Python - How do I create a tile based movement with non integer movement? : everything is in the title, I know how to create a tile based movement and create non integer movement but not both together.

Here is what I aldready done :

    self.acc = vec(0 ,0)
    keystate = pygame.key.get_pressed()
    if keystate[pygame.K_UP]:
    	self.acc.y = -PLAYER_ACC
    if keystate[pygame.K_DOWN]:
    	self.acc.y = PLAYER_ACC
    if keystate[pygame.K_LEFT]:
    	self.acc.x = -PLAYER_ACC
    if keystate[pygame.K_RIGHT]:
    	self.acc.x = PLAYER_ACC
    self.acc += self.vel * PLAYER_FRICTION
    self.vel += self.acc
    if abs(self.vel.x) < 0.1:
    	self.vel.x = 0
    if abs(self.vel.y) < 0.1:
    	self.vel.y = 0
    self.pos += self.vel * self.game.dt
    self.rect.center = self.pos

Thank you.