pass_by_assignment_demo.py

def list_mutator(inner_list):
    inner_list.append(4)

def list_setter(inner_list):
    inner_list = inner_list + [4]

def list_returner(inner_list):
    inner_list = inner_list + [4]
    return inner_list



outer_list = [1, 2, 3]
print('')
print('list_mutator old:\t' + str(id(outer_list)) + ' | ' + repr(outer_list))
list_mutator(outer_list)
print('list_mutator new:\t' + str(id(outer_list)) + ' | ' + repr(outer_list))

outer_list = [1, 2, 3]
print('')
print('list_setter old:\t' + str(id(outer_list)) + ' | ' + repr(outer_list))
list_setter(outer_list)
print('list_setter new:\t' + str(id(outer_list)) + ' | ' + repr(outer_list))

outer_list = [1, 2, 3]
print('')
print('list_returner old:\t' + str(id(outer_list)) + ' | ' + repr(outer_list))
new_outer_list = list_returner(outer_list)
print('list_returner return val:\t' + str(id(new_outer_list)) + ' | ' + repr(new_outer_list))


# list_mutator old:	2786847806464 | [1, 2, 3]
# list_mutator new:	2786847806464 | [1, 2, 3, 4]

# list_setter old:	2786858164672 | [1, 2, 3]
# list_setter new:	2786858164672 | [1, 2, 3]

# list_returner old:	2786854748608 | [1, 2, 3]
# list_returner return val:	2786858165184 | [1, 2, 3, 4]