Pyspark when function. value: The value to return when the condition is true. In this article, I’ve explained the concept of window functions, syntax, and finally how to use them with PySpark SQL and PySpark DataFrame API. Apache Spark Tutorial - Apache Spark is an Open source analytical processing engine for large-scale powerful distributed data processing applications. select method over the DataFrame and as its argument, type-in the function_name along with its parameter as the specific column you want to apply the function on. Limitations, real-world use cases, and alternatives. If the regex did not match, or the specified group did not match, an empty string is returned. col(col) [source] # Returns a Column based on the given column name. We can use CASE and WHEN similar to SQL using expr or selectExpr. Use . Similarly, PySpark SQL Case When statement can be used on DataFrame, below are some of the examples of using with withColumn(), pyspark. May 19, 2021 · In this article, we'll discuss 10 PySpark functions that are most useful and essential to perform efficient data analysis of structured data. . Learn how to implement if-else conditions in Spark DataFrames using PySpark. addStreamingListener pyspark. This expression is then passed to the DataFrame's filter() (or where()) method, allowing PySpark to efficiently select only the rows where the condition evaluates to True. coalesce # pyspark. If a String used, it should be in a default format that can be cast to date. functions to work with DataFrame and SQL queries. 1. functions as F def Oct 22, 2022 · It also provides the Pyspark shell for real-time data analysis. How would you implement a custom transformation with a PySpark UDF - when to use UDFs vs native Spark SQL functions and how to keep performance acceptable? 𝗜 𝗵𝗮𝘃𝗲 What I learned today: Difference between PySpark vs Pandas and when to use each Performing complex joins (inner, left, right outer) Using window functions for running totals and rankings Creating Start your data engineering journey with this PySpark Cheat Sheet – a quick reference guide covering essential PySpark commands every beginner, aspiring Data Engineer and Developer should know The isNotNull() function returns a boolean expression (True/False) for every row, indicating whether the value in that specific column is non-null. This article will explore useful PySpark functions with scenario-based examples to understand them better. withColumn("device Feb 6, 2024 · This recipe is your go-to guide for mastering PySpark When and Otherwise function, offering a step-by-step guide to elevate your data skills. When is a SQL function with Column as the return Type? Jun 8, 2016 · Very helpful observation when in pyspark multiple conditions can be built using & (for and) and | (for or). A pattern could be for instance dd. when takes a Boolean Column as its condition. Dec 10, 2019 · how to use a pyspark when function with an or condition Asked 5 years, 5 months ago Modified 5 years, 5 months ago Viewed 3k times pyspark. when and pyspark. StreamingContext Mar 24, 2023 · Conditional functions in PySpark refer to functions that allow you to specify conditions or expressions that control the behavior of the function. What You'll Do Set shared default configurations. Data engineers reach for PySpark when their work goes beyond what Spark SQL can express cleanly — applying custom cleansing logic with Python libraries, calling user-defined functions that wrap business rules or ML models, or scheduling multi-step transformations that mix procedural code with DataFrame operations. Nov 13, 2023 · This tutorial explains how to use WHEN with an AND condition in PySpark, including an example. In PySpark, the when () function from the pyspark. to_timestamp(col, format=None) [source] # Converts a Column into pyspark. resetTerminated pyspark. array(*cols) [source] # Collection function: Creates a new array column from the input columns or column names. otherwise(value) [source] # Evaluates a list of conditions and returns one of multiple possible result expressions. Column ¶ Evaluates a list of conditions and returns one of multiple possible result expressions. when is available as part of pyspark. Nov 13, 2023 · This tutorial explains how to use the when function with OR conditions in PySpark, including an example. Define the function. DataFrame. 5 days ago · Data engineers reach for PySpark when their work goes beyond what Spark SQL can express cleanly — applying custom cleansing logic with Python libraries, calling user-defined functions that wrap business rules or ML models, or scheduling multi-step transformations that mix procedural code with DataFrame operations. Itshould start with the keyword and the conditions . coalesce() to combine multiple columns into one, and how to handle null values in the new column by assigning a default value using the lit() function. otherwise() is not invoked, None is returned for unmatched conditions. If all values are null, then null is returned. And WHEN is a SQL function used to restructure the DataFrame in spark. Create a DataFrame. CASE and WHEN is typically used to apply transformations based up on conditions. When to use it and why. from_json(col, schema, options=None) [source] # Parses a column containing a JSON string into a MapType with StringType as keys type, StructType or ArrayType with the specified schema. This guide details which APIs are supported and their compatibility levels. If this condition is true, the function will return the specified value. otherwise () method. first # pyspark. PySpark supports most of the Apache Spa rk functional ity, including Spark Core, SparkSQL, DataFrame, Streaming, MLlib (Machine Learning), and MLlib (Machine Learning). kll_sketch_get_quantile_bigint pyspark. when () Examples The following are 30 code examples of pyspark. By default, it follows casting rules to pyspark. 