
if event.key == self.controls[1]:
self.change_to = 'LEFT'
if event.key == self.controls[2]:
self.change_to = 'DOWN'
if event.key == self.controls[3]:
self.change_to = 'RIGHT'
if self.change_to == 'UP' and self.direction != 'DOWN':
self.direction = 'UP'
if self.change_to == 'DOWN' and self.direction != 'UP':
self.direction = 'DOWN'
if self.change_to == 'LEFT' and self.direction != 'RIGHT':
self.direction = 'LEFT'
if self.change_to == 'RIGHT' and self.direction != 'LEFT':
self.direction = 'RIGHT'
if self.direction == 'UP':
self.snake_position[1] -= 10
if self.direction == 'LEFT':
self.snake_position[0] -= 10
if self.direction == 'DOWN':
self.snake_position[1] += 10
if self.direction == 'RIGHT':
self.snake_position[0] += 10
self.snake_body.insert(0, list(self.snake_position))
self.snake_body.pop()
self.game_window.fill(black)
for pos in self.snake_body:
pygame.draw.rect(self.game_window,self.color,pygame.Rect(pos[0],pos[1],10,10))
#Toggles whether snake will die if touching itself
if self.can_touch == False:
for block in self.snake_body[1:]:
if self.snake_position[0] == block[0] and self.snake_position[1] == block[1]:
self.die()
#Kills snake if snake touches the edge of the window
if self.snake_position[0] < 0 or self.snake_position[0] > (self.window_x - 10):
self.die()
if self.snake_position[1] < 0 or self.snake_position[1] > (self.window_y - 10):
self.die()
pygame.display.update()
self.fps.tick(self.speed)
def die(self):
#Reset the snake
self.moving = False
self.game_window.fill(black)
self.snake_body = []
self.position = []
pygame.display.update()
time.sleep(1)
#Makes the snake respawn in a random location
if self.respawn == True:
self.direction = 'RIGHT'
self.change_to = self.direction
self.snake_position = [random.randrange(1, (self.window_x//100)) * 10,
random.randrange(1, (self.window_y//100)) * 10]
self.snake_body = [self.snake_position.copy()]
self.moving = True
self.start_moving()
class App():
def __init__(self,num_players,can_touch=True,respawn=True):
self.controls = [[pygame.K_w, pygame.K_a, pygame.K_s, pygame.K_d],
[pygame.K_UP,pygame.K_LEFT,pygame.K_DOWN,pygame.K_RIGHT]]
self.starting_positions = [[100,50], [200, 100]]
self.speed = 15
self.window_specs = [720,480]
self.num_players = num_players
self.can_touch = can_touch
self.respawn = respawn
self.players = {}
#Start up pygame
pygame.init()
pygame.display.set_caption('Snake Game')
self.game_window = pygame.display.set_mode((self.window_specs[0], self.window_specs[1]))
self.get_players()
def get_players(self):
#Let the players choose what color they want
player_color = []
for i in range(self.num_players):
player_color.append(input(f'Player {i+1}, what color do you want your snake to be? '))
if player_color[i] == 'red':
player_color[i] = pygame.Color(255,0,0)
elif player_color[i] == 'green':
player_color[i] = pygame.Color(0,255,0)
elif player_color[i] == 'blue':
player_color[i] = pygame.Color(0,0,255)
else:
player_color[i] = pygame.Color(255,255,255)
#Create the Snakes, this is the bit that does not work.
