Adding source code for chapter 8

Chapter8/rdd/rddtranform1.py

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+#rddtransform1.py: rdd tranformation function
+
+#please ignore next 2 statements if running directly in PySpark shell
+import time
+
+from pyspark.sql import SparkSession
+spark = SparkSession.builder.master("local[*]")\
+    .appName("RDD Test app")\
+    .getOrCreate()
+
+rdd1 = spark.sparkContext.textFile('sample.txt')
+#print(rdd1.getNumPartitions())
+rdd2 = rdd1.map(lambda lines: lines.lower())
+rdd3 = rdd1.map(lambda lines: lines.upper())
+
+print(rdd2.collect())
+print(rdd3.collect())
+
+time.sleep(60)