3 days ago · Implement the Medallion Architecture (Bronze, Silver, Gold) in Databricks with PySpark — including schema enforcement, data quality gates, incremental processing, and production patterns. I will explain the most used JSON SQL functions with Python examples in this article. Jul 23, 2025 · Import PySpark module Import pandas_udf from pyspark. TimestampType if the format is omitted. Feb 6, 2024 · This recipe is your go-to guide for mastering PySpark When and Otherwise function, offering a step-by-step guide to elevate your data skills. It is similar to Python’s filter () function but operates on distributed datasets. 10x faster. Aug 25, 2022 · The same can be implemented directly using pyspark. This function allows users to specify different conditions and corresponding actions, similar to the “case when” statement in SQL. These functions help you parse, manipulate, and extract data from JSON columns or strings. Sep 23, 2025 · PySpark Date and Timestamp Functions are supported on DataFrame and SQL queries and they work similarly to traditional SQL, Date and Time are very important if you are using PySpark for ETL. substring(str, pos, len) [source] # Substring starts at pos and is of length len when str is String type or returns the slice of byte array that starts at pos in byte and is of length len when str is Binary type. Feb 3, 2026 · Window functions in PySpark allow you to perform calculations across a group of rows, returning results for each row individually. Note:In pyspark t is important to enclose every expressions within parenthesis () that combine to form the condition May 29, 2023 · PySpark - Multiple Conditions in When Clause: An Overview PySpark is a powerful tool for data processing and analysis, but it can be challenging to work with when dealing with complex conditional statements. first(col, ignorenulls=False) [source] # Aggregate function: returns the first value in a group. This is some code I've tried: import pyspark. Dec 5, 2022 · Conditional statements in PySpark Azure Databricks with step by step examples. column. 3 Spark Connect API. They are widely used for data transformations, ranking and analytics. Access real-world sample datasets to enhance your PySpark skills for data engineering roles. , over a range of input rows. coalesce(*cols) [source] # Returns the first column that is not null. broadcast pyspark. col # pyspark. Most of the commonly used SQL functions are either part of the PySpark Column class or built-in pyspark. regexp_replace(string, pattern, replacement) [source] # Replace all substrings of the specified string value that match regexp with replacement. awaitTermination pyspark. Jan 2, 2026 · PySpark Overview # Date: Jan 02, 2026 Version: 4. In this blog post, we will explore how to use the PySpark `when` function with multiple conditions to efficiently filter and transform data. functions module is used to perform conditional expressions within DataFrame transformations. It will return the first non-null value it sees when ignoreNulls is set to true. In other words, I'd like to get more than two outputs. Oct 13, 2025 · PySpark SQL provides several built-in standard functions pyspark. PySpark: processing data with Spark in Python Spark SQL CLI: processing data with SQL on the command line Declarative Pipelines: building data pipelines that create and maintain multiple tables API Docs: Spark Python API (Sphinx) Spark Scala API (Scaladoc) Spark Java API (Javadoc) Spark R API (Roxygen2) Spark SQL, Built-in Functions (MkDocs) PySpark AI Functions Starter Notebook Learn to use PySpark AI Functions by building a transformation workflow on a customer-review dataset. pyspark. functions import pandas_udf import pandas as pd @pandas_udf (StringType ()) def clean_email_fast (emails: pd. from pyspark. Introduction to PySpark DataFrame Filtering PySpark filter() function is used to create a new DataFrame by filtering the elements from an existing DataFrame based on the given condition or SQL expression. It is analogous to the SQL WHERE clause and allows you to apply filtering criteria to DataFrame rows Jan 28, 2026 · Learn how to use the when function with Python pyspark. These functions are commonly used in data pyspark. 