Comparing Values of a Certain Row with a Certain Number of Previous Rows in R's data.table

A Different Merge: Combining Pandas DataFrames with Common Elements

Grouping Last Amount Paid by City and Year: SQL Solutions with Subqueries and CTEs

How to Handle Multiple Data Types in Pandas GroupBy Operations

Subsetting Table in R when IDs are Non-Unique and Values Match

The Issue with dplyr's Group By and Summarise Functions for Handling Duplicate Values When Calculating Aggregates

Handling Empty Sets of Columns when Grouping Data with Pandas: A Comprehensive Guide

Solving Duplicate Data in SQL Case Statements with MAX() Function

Implementing Time Lag in R with dplyr and data.table

Grouping by in R as in SQL: A Deep Dive into Data Manipulation and Joining