How can I use NumPy for conditional filtering in Python?

How can I use NumPy for conditional filtering in Python?

You can use boolean indexing in NumPy to filter arrays based on conditions. For example, if you have an array and want to filter values greater than a certain threshold, you can do it like this:

import numpy as np

arr = np.array([1, 2, 3, 4, 5])
filtered_arr = arr[arr > 3]
print(filtered_arr)  # Output: [4 5]

Can you explain how boolean indexing works?

Sure! Boolean indexing allows you to create a boolean array that represents whether each element meets a certain condition. When you use this boolean array to index the original array, it returns only the elements that satisfy the condition.

What if I want to filter based on multiple conditions?

You can combine conditions using logical operators like & (and) and | (or). For example:

filtered_arr = arr[(arr > 2) & (arr < 5)]
print(filtered_arr)  # Output: [3 4]