Added sparkSql/RddDataframeConversion.py

Author: Pedro Bernardo

sparkSql/RddDataframeConversion.py

@@ -0,0 +1,39 @@
+from pyspark.sql import SparkSession
+from commons.Utils import Utils
+
+def getColNames(line: str):
+    splits = Utils.COMMA_DELIMITER.split(line)
+    return [splits[2], splits[6], splits[9], splits[14]]
+
+def mapResponseRdd(line: str):
+    splits = Utils.COMMA_DELIMITER.split(line)
+    double1 = None if not splits[6] else float(splits[6])
+    double2 = None if not splits[14] else float(splits[14])
+    return splits[2], double1, splits[9], double2
+
+if __name__ == "__main__":
+
+    session = SparkSession.builder.appName("StackOverFlowSurvey").master("local").getOrCreate()
+    sc = session.sparkContext
+    sc.setLogLevel("ERROR")
+
+    lines = sc.textFile("in/2016-stack-overflow-survey-responses.csv")
+
+    colNames = lines \
+        .filter(lambda line: Utils.COMMA_DELIMITER.split(line)[2] == "country") \
+        .map(getColNames)
+
+    responseRDD = lines \
+        .filter(lambda line: not Utils.COMMA_DELIMITER.split(line)[2] == "country") \
+        .map(mapResponseRdd)    
+
+    responseDataFrame = responseRDD.toDF(colNames.collect()[0])
+
+    print("=== Print out schema ===")
+    responseDataFrame.printSchema()
+
+    print("=== Print 20 records of responses table ===")
+    responseDataFrame.show(20)
+
+    for response in responseDataFrame.rdd.collect():
+        print(response)