Grouping and Aggregating Data in Pandas: A Deep Dive into the `sum` Function

Locating Subgroups in a Pandas DataFrame and Replacing Values in the Original DataFrame: A Step-by-Step Guide

Applying Functions per Subgroups with Pandas: A Comprehensive Solution

Resolving the Missing GroupBy Column Issue in Pandas DataFrames

Converting Values to Lists When Grouping Data with Pandas

Grouping and Iterating through DataFrame Groups in Python: An Efficient Approach

Passing Group Key as Argument with Groupby Apply

Calculating Rolling Mean by Year and Client/Business Combinations in Pandas DataFrame

How to Group by Columns A + B and Count Row Values for Column C in a Pandas DataFrame

Merging Rows from Two DataFrames Based on Their Index Value Using Python Pandas