1 Useful links: Live Notebook | GitHub | Issues | Examples | Community | Stack Overflow | Dev Mailing List | User Mailing List PySpark is the Python API for Apache Spark. Jul 12, 2021 · I need to use when and otherwise from PySpark, but instead of using a literal, the final value depends on a specific column. Mar 18, 1993 · pyspark. StreamingQueryManager. sql. Parameters condition: A condition that returns a boolean (True/False). otherwise function in Spark with multiple conditions Ask Question Asked 3 years, 5 months ago Modified 3 years, 5 months ago Spark: when function The when command in Spark is used to apply conditional logic to DataFrame columns. Sep 23, 2025 · PySpark Window functions are used to calculate results, such as the rank, row number, etc. Use the pandas_udf as the decorator. StreamingContext. All these PySpark Functions return Python pyspark. to_timestamp # pyspark. where() is an alias for filter(). It is analogous to the SQL WHERE clause and allows you to apply filtering criteria to DataFrame rows pyspark. Feb 18, 2020 · In this tutorial , We will learn about case when statement in pyspark with example. Series Snowpark Connect for Spark compatibility is defined by its execution behavior when running a Spark application that uses the Pyspark 3. Jan 28, 2026 · Learn how to use the when function with Python Mar 27, 2024 · In PySpark, the JSON functions allow you to work with JSON data within DataFrames. Jul 10, 2025 · PySpark expr() is a SQL function to execute SQL-like expressions and to use an existing DataFrame column value as an expression argument to Pyspark built-in functions. Oct 16, 2024 · when (), otherwise () when function in PySpark is used for conditional expressions, similar to SQL’s CASE WHEN clause. filter # DataFrame. date_format(date, format) [source] # Converts a date/timestamp/string to a value of string in the format specified by the date format given by the second argument. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. A practical example demonstrates how to implement these functions to categorize gender data in a DataFrame. Nov 1, 2019 · Pyspark SQL expression versus when () as a case statement Ask Question Asked 6 years, 4 months ago Modified 6 years, 4 months ago PySpark when () and otherwise () Explained In this tutorial, you'll learn how to use the when() and otherwise() functions in PySpark to apply if-else style conditional logic directly to DataFrames. Equivalent to col. column pyspark. May 29, 2023 · PySpark - Multiple Conditions in When Clause: An Overview PySpark is a powerful tool for data processing and analysis, but it can be challenging to work with when dealing with complex conditional statements. kll_sketch_get_quantile_float pyspark Oct 13, 2025 · PySpark SQL provides several built-in standard functions pyspark. array # pyspark. I tried using the same logic of the concatenate IF function in Excel: df. 5. PySpark, the Python API for Apache Spark, offers a powerful set of functions and commands that enable efficient data processing and analysis at scale. functions module and is commonly used when dealing with nested structures like arrays, JSON, or structs. MM. Walk through all nine Fabric AI Functions on a Spark DataFrame. regexp_extract # pyspark. All these PySpark Functions return Aug 12, 2019 · 4. If we want to use APIs, Spark provides functions such as when and otherwise. 1 Overview Programming Guides Quick StartRDDs, Accumulators, Broadcasts VarsSQL, DataFrames, and DatasetsStructured StreamingSpark Streaming (DStreams)MLlib (Machine Learning)GraphX (Graph Processing)SparkR (R on Spark)PySpark (Python on Spark)Declarative Pipelines API Docs PythonScalaJavaRSQL, Built-in Functions Deploying Additional Resources To continue building expertise in the PySpark ecosystem, consider exploring the following advanced topics and related tutorials: How to handle null values and missing data using PySpark DataFrame functions. We can add our own condition in PySpark and use the when statement to use further. Conclusion: Leveraging Advanced Conditional Transformations The synergy between the PySpark when function and the bitwise OR operator (|) furnishes data professionals with an exceptionally powerful, scalable, and highly readable mechanism for defining intricate conditional logic across massive datasets. Partition Transformation Functions ¶ Aggregate Functions ¶ pyspark. functions May 28, 2024 · PySpark provides robust methods for applying conditional logic, primarily through the `when`, `case`, and `otherwise` functions. functions API, besides these PySpark also supports many other SQL functions, so in order to use these, you have to use Oct 7, 2025 · PySpark provides two transform () functions one with DataFrame and another in pyspark. regexp_extract(str, pattern, idx) [source] # Extract a specific group matched by the Java regex regexp, from the specified string column. date_format # pyspark. 1993’. Jun 8, 2016 · Very helpful observation when in pyspark multiple conditions can be built using & (for and) and | (for or). You can use multiple conditions with the when () function by chaining them together using the . Syntax May 13, 2024 · How to apply a function to a column in PySpark? By using withColumn(), sql(), select() you can apply a built-in function or custom function to a column. StreamingContext If you have a SQL background you might have familiar with Case When statementthat is used to execute a sequence of conditions and returns a value when the first condition met, similar to SWITH and IF THEN ELSE statements. API Reference # This page lists an overview of all public PySpark modules, classes, functions and methods. Recommended we covered different ways to filter rows in