arr1 = [1, 2, 3]
arr2 = arr1.copy() # or arr2 = arr1[:]
arr1[0] = 5 # this only changes value on arr1 NOT arr2
print(f"arr1 = {arr1}") # [5, 2, 3]
print(f"arr2 = {arr2}") # [1, 2, 3]arr1 = [[1, 2], [3, 4]]
arr2 = arr1.copy() # or arr2 = arr1[:]
arr1[0][0] = 5 # this changes value on both arr1 and arr2
print(f"arr1 = {arr1}") # [[5, 2], [3, 4]]
print(f"arr2 = {arr2}") # [[5, 2], [3, 4]]So to copy a 2D Array or Matrix we need to traverse the matrix and create new memory location for new Matrix e.g.
arr1 = [[1, 2], [3, 4]]
arr2 = [[c for c in r] for r in arr1]