def shift_pos(pos, label_shift):
    """shift a pos by (sx, xy) pixels"""
    shiftx = label_shift[0]
    shifty = label_shift[1]
    pos2 = pos.copy()
    for key, position in pos2.items():
        pos2[key] = ( position[0] + shiftx, position[1] + shifty)
        
    return pos2