Pygame真实跳跃

Question

现在我正试图用python制作好看的跳跃动画，但现在太快了。有没有办法在跳跃中加入重力

import pygame
W, H = 600, 600
playerx1 = 300
playery1 = 300
pygame.init()
screen = pygame.display.set_mode((W, H))
bg = pygame.image.load('bg.jpg').convert()
player1 = pygame.image.load('player1.png').convert_alpha()

velocity = [-7.5, -7, -6.5, -6, -5.5, -5, -4.5, -4, -3.5, -3, -2.5, -2,
            -1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5,
     5, 5.5, 6, 6.5, 7, 7.5]

i = 0


def player1blit():
    global playery1, i
    playery1 += velocity[i]
    screen.blit(player1,(playerx1, playery1))
    i+=1
    if i>(len(velocity)-1):
        i=0


def main():
    global playery1, playerx1, jump_status, velocity
    running = True
    while running:
        pygame.mouse.set_visible(False)
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
        screen.blit(bg, (0, 0))
        player1blit()



        pygame.display.flip()
        pygame.display.update()

现在跳跃是有效的，但它是非常人工的