#1
pyspark --jars file1.jar,file2.jar

#2
./bin/spark-submit --jars xxx.jar your_spark_script.py

#3
SPARK_CLASSPATH='/path/xxx.jar:/path/xx2.jar' your_spark_script.py

#4 using spark context

conf = SparkConf().set("spark.jars", "/path-to-jar/spark-streaming-kafka-0-8-assembly_2.11-2.2.1.jar")

sc = SparkContext( conf=conf)