How to get the 5th element in the 1st row of a 2D NumPy array? How to get element in 2nd array in NumPy?

To get the 5th element in the 1st row of a 2D NumPy array, you can use square brackets to specify the row index and column index of the element. Remember that in Python, indexing starts at 0. Here's an example:

import numpy as np

arr = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

print(arr[0, 4])  
# output: 
IndexError: index 4 is out of bounds for
 axis 1 with size 3

In this example, we created a 2D NumPy array arr with three rows and three columns. We then tried to access the 5th element in the 1st row of the array using the index arr[0, 4]. However, this will result in an IndexError because the array has only 3 columns, and the index 4 is out of bounds.

If you meant to get the element in the 1st row and 5th column, you can use the index arr[0, 4] instead. Note that this is the 5th element in the 1st row, not the 5th element overall in the array.

import numpy as np

arr = np.array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10], [11, 12, 13, 14, 15]])

print(arr[0, 4])  # output: 5

In this updated example, we created a 2D NumPy array arr with three rows and five columns. We then accessed the 5th element in the 1st row of the array using the index arr[0, 4], which returns the value 5.