def timeSlice(requestContext, seriesList, startSliceAt, endSliceAt='now'):
    results = []
    start = time.mktime(parseATTime(startSliceAt).timetuple())
    end = time.mktime(parseATTime(endSliceAt).timetuple())

    for slicedSeries in seriesList:
        slicedSeries.name = 'timeSlice(%s, %s, %s)' % (slicedSeries.name,
                                                       int(start), int(end))
        curr = time.mktime(requestContext["startTime"].timetuple())
        for i, v in enumerate(slicedSeries):
            if v is None or curr < start or curr > end:
                slicedSeries[i] = None
            curr += slicedSeries.step
        results.append(slicedSeries)
    return results
Takes one metric or a wildcard metric, followed by a quoted
dataset/ETHPy150Open brutasse/graphite-api/graphite_api/functions.py/timeSlice