spark编程python实例ValueError: Cannot run multiple SparkContexts at once; existing SparkContext(app=PySparkShell, master=local[])1.pyspark在jupyter notebook中开发,测试,提交1.1.启动下载应用,将应用下载为.py文件(默认notebook后缀是.ipynb)2.在shell中提交应用3.遇到的错误及解决ValueError: Cannot run...