Datasets often contain repeated entries. These duplicates, where the same information appears multiple times, can skew analysis and affect model performance. This chapter provides methods for handling duplicate data.

You will learn how to:

• Define what makes a record a duplicate in different scenarios.
• Locate entries that match entirely or only across specific key columns.
• Understand the reasons for removing duplicates.
• Use standard tools to remove these redundant records efficiently.

We will apply these techniques in a practical exercise using sample data.