How to Perform Full Outer Index Join in Pandas and Handle NaN Values for Non-Matching Indexes

Merging DataFrames Based on Two Conditions: A Comprehensive Guide

Merging DataFrames with Conditionnal Aggregation Using Dates

Merging Dataframes without Duplicating Columns: A Guide with Left and Outer Joins

Here is a complete code snippet that combines all the interleaved code you wrote in a nice executable codeblock:

Using Dplyr to Merge and Transform Dataframes in R

Understanding Conflict Between MERGE Statements and Foreign Key Constraints When Synchronizing Data Between Databases