pySpark writerStream未将输出显示到Jupyter实验室的控制台

from pyspark.sql import SparkSession
from pyspark.streaming import StreamingContext

spark = SparkSession.builder.appName("StreamingExample").getOrCreate()
ssc = StreamingContext(spark.sparkContext, 1)

spark.sparkContext.setLogLevel("WARN")

def output_func(rdd):
    rdd.foreach(lambda record: print(record))

lines = ssc.socketTextStream("localhost", 9999)
lines.foreachRDD(output_func)

ssc.start()
ssc.awaitTermination()