DataFrames Deep Dive #8: Reshaping (Long, Wide, and the Right Tool) (Pandas + PySpark)

Day 8 of a 10-day deep dive on DataFrames in Pandas and PySpark. Today: melt and pivot in Pandas, pivot in PySpark with its mandatory aggregation, and when SQL is simply the better answer than fighting the DataFrame API. — THE FULL SERIES — #1 What a DataFrame Actually Is #2 Inspecting Data Without Assumptions #3 Selecting Columns Without Losing Your Mind #4 Filtering Rows (And Why Your Filter Might Be Lying) #5 Adding Columns Without Wrecking Performance #6 Aggregations and the Grain Question #7 Joins (Where Real Pipelines Go to Die) #8 Reshaping (Long, Wide, and the Right Tool) (you are here) #9 Reading and Writing (CSV is Not Your Friend) #10 The Skills That Outlast the Library Playlist:    • DataFrames Deep Dive #1: What a DataFrame ...   — ABOUT — Breakfast with Data is a daily one-hour data education program. Python, SQL, Databricks, data governance, and the reasoning skills that make practitioners genuinely good at their work. Hosted by Ola.