import numpy as np

a = []

b = 2

c = np.array([1, 2, 3])
a.append(b)
a.append(c)

print(a)
print(b)
print(c)

b = 3
c[0] = 4

print(a)
print(b)
print(c)






$ python test.py
[2, array([1, 2, 3])]
2
[1 2 3]
[2, array([4, 2, 3])]
3
[4 2 3]