for i in range(self.num_players):
self.players[f'player{i+1}'] = Snake(self.game_window,self.controls[i],player_color[i],self.starting_positions[i],self.speed,self.window_specs)
if __name__ == "__main__":
num_players = int(input('1 or 2 players: '))
App(num_players)
这里的问题是您没有为该游戏设置专用的游戏循环。您的游戏的“游戏循环”现在位于单个蛇对象中。你的 Snake.start_moving 函数是保持在 运行ning 上的东西，你看到你的蛇移动的地方等。在你创建一条蛇的情况下，你是 运行ning 那是蛇的 start_moving 函数，所以表面上一切看起来都很好。
如果你是运行 2条蛇，第一条蛇的start_moving函数被调用，你被困在那里。第二条蛇还没有被创造出来。为了说服自己，尝试在函数外添加一个 if event.key is q, return 。然后你会看到当你要两条蛇时，第一条蛇会运行，然后你按q，第一条蛇消失，第二条蛇出现
解决您的问题的方法是在您的项目中创建一个专用的游戏循环，并将所有游戏更新委托给那里。有几种不同的方法可以做到这一点，所以我会把它留给你来设计。但总的来说，这是我在伪代码中推荐的：
snakes = [Snake() for _ in range(numplayers)]
while True:
for event in pg.events():
if event is keypress:
for snake in snakes:
snake.handle_keys(event.key)
for snake in snakes:
snake.update(dt)
for snake in snakes:
snake.draw(display)
display.flip()
tick() # or calculate dt
整个应用程序需要一个应用程序循环，而不是每条蛇都需要一个单独的应用程序。从 Snake class:
class Snake():
def __init__(self, game_window, controls, color, position, window_specs,can_touch=True,respawn=True):
self.game_window = game_window
self.color = color
self.window_x = window_specs[0]
self.window_y = window_specs[1]
self.can_touch = can_touch
self.respawn = respawn
self.snake_position = position.copy()
self.snake_body = [position.copy()]
self.controls = controls.copy()
self.direction = (1, 0)
def move(self, event_list):
#Handles the controls and movement. Control first snake with 'wasd'. Control second snake with arrow keys.
for event in event_list:
if event.type == pygame.QUIT:
pygame.quit()
if event.type == pygame.KEYDOWN:
if event.key == self.controls[0] and self.direction[1] <= 0:
self.direction = (0, -1)
if event.key == self.controls[1] and self.direction[0] <= 0:
self.direction = (-1, 0)
if event.key == self.controls[2] and self.direction[1] >= 0:
self.direction = (0, 1)
if event.key == self.controls[3] and self.direction[0] >= 0:
self.direction = (1, 0)
self.snake_position[0] += self.direction[0] * 10
self.snake_position[1] += self.direction[1] * 10
self.snake_body.insert(0, list(self.snake_position))
self.snake_body.pop()
for pos in self.snake_body:
pygame.draw.rect(self.game_window,self.color,pygame.Rect(pos[0],pos[1],10,10))
#Toggles whether snake will die if touching itself
if self.can_touch == False:
for block in self.snake_body[1:]:
if self.snake_position[0] == block[0] and self.snake_position[1] == block[1]:
self.die()
#Kills snake if snake touches the edge of the window
if self.snake_position[0] < 0 or self.snake_position[0] > (self.window_x - 10):
self.die()
if self.snake_position[1] < 0 or self.snake_position[1] > (self.window_y - 10):
self.die()
def die(self):
self.snake_body = []
self.position = []
#Makes the snake respawn in a random location
if self.respawn == True:
self.direction = (1, 0)
self.snake_position = [random.randrange(1, (self.window_x//100)) * 10,
random.randrange(1, (self.window_y//100)) * 10]
self.snake_body = [self.snake_position.copy()]
但是在App中添加一个应用程序循环：
class App():
# [...]
def get_players(self):
#Let the players choose what color they want
player_color = []
color_dict = {'red': (255, 0, 0), 'green': (0, 255, 0), 'blue': (0, 0, 255)}
for i in range(self.num_players):
color = input(f'Player {i+1}, what color do you want your snake to be? ')
player_color.append(color_dict[color] if color in color_dict else (255, 255, 255))
#Create the Snakes, this is the bit that does not work.
for i in range(self.num_players):
self.players[f'player{i+1}'] = Snake(self.game_window,self.controls[i],player_color[i],self.starting_positions[i],self.window_specs)
clock = pygame.time.Clock()
run = True
while run:
clock.tick(self.speed)
event_list = pygame.event.get()
for event in event_list:
if event.type == pygame.QUIT:
run = False
self.game_window.fill(black)
for key in self.players:
self.players[key].move(event_list)
pygame.display.update()
pygame.quit()