PySpark Select First Row of Each Group?

In PySpark select/find the first row of each group within a DataFrame can be get by grouping the data using window partitionBy() function and running row_number() function over window partition. let's see with an example. 1. Prepare Data & DataFrame Before we start let's create the PySpark DataFrame with 3…

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Spark RDD fold() function example

In this tutorial, you will learn fold syntax, usage and how to use Spark RDD fold() function in order to calculate min, max, and a total of the elements with Scala example and the same approach could be used for Java and PySpark (python). Syntax def fold(zeroValue: T)(op: (T, T)…

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Spark RDD reduce() function example

Spark RDD reduce() aggregate action function is used to calculate min, max, and total of elements in a dataset, In this tutorial, I will explain RDD reduce function syntax and usage with scala language and the same approach could be used with Java and PySpark (python) languages. Syntax def reduce(f:…

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Spark RDD aggregate() operation example

In this tutorial, you will learn how to aggregate elements using Spark RDD aggregate() action to calculate min, max, total, and count of RDD elements with scala language, and the same approach could be used for Java and PySpark (python). RDD aggregate() Syntax def aggregate[U](zeroValue: U)(seqOp: (U, T) ⇒ U,…

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Spark DataFrame Select First Row of Each Group?

In this Spark article, I've explained how to select/get the first row, min (minimum), max (maximum) of each group in DataFrame using Spark SQL window functions and Scala example. Though I've explained here with Scala, the same method could be used to working with PySpark and Python. 1. Preparing Data…

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