import numpy as np

a = np.arange(4)
# array([0, 1, 2, 3])

b = a
c = a
d = b

a[0] = 11
print(a)
# array([11,  1,  2,  3])

b is a  # True
c is a  # True
d is a  # True

b = a.copy()    # deep copy
print(b)        # array([11, 22, 33,  3])
a[3] = 44
print(a)        # array([11, 22, 33, 44])
print(b)        # array([11, 22, 33,  3])