![]() ![]() This method saves you from having to write “ expr” every time you want to pass an expression. Spark offers a short form that brings great power - selectExpr. Scala and Python df.select(expr("ColumnName AS customName")) selectExpr For example, if we wanted to list the column under a different heading, here’s how we’d do it. The function expr is different from col and column as it allows you to pass a column manipulation. 6 ways to select a column df.select(df.col("ColumnName")) df.select(col("ColumnName")) df.select(column("ColumnName")) df.select(`ColumnName) df.select($"ColumnName") df.select(expr("ColumnName")) PySpark # Python from import expr, col, column # 4 ways to select a column df.select(df.ColumnName) df.select(col("ColumnName")) df.select(column("ColumnName")) df.select(expr("ColumnName")) expr Allows for Manipulation Here are several ways to select a column called “ ColumnName” from df. For this tutorial, assume a DataFrame has already been read as df. Package import .SparkSession import .functions.Selecting Columns in Spark (Scala & Python)Īpache Spark offers several methods to use when selecting a column. Let us now read a single file called Dataframe4.scala The Spark processing engine is built for speed, ease of use, and sophisticated analytics. Package import ._ class demo_HelloTest extends AnyFunSuite Īnd the first lines of the output will be Spark is an open-source parallel-processing framework that supports in-memory processing to boost the performance of big data analytics applications. You can create a file called HelloWorld.scala The first thing that we are going to do is do the My first Hello World in Scala with Spark. The next step is create new folder from the root src/main/scala/ If you want to change that, from the Insert imports on paste list, select Ask to confirm every insertion or Never to insert import statements manually. When you are pasting blocks of code that contain references to classes or static methods and fields that are not yet imported, the IDE automatically inserts the missing import statements. Select the Add unambiguous imports on the fly checkbox, and apply the changes. Take care in asking for clarification, commenting, and answering. LUSIFER is a new contributor to this site.
0 Comments
Leave a Reply. |