title: changing image in pygame
body: <p>I'm making a game for school that's a mini RPG thing. I have tried to code it so that the image changes, but my code doesn't work. I've looked through many articles, and I have not found a working solution for my case. Have I done something wrong in a specific area, or have I started the code at a completely incorrect angle? Help is greatly appreciated.</p>
  
  <pre><code>import pygame
  
  pygame.init()
  
  width = 800
  height = 600
  
  black = (0, 0, 0)
  white = (255, 255, 255)
  red = (255, 0, 0)
  green = (0, 255, 0)
  blue = (0, 0, 255)
  
  gameDisplay = pygame.display.set_mode((width, height))
  pygame.display.set_caption('8Bit Adventure Time!')
  clock = pygame.time.Clock()
  
  finnImg = [pygame.image.load('AdvManRight.png'), pygame.image.load('AdvManLeft.png')]
  finnImg_current = finnImg[0]
  
  finnwidth = 115
  finnheight = 201
  
  def Finn(x, y):
      gameDisplay.blit(finnImg_current, (x, y))
  
  def game_loop():
  
      x = ((width/2) - (finnwidth/2))
      y = ((height/2) - (finnheight/2))
  
  
      gameExit = False
  
      while not gameExit:
  
          x_change = 0
          y_change = 0
  
          gameDisplay.fill(white)
          Finn(x,y)
  
          for event in pygame.event.get():
  
              if event.type == pygame.QUIT:
                  pygame.quit()
                  quit()
  
              if event.type == pygame.KEYDOWN:
                  if event.key == pygame.K_LEFT:
                      finnImg_current = finnImg[0]
                      pygame.display.update() #the image is supposed to change here, but nothing happens...
                      x_change = -40
                  if event.key == pygame.K_RIGHT:
                      finnImg_current = finnImg[1]
                      pygame.display.update() #the image is supposed to change here, but nothing happens...
                      x_change = 40
                  if event.key == pygame.K_UP:
                      y_change = -40
                  if event.key == pygame.K_DOWN:
                      y_change = 40
  
          x += x_change
          y += y_change
  
          pygame.display.update()
          clock.tick(60)
  
  game_loop()
  pygame.quit()
  quit()
  </code></pre>