How do i create a single SparkSession in one file and reuse it other file

Question

I have two py files

com/demo/DemoMain.py
com/demo/Sample.py

In both of the above files i am recreating the SparkSession object , In Pyspark,how do i create a Sparksession in one file and reuse it in other py files . In Scala it is easily possible by creating in one object and import that it everywhere

DemoMain.py

from pyspark.sql.types import StringType, StructType, StructField
 from pyspark.sql import SparkSession
from pyspark.sql import Row

def main():

 spark = SparkSession \
    .builder \
    .appName("Python Spark SQL basic example") \
    .getOrCreate()

sc = spark.sparkContext
data=["surender,34","ajay,21"]
lines = sc.parallelize(data)
parts = lines.map(lambda l: l.split(","))
people = parts.map(lambda p: Row(name=p[0], age=int(p[1])))
df=spark.createDataFrame(people)
df.show()

if __name__ == '__main__':
 main()

sample.py

from pyspark.sql import SparkSession

spark = SparkSession \
.builder \
.appName("Python Spark SQL basic example") \
.getOrCreate()

rdd = spark.sparkContext.parallelize(["surender","raja"])
rdd.collect()