How to sort NumPy array by column

You can sort the NumPy array by column with the following code. I highly recommend you the “Python Crash Course Book” to learn Python. In this article, you’ll see two examples with solutions.

Example 1: Sort NumPy array by column in Ascending order

# Import the NumPy library as np
import numpy as np

# Create a 1D NumPy array
arr = np.array([[5, 10, 15, 20, 5],
               [13, 4, 25, 16, 7],
               [10, 5, 3, 2, 5]])

# Sort array by 3rd column
output = arr[arr[:, 2].argsort()]

# Display the output
print(output)

Output: Sorted array by 3rd Column

[[10  5  3  2  5]
 [ 5 10 15 20  5]
 [13  4 25 16  7]]

Example 2: Sort in Descending order

# Import the NumPy library as np
import numpy as np

# Create a 1D NumPy array
arr = np.array([[5, 10, 15, 20, 5],
               [13, 4, 25, 16, 7],
               [10, 5, 3, 2, 5]])

# Sort array by 3rd column
output = arr[arr[:, 2].argsort()[::-1]]

# Display the output
print(output)

Output: Sorted array by 3rd Column

[[13  4 25 16  7]
 [ 5 10 15 20  5]
 [10  5  3  2  5]]

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