# -*- coding: utf-8 -*-
"""
author SparkByExamples.com
"""

from pyspark.sql import SparkSession

spark = SparkSession.builder.appName('SparkByExamples.com').getOrCreate()

data = [('James','Smith','M',3000),('Anna','Rose','F',4100),
  ('Robert','Williams','NA',6200),(None,'Rob','F',6200)
  
]

columns = ["firstname","lastname","gender","salary"]
df = spark.createDataFrame(data=data, schema = columns)
df.show()

df2=df.withColumn("salary", df.salary*3)
df2.show()

from pyspark.sql.functions import when
df3 = df.withColumn("gender", when(df.gender == "M","Male") \
      .when(df.gender == "F","Female") \
      .otherwise(df.gender))
df3.show()

df4=df.withColumn("salary",df.salary.cast("String"))
df4.printSchema()

df.createOrReplaceTempView("PER")
df5=spark.sql("select firstname,gender,salary*3 as salary from PER")
df5.show()