gistfile1.py

def _rangesOverlap(start1, end1, start2, end2):
    """
    Check if [start1, end1) and [start2, end2) overlap.

    @type start1: L{datetime.datetime}

    @type end1: L{datetime.datetime}

    @type start2: L{datetime.datetime}

    @type end2: L{datetime.datetime}

    @rtype: L{bool}
    """
    # This is not very good, because we can't handle dates outside of these
    # bounds, but hopefully that will never be a practical problem.
    _DATE_MIN = Time.fromDatetime(datetime(1, 1, 1, 0, 0, 0))
    _DATE_MAX = Time.fromDatetime(datetime(9999, 1, 1, 0, 0, 0))

    if start1 is None:
        start1 = _DATE_MIN
    if start2 is None:
        start2 = _DATE_MIN
    if end1 is None:
        end1 = _DATE_MAX
    if end2 is None:
        end2 = _DATE_MAX
    return (start1 <= start2 < end1) or (start2 <= start1 < end2)