def formatList(container, items_to_place):

    """

    Receives a container and a list with the number of items to
    be placed on it. Returns a string representing one line of
    the solution file.

    """

    s = '{0:3d},'.format(container.getUid())

    for nit in items_to_place:

        s += '{0:5d},'.format(nit)

    s += '\n'

    return s