Append vs Extend vs Insert in Python

The Python has append, extend, and insert are methods used to add elements to lists, but they differ in how they add elements and where they add them in the list.

1. append() Method:

• The append() method is used to add a single element to the end of a list.
• It takes one argument, which is the element to be added.
• It modifies the original list in place.

   my_list = [1, 2, 3]
   my_list.append(4)
   print(my_list)  # Output: [1, 2, 3, 4]

2. extend() Method:

• The extend() method is used to add multiple elements (usually another list) to the end of a list.
• It takes an iterable (e.g., a list, tuple, or string) as its argument.
• It unpacks the elements of the iterable and adds them one by one to the end of the original list.
• It also modifies the original list in place.

   my_list = [1, 2, 3]
   my_list.extend([4, 5, 6])
   print(my_list)  # Output: [1, 2, 3, 4, 5, 6]

3. insert() Method:

• The insert() method is used to add an element at a specific index within the list.
• It takes two arguments: the index at which to insert the element and the element itself.
• It modifies the original list in place.

   my_list = [1, 2, 3]
   my_list.insert(1, 4)
   print(my_list)  # Output: [1, 4, 2, 3]

In this example, 4 is inserted at index 1, pushing the existing elements to the right.

Here’s a summary of their differences:

• append() adds a single element to the end.
• extend() adds multiple elements to the end from an iterable.
• insert() adds an element at a specific index.

Choose the method that best suits your specific use case and the desired location for adding elements to the list.