How to Add Corresponding Columns from Two DataFrames in Python: Two Simple Methods

Preface

A fan in a Python community asked how to add corresponding columns from two separate tables, which initially seemed like a simple sum() operation but turned out to be more complex.

Implementation

Two solutions are offered to address the problem.

Method 1

Rename the columns of the second DataFrame to match those of the first, then add them directly. The process and code are illustrated below.

Method 2

Use NumPy to perform element‑wise addition of the underlying arrays and convert the result back to a DataFrame, which many find easier to understand.

Additional Question

An extra query about setting table headers when column names differ is also addressed.

Conclusion

The article summarizes the two methods for adding matching columns of two tables, thanks the contributors, and encourages readers to try other approaches.