midNumPy
What is boolean indexing in NumPy?
Updated May 17, 2026
Short answer
Boolean indexing filters arrays using conditions.
Deep explanation
It creates a boolean mask and selects elements where the condition is True, enabling powerful filtering operations.
Real-world example
Filtering out invalid sensor readings.
Common mistakes
- Confusing boolean indexing with slicing.
Follow-up questions
- Can multiple conditions be used?
- Does it create a copy?