老师， 你好，
使用spark-submit 提交rdd任务 都正常， 但是提交 spark Streaming 就包如下错误， 可能是什么原因呢，

root@spark:bin]$ ./spark-submit /root/app/spark/spark-2.3.1-bin-2.6.0-cdh5.7.0/examples/src/main/python/wordcount.py localhost 9999
20/03/08 16:41:25 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform… using builtin-java classes where applicable
Usage: wordcount
log4j:WARN No appenders could be found for logger (org.apache.spark.util.ShutdownHookManager).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Using Spark’s default log4j profile: org/apache/spark/log4j-defaults.properties