The + operator creates a new list in python when 2 lists are combined using it, the original object is not modified. On the other hand, using methods like extend and append, we add the lists in place, ie, the original object is modified. Also using append inserts the list as a object while + just concatenates the 2 lists.
example
list1 = [1, 2, 3] list2 = ['a', 'b'] list3 = list1 + list2 print(list3)
Output
This will give the output −
[1, 2, 3, 'a', 'b']
When using append −
Example
list1 = [1, 2, 3] list2 = ['a', 'b'] list1.append(list2) print(list1)
Output
This will give the output −
[1, 2, 3, ['a', 'b']]