def _add_exdate(vevent, instance):

    def dates_from_exdate(vdddlist):
        return [dts.dt for dts in vevent['EXDATE'].dts]

    if 'EXDATE' not in vevent:
        vevent.add('EXDATE', instance)
    else:
        if not isinstance(vevent['EXDATE'], list):
            exdates = dates_from_exdate(vevent['EXDATE'])
        else:
            exdates = list()
            for vddlist in vevent['EXDATE']:
                exdates.append(dates_from_exdate(vddlist))
        exdates += [instance]
        vevent.pop('EXDATE')
        vevent.add('EXDATE', exdates)
Finds output plugin with a given name.
dataset/ETHPy150Open pimutils/khal/khal/khalendar/aux.py/_add_exdate--crossover with--dataset/ETHPy150Open google/grr/grr/tools/export_plugins/plugin.py/OutputPluginBasedExportPlugin._FindOutputPluginByName