def render_string(s, f, colour, background, antialiasing = True):
    """
    Create pygame.Surface and pygame.Rect objects for a string, using a
    given font (f) and colour.
    
    Parameters:
        s: the string to render.
        f: the font in which to render s.
        colour: the colour of text to use, expressed as an RGB list or tuple.
        background: the background colour.
    
    Keyword Parameters:
        antialiasing: indicates whether text is rendered with antialiasing;
            defaults to True.
    
    Returns:
        s: the pygame.Surface object.
        r: the pygame.Rect object.
    """
    s = f.render(s, antialiasing, colour, background)
    r = s.get_rect()
    return s, r