Set Path Variables for Python
To change the Python executable used by a Livy session, follow the instructions for your version of Python.
pyspark
Livy reads the path from the PYSPARK_PYTHON environment variable (this
            is the same as PySpark).
- 
               If Livy is running in localmode, simply set the environment variable (this is the same as PySpark).
- 
               If the Livy session is running in yarn-clustermode, setspark.yarn.appMasterEnv.PYSPARK_PYTHONin theSparkConffile, so that the environment variable is passed to the driver.
pyspark3
Livy reads the path from environment variable PYSPARK3_PYTHON.
- 
               If Livy is running in localmode, simply set the environment variable.
- 
               If the Livy session is running in yarn-clustermode, setspark.yarn.appMasterEnv.PYSPARK3_PYTHONinSparkConffile, so that the environment variable is passed to the driver.

