midPandas
What is categorical data in Pandas?
Updated May 17, 2026
Short answer
Categorical data represents fixed categories with limited unique values.
Deep explanation
Pandas stores categories internally as integer codes, improving memory efficiency and performance for repeated string-like values.
Real-world example
Storing gender, country, or product categories.
Common mistakes
- Using category for highly unique data like IDs.
Follow-up questions
- Is categorical data ordered?
- Why use categorical dtype?