"""
ndarray indexing
"""

import numpy as np

# given this
arr = np.array([[-1, 2, 0, 4],
                [4, -0.5, 6, 0],
                [2.6, 0, 7, 8],
                [3, -7, 4, 2.0]])

# grab first two rows of arr
a = None

# grab second and third row of arr
b = None

# grab first two rows of arr and first two columns
c = None

# grab elements at indices (0, 3), (1, 2), (2, 1), (3, 0)
d = None

# grab elements > 0
e = None
