How to use the influxdb.InfluxDBClient.from_dsn function in influxdb

def init(dsn):
    from influxdb import InfluxDBClient
    global client
    global thread
    global queue
    print "Initing InfluxDB"
    client = InfluxDBClient.from_dsn(dsn)
    print dsn
    print "Inited InfluxDB"
    queue = Queue.Queue(10000)
    thread = threading.Thread(target = influxWorker)
    thread.start()

def process_eni_metrics(
        stream_eni, myips, stream,
        start, end, period, sample_size,
        resolver, sink_uri):
    """ENI flow stream processor that rollups, enhances,
       and indexes the stream by time period."""
    stats = Counter()
    period_counters = flow_stream_stats(myips, stream, period)
    client = InfluxDBClient.from_dsn(sink_uri)
    resource = resolver.resolve_resource(stream_eni)
    points = []

    for period in sorted(period_counters):
        pc = period_counters[period]
        pd = datetime.fromtimestamp(period)

        for t in ('inbytes', 'outbytes'):
            tpc = pc[t]
            ips = [ip for ip, _ in tpc.most_common(sample_size)]
            resolved = resolver.resolve(ips, pd - timedelta(900), pd + timedelta(900))
            logical_counter = rollup_logical(tpc, resolved, ('app', 'env'))
            for (app, env), v in logical_counter.items():
                p = {}
#                rinfo = resolved.get(ip, {})
                p['fields'] = {'Bytes': v}

def __init__(self, name=None):

        self.client = InfluxDBClient.from_dsn(INFLUXDB_DSN, timeout=2)

        dbname = INFLUXDB_DATABASE or self.client._database
        try:
            if dbname:
                self.client.switch_database(dbname)
                self.client.create_database(dbname)
        except Exception as e:
            LOG.error('InfluxDB: ERROR - %s' % e)

        super(InfluxDBWrite, self).__init__(name)