Aapche flink:PythonAPI实现流式计算无法引入三方模块

想利用flink提供的PythonAPI实现流式计算,碰到下面无法导入三方包的问题.
通过flink安装包提供的shell命令执行Python脚本无法引用三方模块 ,但通过Python命令进入可以引入kafka模块
./bin/pyflink-stream.sh examples/python/streaming/word_count_bamboo.py

脚本详情:

from __future__ import absolute_import
from org.apache.flink.streaming.api.functions.source import SourceFunction
from org.apache.flink.api.common.functions import FlatMapFunction, ReduceFunction
from org.apache.flink.api.java.functions import KeySelector
from org.apache.flink.streaming.api.windowing.time.Time import milliseconds

from kafka import KafkaProducer
from kafka import KafkaConsumer 
from kafka.structs import TopicPartition
from kafka.errors import KafkaError

class Kafka_Consumer():
    def __init__(self, kafkahost, kafkaport, kafkatopic,groupid):
        self.kafkaHost = kafkahost
        self.kafkaPort = kafkaport
        self.kafkaTopic = kafkatopic
        self.groupId = groupid
        self.consumer = kafkaConsumer(self.kafkaTopic,
                                      group_id = self.groupId,
                                      bootstrap_servers = '{kafka_host}:{kafka_port}'.format(
                                              kafka_host=self.kafkaHost,
                                              kafka_port=self.kafkaPort))


class Tokenizer(FlatMapFunction):
    def flatMap(self, value, collector):
        for word in value.lower().split():
            collector.collect((1, word))


class Selector(KeySelector):
    def getKey(self, input):
        return input[1]


class Sum(ReduceFunction):
    def reduce(self, input1, input2):
        count1, word1 = input1
        count2, word2 = input2
        return (count1 + count2, word1)

def main(factory):
    env = factory.get_execution_environment()
    env.create_python_source(Kafka_Consumer("172.19.78.11", 9092, "demo", 'test-python')) \
        .flat_map(Tokenizer()) \
        .key_by(Selector()) \
        .time_window(milliseconds(50)) \
        .reduce(Sum()) \
        .output()
    env.execute()