import pygame
from pygame.locals import *
import sys


class Entity(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)

class Hero(Entity):
    def __init__(self, x, y):
        super(Hero, self).__init__()
        self.image = pygame.Surface((20, 50))
        self.image.fill((255, 0, 255))
        self.rect = self.image.get_rect()
        sprites.add(self)
        self.change_x = 0
        self.change_y = 0
        self.pos = ()

    def update(self, key):
        if key[K_w]:
            self.change_y += -5

        if key[K_s]:
            self.change_y += 5

        self.rect.y += self.change_y






pygame.init()

screen = pygame.display.set_mode((800, 600))

sprites = pygame.sprite.Group()

player = Hero(50, 500)


running = True

while running:
    key = pygame.key.get_pressed()
    for event in pygame.event.get():
        if event.type == QUIT or key[K_ESCAPE]:
            running = False

    sprites.update(key)

    for sprite in sprites:
        screen.blit(sprite.image, (sprite.rect.x, sprite.rect.y))
    pygame.display.flip()

pygame.quit()
sys.exit()