How to Merge and Sum DataFrames in Python: Two Simple Methods

Introduction

A follower asked how to add corresponding columns from two separate tables using Python. The author explains that the task is more than a simple sum() call because the column names may differ.

Two solution approaches are presented.

Method One

Rename the columns of the second DataFrame to match those of the first, then add them directly.

Method Two

Use NumPy to perform element‑wise addition, then convert the result back into a DataFrame, which can be more convenient when column names differ.

Additional Question

The author also addresses a follow‑up query about setting custom headers for the resulting DataFrame, illustrated with another image.

Conclusion

The article demonstrates two practical techniques for adding corresponding columns of two tables in Python, acknowledging that other methods may also exist and encouraging readers to experiment.