def strip_from_sheet(sheet, start, size, columns, rows=1):
    """
    Strips individual frames from a sprite sheet given a start location,
    sprite size, and number of columns and rows.
    """
    frames = []
    for j in range(rows):
        for i in range(columns):
            location = (start[0]+size[0]*i, start[1]+size[1]*j)
            frames.append(sheet.subsurface(pg.Rect(location, size)))
    return frames