import numpy as np
arr = np.array([[-1, 2, 0, 4],
[4, -0.5, 6, 0],
[2.6, 0, 7, 8],
[3, -7, 4, 2.0]])
# Printing a range of Array
# with the use of slicing method
arr2 = arr[:2, ::2]
print ("first 2 rows and alternate columns(0 and 2):\n", arr2)
# Printing elements at
# specific Indices
arr3 = arr[[1, 1, 0, 3],
[3, 2, 1, 0]]
print ("\nElements at indices (1, 3), "
"(1, 2), (0, 1), (3, 0):\n", arr3)