Setting the colorkey doesn't make that color transparent (Python/Pygame)

Setting the colorkey doesn't make that color transparent (Python/Pygame)

As said in the title, I am having trouble making one color transparent on
a sprite that I have. I set the colorkey to white, but the white spaces on
the sprite do not become transparent.
Here's what I have:
player_image = pygame.image.load("blanksprite.png").convert()
player_image.set_colorkey(white)
screen.blit(player_image, [x,y])