def timedelta_to_str(aTimedelta):
    """ a conversion function for time deltas to string in the form
    DD:HH:MM:SS
    """
    days = aTimedelta.days
    temp_seconds = aTimedelta.seconds
    hours = int(temp_seconds / 3600)
    minutes = int((temp_seconds - hours * 3600) / 60)
    seconds = temp_seconds - hours * 3600 - minutes * 60
    return '%d %02d:%02d:%02d' % (days, hours, minutes, seconds)
a conversion function for time deltas to string in the form
    DD:HH:MM:SS