代码，一次编写，多次阅读。 Code is write-once, read- many

import pygame,sys

pygame.init()
screen=pygame.display.set_mode([400,600])
screen.fill([0,0,0])
ship=pygame.image.load('lunarlander.png')
moon=pygame.image.load('moonsurface.png')
ground=540
start=90
clock=pygame.time.Clock()
ship_mass=5000.0
fuel=5000.0
velocity=-100.0
gravity=10
height=2000
thrust=0
delta_v=0
y_pos=90
held_down=False
class ThrottleClass(pygame.sprite.Sprite):
    def __init__(self,location=[0,0]):
        pygame.sprite.Sprite.__init__(self)
        image_surface=pygame.surface.Surface([30,10])
        image_surface.fill([128,128,128])
        self.image=image_surface.convert()
        self.rect=self.image.get_rect()
        self.rect.left,self.rect.centery=location

def calculate_velocity():
    global thrust,fuel,velocity,deta_v,height,y_pos
    delta_t=1/fps
    thrust=(500-myThrottle.rect.centery)*5.0
    fuel-=thrust/(10*fps)
    if fuel<0: fuel=0.0
    if fuel<0.1: thrust=0.0
    delta_v=delta_t*(-gravity+200*thrust/(ship_mass+fuel))
    velocity=velocity+delta_v
    delta_h=velocity*delta_t
    height=height+delta_h
    y_pos=ground-(height*(ground-start)/2000)-90

def display_stats():
    v_str="velocity: %u m/s"% velocity
    h_str="height: %.1f"%height
    t_str="thrust: %i"%thrust
    a_str="acceleration: %.if"%(delta_v*fps)
    f_str="fuel: %i"%fuel
    v_font=pygame.font.Font(None,26)

    v_surf=v_font.render(v_str,1,(255,255,255))
    screen.blit(v_surf,[10,50])
    a_font=pygame.font.Font(None,26)
    a_surf=a_font.render(a_str,1,(255,255,255))
    screen.blit(a_surf,[10,100])
    h_font=pygame.font.Font(None,26)
    h_surf=h_font.render(h_str,1,(255,255,255))
    screen.blit(h_surf,[10,150])
    t_font=pygame.font.Font(None,26)
    t_surf=t_font.render(t_str,1,(255,255,255))
    screen.blit(t_surf,[10,200])
    f_font=pygame.font.Font(None,26)
    f_surf=f_font.render(f_str,1,[255,255,255])
    screen.blit(f_surf,[60,300])

def display_flames():
    flame_size=thrust/15
    for i in range(2):
        startx=252-10+i*19
        starty=y_pos+83
        pygame.draw.polygon(screen,[255,109,14],[(startx,starty),
                                                 (startx+4,starty+flame_size),
                                                 (startx+8,starty)],0)

def display_final():
    final1="Game Over"
    final2="You landed at %.1fm/s"%velocity
    if velocity>-5:
        final3="Nice landing"
        final4="I hear li is hiring"
    elif velocity>-15:
        final3="Ouch! A bit rough,but you sursivived"
        final4="You'll do better next time."
    else:
        final3="People,You crashed a 30 Billion dollar ship"
        final4="How are you going home?"
    pygame.draw.rect(screen,[0,0,0],[5,5,350,280],0)
    f1_font=pygame.font.Font(None,70)
    f1_surf=f1_font.render(final1,1,(255,255,255))
    screen.blit(f1_surf,[20,50])
    f2_font=pygame.font.Font(None,40)
    f2_surf=f2_font.render(final2,1,(255,255,255))
    screen.blit(f2_surf,[20,110])
    f3_font=pygame.font.Font(None,26)
    f3_surf=f3_font.render(final3,1,(255,255,255))
    screen.blit(f3_surf,[20,150])
    f4_font=pygame.font.Font(None,26)
    f4_surf=f4_font.render(final4,1,(255,255,255))
    screen.blit(f4_surf,[20,180])
    pygame.display.flip()

myThrottle=ThrottleClass([15,500])
running=True
while running:
    clock.tick(30)
    fps=clock.get_fps()
    if fps<1: fps=30
    if height>0.01:
        calculate_velocity()
        screen.fill([0,0,0])
        display_stats()
        pygame.draw.rect(screen,[0,0,255],[80,350,24,100],2)
        fuelbar=96*fuel/5000
        pygame.draw.rect(screen,[255,0,0],[84,448-fuelbar,18,fuelbar],0)
        pygame.draw.rect(screen,[255,0,0],[25,300,10,200],0)
        screen.blit(moon,[0,500,400,100])
        pygame.draw.rect(screen,[60,60,60],[220,535,70,5],0)
        screen.blit(myThrottle.image,myThrottle.rect)
        display_flames()
        screen.blit(ship,[230,y_pos,50,90])
        instruct1="Land softly without running out of fuel"
        instruct2="Good landing:<15m/s Great landing:<5m/s"
        inst1_font=pygame.font.Font(None,24)
        inst1_surf=inst1_font.render(instruct1,1,(255,255,255))
        screen.blit(inst1_surf,[50,550])
        inst2_font=pygame.font.Font(None,24)
        inst2_surf=inst1_font.render(instruct2,1,(255,255,255))
        screen.blit(inst2_surf,[20,575])
        pygame.display.flip()
    else:
        display_final()
    for event in pygame.event.get():
        if event.type==pygame.QUIT:
            running=False
        elif event.type==pygame.MOUSEBUTTONDOWN:
            held_down=True
        elif event.type==pygame.MOUSEMOTION:
            if held_down:
                myThrottle.rect.centery=event.pos[1]
                if myThrottle.rect.centery<300:
                    myThrottle.rect.centary==300
                if myThrottle.rect.cemtery>500:
                    myThrottle.rect.centery=500
pygame.quit()