list append not working (list always empty)

Question

I'm making a game and I created a loop in a class that creates a list with every sprite I need from my sprite sheet.

The problem is that when I try to blit an element of the list, I always get this error: IndexError: list index out of range

Here's the code of the function in the class (simplified):

    def sprites(self):
        i = 1
        boxwidth = 0
        boxwidthend = False
        sprites = []
        
        for i in range(1,0,5):
            while i <= 2:
                boxheight = 0
                spritesurface = pygame.Surface((self.width, self.heightside), pygame.SRCALPHA)
                spritesurface.blit(self.type, (0,0), (0 + boxwidth, 0, self.width, self.heightside))
                sprite = pygame.transform.scale(spritesurface, (self.width * self.scale, self.heightside * self.scale))
                sprites.append(sprite)

            while i <= 5:
                boxheight = 49
                if boxwidthend == False:
                    boxwidth = 0
                    boxwidthend = True
                spritesurface = pygame.Surface((self.width, self.heightup), pygame.SRCALPHA)
                spritesurface.blit(self.type, (0,0), (0 + boxwidth, boxheight, self.width, self.heightup))
                sprite = pygame.transform.scale(spritesurface, (self.width * self.scale, self.heightup * self.scale))
                sprites.append(sprite)
            boxwidth += 25
            i += 1

      return sprites

and here's the main code section (simplified):

sprites_class = GetSprites("human", 3)
spritelist = sprites_class.sprites()
while True:
   ROOT.blit(spritelist[3], (playermovement.x, playermovement.y))

Answer 1

Summarizing the comments:

1. Range takes three parameters

   • start Optional. An integer number specifying at which position to start. Default is 0
   • stop Required. An integer number specifying at which position to stop (not included).
   • step Optional. An integer number specifying the incrementation. Default is 1

   So if you want to loop numbers 1 through 5, all you need is Range(6) as the optional start parameter defaults to 0 and the optional step parameter defaults to 1.

2. while i<=2: will result in an infinite loop as there is no way for the value of i to change inside the loop. Once you enter it, it will go on forever. Instead you want an if and elif

---

def sprites(self):
    
    boxwidth = 0
    boxwidthend = False
    sprites = []
    
    for i in range(6):
        if i <= 2:
            print("i <= 2")
            boxwidth += 1
            boxheight = 0
            spritesurface = pygame.Surface((self.width, self.heightside), pygame.SRCALPHA)
            spritesurface.blit(self.type, (0,0), (0 + 25 * boxwidth, 0, self.width, self.heightside))
            sprite = pygame.transform.scale(spritesurface, (self.width * self.scale, self.heightup * self.scale))
            sprites.append(sprite)

        elif i <= 5:
            print("i > 2")
            boxheight = 48
            if boxwidthend == False:
                boxwidth = 0
                boxwidthend = True
            spritesurface = pygame.Surface((self.width, self.heightup), pygame.SRCALPHA)
            spritesurface.blit(self.type, (0,0), (0 + 25 * boxwidth, boxheight, self.width, self.heightup))
            sprite = pygame.transform.scale(spritesurface, (self.width * self.scale, self.heightup * self.scale))
            sprites.append(sprite)
    return sprites