This post explains how to add constant columns to PySpark DataFrames with lit and typedLit. You’ll see examples where these functions are useful and when these functions are invoked implicitly. […]
This blog post shows you how to gracefully handle null in PySpark and how to avoid null input errors. Mismanaging the null case is a common source of errors and […]
This post explains how to create a SparkSession with getOrCreate and how to reuse the SparkSession with getActiveSession. You need a SparkSession to read data stored in files, when manually […]
This post explains how to write a Dask DataFrame to CSV files. You’ll see how to write CSV files, customize the filename, change the compression, and append files to an […]
Dask DataFrames are composed of multiple partitions and are outputted as multiple files, one per partition, by default. This post explains the different approaches to write a Dask DataFrame to […]
This post explains how Spark registers native functions internally and the public facing APIs for you to register your own functions. Registering native functions is important if you want to […]
This post shows you how to select a subset of the columns in a DataFrame with select. It also shows how select can be used to add and rename columns. […]
This post explains how to filter values from a PySpark array column. It also explains how to filter DataFrames with array columns (i.e. reduce the number of rows in a […]
Multiple PySpark DataFrames can be combined into a single DataFrame with union and unionByName. union works when the columns of both DataFrames being joined are in the same order. It […]
This post shows the different ways to combine multiple PySpark arrays into a single array. These operations were difficult prior to Spark 2.4, but now there are built-in functions that […]