Column alias after groupBy in pyspark

You can use agg instead of calling max method:

from pyspark.sql.functions import max

joined_df.groupBy(temp1.datestamp).agg(max("diff").alias("maxDiff"))

Similarly in Scala

import org.apache.spark.sql.functions.max

joined_df.groupBy($"datestamp").agg(max("diff").alias("maxDiff"))

or

joined_df.groupBy($"datestamp").agg(max("diff").as("maxDiff"))