def countSeries(requestContext, *seriesLists):
    """
    Draws a horizontal line representing the number of nodes found in the
    seriesList.

    Example::

        &target=countSeries(carbon.agents.*.*)

    """
    if not seriesLists or not any(seriesLists):
        series = constantLine(requestContext, 0).pop()
        series.pathExpression = "countSeries()"
    else:
        seriesList, start, end, step = normalize(seriesLists)
        name = "countSeries(%s)" % formatPathExpressions(seriesList)
        values = (int(len(row)) for row in zip_longest(*seriesList))
        series = TimeSeries(name, start, end, step, values)
        series.pathExpression = name

    return [series]

    Draws a horizontal line representing the number of nodes found in the
    seriesList.

    Example::

        &target=countSeries(carbon.agents.*.*)

    
graphite_api/functions.py