My apologies if this is really obvious but I honestly have no clue what’s happening.
I call a function with a list entry as one of the parameters. Inside the function, I modify the values because I need to, and somehow the original list ends up being changed even though never referenced?

objects = [[0, [5, 0.3, 1.2], 1, (255, 0, 0)], [0, [3, 0, -1.5], 1, (0, 0, 255)]]
    """Obj Index:
    [type, pos, size, colour]
    0: Cube"""
    running = True
    FOV = 70
    camerapos = [0, 0, 0]
    while running:
        print(camerapos)
        screen.fill((0, 0, 0))
        for event in pygame.event.get():
            if event.type == pygame.QUIT: running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_w:
                    camerapos[0] += 0.02
                if event.key == pygame.K_s:
                    camerapos[0] -= 0.02
                if event.key == pygame.K_a:
                    camerapos[2] -= 0.02
                if event.key == pygame.K_d:
                    camerapos[2] += 0.02
        for i in objects:
            drawShape(i, FOV, screen, camerapos)

def drawShape(data, FOV, screen, camerapos):
    if data[0] == 0:
        for i in range(len(data[1])):
            data[1][i] -= camerapos[i]

When I press any of WASD, the camera starts moving and doesnt stop when I lift my finger. Pressing the key again just makes it speed up, pressing the opposite key slows it down.
Also how do I make it so that I can hold a key down to move? It used to work like this but now doesn’t and I cant find anything on it.