def info_formatter(info):
    """Produce a sequence of formatted lines from info.

    `info` is a sequence of pairs (label, data).  The produced lines are
    nicely formatted, ready to print.

    """
    label_len = max([len(l) for l, _d in info])
    for label, data in info:
        if data == []:
            data = "-none-"
        if isinstance(data, (list, tuple)):
            prefix = "%*s:" % (label_len, label)
            for e in data:
                yield "%*s %s" % (label_len+1, prefix, e)
                prefix = ""
        else:
            yield "%*s: %s" % (label_len, label, data)
Produce a sequence of formatted lines from info.

    `info` is a sequence of pairs (label, data).  The produced lines are
    nicely formatted, ready to print.