用Pygame和Python做游戏-从入门到精通10，pygamepython,比如说修炼的境界分几

    pressed_keys = pygame.key.get_pressed()
    if pressed_keys[K_SPACE]:
        # Space key has been pressed
        fire()pressed_keys = pygame.key.get_pressed()

background_image_filename = 'sushiplate.jpg'
sprite_image_filename = 'fugu.png'
 
import pygame
from pygame.locals import *
from sys import exit
from gameobjects.vector2 import Vector2
 
pygame.init()
 
screen = pygame.display.set_mode((640, 480), 0, 32)
 
background = pygame.image.load(background_image_filename).convert()
sprite = pygame.image.load(sprite_image_filename).convert_alpha()
 
clock = pygame.time.Clock()
 
sprite_pos = Vector2(200, 150)
sprite_speed = 300.
 
while True:
 
    for event in pygame.event.get():
        if event.type == QUIT:
            exit()
 
    pressed_keys = pygame.key.get_pressed()
 
    key_direction = Vector2(0, 0)
    if pressed_keys[K_LEFT]:
        key_direction.x = -1
    elif pressed_keys[K_RIGHT]:
        key_direction.x = +1
    if pressed_keys[K_UP]:
        key_direction.y = -1
    elif pressed_keys[K_DOWN]:
        key_direction.y = +1
 
    key_direction.normalize()
 
    screen.blit(background, (0,0))
    screen.blit(sprite, sprite_pos)
 
    time_passed = clock.tick(30)
    time_passed_seconds = time_passed / 1000.0
 
    sprite_pos+= key_direction * sprite_speed * time_passed_seconds
 
    pygame.display.update()

background_image_filename = 'sushiplate.jpg'
sprite_image_filename = 'fugu.png'
 
import pygame
from pygame.locals import *
from sys import exit
from gameobjects.vector2 import Vector2
from math import *
 
pygame.init()
 
screen = pygame.display.set_mode((640, 480), 0, 32)
 
background = pygame.image.load(background_image_filename).convert()
sprite = pygame.image.load(sprite_image_filename).convert_alpha()
 
clock = pygame.time.Clock()
 
sprite_pos = Vector2(200, 150)   # 初始位置
sprite_speed = 300.     # 每秒前进的像素数（速度）
sprite_rotation = 0.      # 初始角度
sprite_rotation_speed = 360. # 每秒转动的角度数（转速）
 
while True:
 
    for event in pygame.event.get():
        if event.type == QUIT:
            exit()
 
    pressed_keys = pygame.key.get_pressed()
 
    rotation_direction = 0.
    movement_direction = 0.
 
    # 更改角度
    if pressed_keys[K_LEFT]:
        rotation_direction = +1.
    if pressed_keys[K_RIGHT]:
        rotation_direction = -1.
    # 前进、后退
    if pressed_keys[K_UP]:
        movement_direction = +1.
    if pressed_keys[K_DOWN]:
        movement_direction = -1.
 
    screen.blit(background, (0,0))
 
    # 获得一条转向后的鱼
    rotated_sprite = pygame.transform.rotate(sprite, sprite_rotation)
    # 转向后，图片的长宽会变化，因为图片永远是矩形，为了放得下一个转向后的矩形，外接的矩形势必会比较大
    w, h = rotated_sprite.get_size()
    # 获得绘制图片的左上角（感谢pltc325网友的指正）
    sprite_draw_pos = Vector2(sprite_pos.x-w/2, sprite_pos.y-h/2)
    screen.blit(rotated_sprite, sprite_draw_pos)
 
    time_passed = clock.tick()
    time_passed_seconds = time_passed / 1000.0
 
    # 图片的转向速度也需要和行进速度一样，通过时间来控制
    sprite_rotation += rotation_direction * sprite_rotation_speed * time_passed_seconds
 
    # 获得前进（x方向和y方向），这两个需要一点点三角的知识
    heading_x = sin(sprite_rotation*pi/180.)
    heading_y = cos(sprite_rotation*pi/180.)
    # 转换为单位速度向量
    heading = Vector2(heading_x, heading_y)
    # 转换为速度
    heading *= movement_direction
 
    sprite_pos+= heading * sprite_speed * time_passed_seconds
 
    pygame.display.update()