def __format_exposuretime_tuple(_time):
    """format ExposureTime tuple to short printable string
    fractions over or equal 1 second are marked with s, e.g. 8s
    fractions below 1 second are broken down to the divisor,
    this is a bit incorrect but short and common e.g. in cameras
    (and we want to have a short string)
    """
    if (isinstance(_time,tuple)):
        numerator = _time[0]
        divisor = _time[1]
    else:
        numerator=_time.numerator
        divisor=_time.denominator
    if numerator % 10 == 0 and divisor % 10 == 0:
        # change 10/1250 to 1/125
        numerator = numerator // 10
        divisor = divisor // 10

    if divisor == 1:
        # change 6/1 -> 6s
        # fractions => 1s with s for seconds
        _string = f"{numerator}s"
    else:
        # change 1/125 -> 125
        _string = f"{divisor}"
    return _string