我是新来的类(class)，这是我第三次尝试制作类(class)。我遇到了一个 NameError，我真的不知道如何解决。看看我的程序，看看你能不能帮上忙。
import random
import math
import pygame
import pickle
# initialise pygame
pygame.init()
# player class
class player(object):
def __init__(self, playerimage, playerX, playerY = 700, playerX_change = 0):
self.playerimage = pygame.image.load("Main Player.png")
self.playerX = 365
self.playerY = 700
self.playerX_change = 0
# laser class
# ready - bullet not on screen
# fire - bullet is shown on screen and is moving
class laser(object):
def __init__(self, laserimage, laserX, laserY, laserY_change):
self.laserimage = pygame.image.load("laser.png")
self.laserX = 0
self.laserY = 700
self.laserY_change = 10
self.laser_state = "ready"
# alien player / random movement = random.randint()
class alien(object):
def __init__(self, alienimage, alienX, alienY, alienX_change, alienY_change, amount_aliens):
self.alienimage = pygame.image.load("alien.png")
self.alienX = []
self.alienY = []
self.alienX_change = []
self.alienY_change = []
self.amount_aliens = 10
for i in range(ufo.amount_aliens):
ufo.alienimage.append(pygame.image.load('alien.png'))
ufo.alienX.append(random.randint(0, 735))
ufo.alienY.append(random.randint(50, 200))
ufo.alienX_change.append(3)
ufo.alienY_change.append(7)
score = 0
# define player
def main_player(x, y):
screen.blit(male.playerimage, (x, y))
# define laster
def fire_laser(x, y):
lasr.laser_state = "fire"
screen.blit(lasr.laserimage, (x + 16, y + 10))
# define alien
def alien(x, y, i):
screen.blit(ufo.alienimage[i], (x, y))
# collision detection
def hascollision(alienX, alienY, laserX, laserY):
distance = math.sqrt((math.pow(alienX - laserX, 2)) + (math.pow(alienY - laserY, 2)))
if distance < 27:
return True
else:
return False
#frames per second
clock = pygame.time.Clock()
# background
background = pygame.image.load('stars.png')
# display and screen title/icon
(width, height) = (800, 800)
screen = pygame.display.set_mode((width, height))
flip = pygame.display.flip()
pygame.display.set_caption("space fighters")
pygame.event.get()
icon = pygame.image.load('logo.png')
pygame.display.set_icon(icon)
from sys import exit
ufo = alien()
lasr = laser(0, 700, 32, 32)
male = player(365, 700,)
# loop of functions
executed = True
while executed:
screen.fill((63, 62, 63))
# image background
screen.blit(background, (0, 0))
for event in pygame.event.get():
# if key pressed, check which input, right or left?
if event.type == pygame.KEYDOWN:
print("key pressed")
if event.key == pygame.K_a:
male.playerX_change = -6
if event.key == pygame.K_s:
male.playerX_change = 6
if event.type == pygame.KEYUP:
if event.key == pygame.K_a or event.key == pygame.K_s:
male.playerX_change = 0
if event.key == pygame.K_SPACE:
if lasr.laser_state is "ready":
lasr.laserX = male.playerX
fire_laser(lasr.laserX, lasr.laserY)
#frames per second is 60fps
clock.tick(60)
# bounrary algorithm, prevents player moving out/enemy.
male.playerX += male.playerX_change
if male.playerX <= 0:
male.playerX = 0
elif male.playerX >= 736:
male.playerX = 736
# boundry algorithm, make sure alien doesn't go out of bountry
for i in range(ufo.amount_aliens):
ufo.alienX[i] += ufo.alienX_change[i]
if ufo.alienX[i] <= 0:
ufo.alienX_change[i] = 4
ufo.alienY[i] += ufo.alienY_change[i]
elif ufo.alienX[i] >= 736:
ufo.alienX_change[i] = -4
ufo.alienY[i] += ufo.alienY_change[i]
# collision
collision = hascollision(ufo.alienX[i], ufo.alienY[i], lasr.laserX, lasr.laserY)
if collision:
lasr.laserY = 650
lasr.laser_state = "ready"
score += 5
print(score)
alienX[i] = random.randint(0, 735)
alienY[i] = random.randint(50, 200)
alien(ufo.alienX[i], ufo.alienY[i], i)
# movement of laser shot
if lasr.laserY <= 0:
lasr.laserY = 650
lasr.laser_state = "ready"
if lasr.laser_state is "fire":
fire_laser(lasr.laserX, lasr.laserY)
lasr.laserY -= lasr.laserY_change
# updates screen to show screen
main_player(male.playerX, male.playerY)
pygame.display.update()
pygame.quit()
这是 Visual Studio 代码给出的错误输出(在第 39 行)
对于我在范围内(ufo.amount_aliens):
NameError: 名称 'ufo' 未定义
最佳答案
alien 类有点困惑。 (虽然很难判断这是否只是 SO 粘贴中的缩进问题。)我将假设需要在类之外制作 ufos 列表，因为这是唯一有意义的事情。稍后在代码中，您声明一个 alien 函数，该函数也将遮挡 alien 类。您需要先解决这个问题 - 最好将其作为 alien 移入 alien.draw() 类
因此，要制作一堆外星人，请创建一个列表:
alien_image = pygame.image.load('alien.png')
all_ufos = []
for i in range( amount_aliens ):
x_pos = random.randint( 0, 735 )
y_pos = random.randint( 50, 200 )
x_speed = 3
y_speed = 7
all_ufos.append( alien( alien_image, x_pos, y_pos, x_speed, y_speed ) )
从
amount_aliens 对象中删除 alien，这样它现在只代表一个外星人。class alien( object ):
def __init__( self, alienimage, alienX, alienY, alienX_change, alienY_change ):
self.alienimage = alienimage
self.alienX = alienX
self.alienY = alienY
self.alienX_change = alienX_change
self.alienY_change = alienY_change
并将支持功能移动到外星人类中。
def draw( self, screen ):
""" Draw the alien to the screen """
screen.blit( self.alienimage, ( self.alienX, self.alienY ) )
def hasCollision( self, laserX, laserY ):
""" Has the laser at collided with this alien? """
distance = math.sqrt((math.pow(self.alienX - laserX, 2)) + (math.pow(self.alienY - laserY, 2)))
return ( distance < 27 ):
这允许你的主循环遍历外星人列表，做一些简单的事情:
### Main Loop
while not exiting:
...
# paint all UFO sprites
for ufo in all_ufos:
ufo.draw( screen )
# check all lasers for collision
for laser in all_lasers:
for ufo in all_ufos:
if ( ufo.hasCollision( laser.laserX, laser.laserY ) ):
print( "*boom*" )
您在这里所做的是重新创建 PyGame Sprite 和 SpriteGroup 类的一些功能。它可能值得 quick read of the documentation 。
关于python - "NameError"有问题，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/60643621/