def hhmmss(ms):
    # s = 1000
    # m = 60000
    # h = 360000
    h, r = divmod(ms, 36000)
    m, r = divmod(r, 60000)
    s, _ = divmod(r, 1000)
    return ("%d:%02d:%02d" % (h,m,s)) if h else ("%d:%02d" % (m,s))

class AbListModel(QAbstractListModel):
    def __init__(self, *args, **kwargs):
        super(AbListModel, self).__init__(*args, **kwargs)
        self.abList = list()

    def data(self, index, role):
        if role == Qt.DisplayRole:
            ab = self.abList[index.row()]
            return f"{hhmmss(ab[0])} - {hhmmss(ab[1])}"

    def rowCount(self, index):
        return len(self.abList)