img = plt.imread()
    height = len(img)
    width = len(img[0])
    for row in range(400,460):
        for column in range(300,400):
            img[row][column] = [255,255,255] 

Here is what the above code is Doing:
1. It’s reading in the image.
2. It’s getting the height and width of the image.
3. It’s looping through the rows and columns of the image.
4. It’s changing the color of the pixels in the image.