'Scala: How can I replace value in Dataframes using scala
For example I want to replace all numbers equal to 0.2 in a column to 0. How can I do that in Scala? Thanks
Edit:
|year| make|model| comment |blank|
|2012|Tesla| S | No comment | |
|1997| Ford| E350|Go get one now th...| |
|2015|Chevy| Volt| null | null|
This is my Dataframe I'm trying to change Tesla in make column to S
Solution 1:[1]
Spark 1.6.2, Java code (sorry), this will change every instance of Tesla to S for the entire dataframe without passing through an RDD:
dataframe.withColumn("make", when(col("make").equalTo("Tesla"), "S")
.otherwise(col("make")
);
Edited to add @marshall245 "otherwise" to ensure non-Tesla columns aren't converted to NULL.
Solution 2:[2]
Building off of the solution from @Azeroth2b. If you want to replace only a couple of items and leave the rest unchanged. Do the following. Without using the otherwise(...) method, the remainder of the column becomes null.
import org.apache.spark.sql.functions._
val newsdf =
sdf.withColumn(
"make",
when(col("make") === "Tesla", "S").otherwise(col("make"))
);
Old DataFrame
+-----+-----+
| make|model|
+-----+-----+
|Tesla| S|
| Ford| E350|
|Chevy| Volt|
+-----+-----+
New Datarame
+-----+-----+
| make|model|
+-----+-----+
| S| S|
| Ford| E350|
|Chevy| Volt|
+-----+-----+
Solution 3:[3]
This can be achieved in dataframes with user defined functions (udf).
import org.apache.spark.sql.functions._
val sqlcont = new org.apache.spark.sql.SQLContext(sc)
val df1 = sqlcont.jsonRDD(sc.parallelize(Array(
"""{"year":2012, "make": "Tesla", "model": "S", "comment": "No Comment", "blank": ""}""",
"""{"year":1997, "make": "Ford", "model": "E350", "comment": "Get one", "blank": ""}""",
"""{"year":2015, "make": "Chevy", "model": "Volt", "comment": "", "blank": ""}"""
)))
val makeSIfTesla = udf {(make: String) =>
if(make == "Tesla") "S" else make
}
df1.withColumn("make", makeSIfTesla(df1("make"))).show
Solution 4:[4]
df2.na.replace("Name",Map("John" -> "Akshay","Cindy" -> "Jayita")).show()
replace in class DataFrameNaFunctions of type [T](col: String, replacement: Map[T,T])org.apache.spark.sql.DataFrame
For running this function you must have active spark object and dataframe with headers ON.
Solution 5:[5]
import org.apache.spark.sql.functions._
val base_optin_email = spark.read.option("header","true").option("delimiter",",").schema(schema_base_optin).csv(file_optin_email).where("CPF IS NOT NULL").
withColumn("CARD_KEY", lit(translate( translate(col("cpf"), ".", ""),"-","")))
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | ChrisOdney |
| Solution 2 | Xavier Guihot |
| Solution 3 | Al M |
| Solution 4 | Akshay Pandya |
| Solution 5 | Juan Diego Lozano |
