juniorPandas
How to merge DataFrames in Pandas?
Updated May 17, 2026
Short answer
Use merge() to combine DataFrames based on keys.
Deep explanation
merge performs SQL-like joins such as inner, outer, left, and right joins based on matching columns or indices.
Real-world example
Combining customer and order datasets.
Common mistakes
- Not specifying join type leading to unexpected results.
Follow-up questions
- Difference between merge and concat?
- What is a left join?