What is fancy indexing in NumPy?

What is fancy indexing in NumPy?

Fancy indexing in NumPy allows you to access and modify array elements using arrays of indices.

Can you give me an example of fancy indexing?

Sure! If you have an array arr = np.array([10, 20, 30, 40, 50]), you can access elements using arr[[1, 3]] to get [20, 40].

What happens if I use a boolean array for indexing?

Using a boolean array will return elements where the boolean array is True. For example, arr[[True, False, True, False, True]] will return [10, 30, 50].

Are there any performance considerations with fancy indexing?

Yes, fancy indexing can be less efficient than regular indexing, especially for large arrays, as it creates copies of the data.