old_list = [[1, 2, 3], [1,3,1], [1,2,7]]
new_list = list(old_list)
print(old_list is new_list)
old_list[1][2] = 98
new_list[2][1] = 75
print("\nOld list: " + str(old_list))
print("New list: " + str(new_list))

  
>>> lst1 = [[1, 2, 3], [4, 5, 6]]
>>> 
>>> lst2 = [i[:] for i in lst1]
>>> 
>>> lst2[0][0] = 0
>>> lst1
[[1, 2, 3], [4, 5, 6]]
>>> lst2
[[0, 2, 3], [4, 5, 6]]
>>>