What is the difference between append() and extend() method in Python?

In the append() method the argument is added as a single element to the end. So, the length of the list increases by one.

Syntax

List.apend(object) 

Example

A = [1, 2]; 
B = [3, 4] 
A.append(B) 

Output: [1, 2, [3, 4]]

In the extend() method, each element in the object is iterated and added to the list.

Syntax

List.extend(object) 

Example

A = [1, 2]; 
B = [3, 4] 
A.extend(B) 

Output: [1, 2, 3, 4]