PySpark DataFrames, including using the ‘filter’, ‘where’ functions, SQL queries, and combining multiple filter. Aug 19, 2025 · 1. window(timeColumn, windowDuration, slideDuration=None, startTime=None) [source] # Bucketize rows into one or more time windows given a timestamp specifying column. Initialize the SparkSession. Build a compact dashboard and review common Write, run, and test PySpark code on Spark Playground’s online compiler. removeListener pyspark. Apr 10, 2023 · PySpark DataFrame uses SQL statements to work with the data. Column, value: Any) → pyspark. I am trying to use a "chained when" function. The function by default returns the first values it sees. If otherwise is not used together with when, None will be returned for unmatched conditions. otherwise # Column. Techniques for using SQL expressions directly within the PySpark filter method for enhanced query flexibility. Spark SQL Functions pyspark. Oct 18, 2022 · How to use when () . It is often used in conjunction with otherwise to handle cases where the condition is not met. Returns null, in the case of an unparsable string. These functions can also be used to convert JSON to a struct, map type, etc. PySpark Core This module is the foundation of PySpark. functions. When using PySpark, it's often useful to think "Column Expression" when you read "Column". 107 pyspark. kll_sketch_get_quantile_float pyspark Nov 21, 2022 · This blog post explains the when() and otherwise() functions in PySpark, which are used to transform DataFrame column values based on specified conditions, similar to SQL case statements. CASE Clause Description CASE clause uses a rule to return a specific result based on the specified condition, similar to if/else statements in other programming languages. Jun 24, 2024 · The PySpark library offers a powerful “when otherwise” function that can be used to mimic SQL’s “case when” statement in data analysis. Specify formats according to datetime pattern. They process data in batches, not row-by-row. Column. Load a public review sample and inspect rating and review-length patterns before enrichment. Logical operations on PySpark columns use the bitwise operators: & for and | for or ~ for not When combining these with comparison operators such as <, parenthesis are often needed. when(condition: pyspark. How do I use multiple conditions with pyspark. If Column. otherwise functions. from_json # pyspark. call_function pyspark. It is the preferred option when Sep 23, 2025 · PySpark Window functions are used to calculate results, such as the rank, row number, etc. kll_sketch_get_quantile_double pyspark. filter(condition) [source] # Filters rows using the given condition. substring # pyspark. Note:In pyspark t is important to enclose every expressions within parenthesis () that combine to form the condition pyspark. yyyy and could return a string like ‘18. This tutorial covers applying conditional logic using the when function in data transformations with example code. Mar 27, 2024 · Both PySpark & Spark AND, OR and NOT operators are part of logical operations that supports determining the conditional-based logic relation among the operands. It enables you to perform real-time, large-scale data processing in a distributed environment using Python. It provides support for Resilient Distributed Datasets (RDDs) and low-level operations, enabling distributed task execution and fault-tolerant data 5 days ago · Learn how to use file-based multimodal input, such as images, PDFs, and text files, with AI functions in Microsoft Fabric. May 28, 2024 · PySpark provides robust methods for applying conditional logic, primarily through the `when`, `case`, and `otherwise` functions. cast("timestamp"). awaitAnyTermination pyspark. It is part of the pyspark. when (). can be used. 03. Oct 13, 2025 · In PySpark, the explode() function is used to explode an array or a map column into multiple rows, meaning one row per element. It also provides a PySpark shell for interactively analyzing your Jul 18, 2025 · sum () Function collect () Function Core PySpark Modules Explore PySpark’s four main modules to handle different data processing tasks. pyspark. Jul 14, 2025 · In this article, I will explain how to use pyspark. Nov 1, 2019 · Pyspark SQL expression versus when () as a case statement Ask Question Asked 6 years, 4 months ago Modified 6 years, 4 months ago Jan 28, 2026 · Learn how to use the when function with Python Using CASE and WHEN Let us understand how to perform conditional operations using CASE and WHEN in Spark. All pattern letters of datetime pattern. streaming. TimestampType using the optionally specified format. PySpark coalesce () Function In PySpark, the coalesce() function is used to reduce the number of partitions in a DataFrame to a specified number. On top of Aug 19, 2025 · 1. Most of all these functions accept input as, Date type, Timestamp type, or String. when ()? Asked 10 years, 5 months ago Modified 5 years, 4 months ago Viewed 167k times Jan 29, 2026 · Learn how to use the when function with Python Spark: when function The when command in Spark is used to apply conditional logic to DataFrame columns. types. col pyspark. This is similar to the IF-ELSE or CASE-WHEN logic in SQL. ykqzbb bdri etspw fpn mbbf gzmc vmey qmquyev rtewll vigwk