What's the difference between the list methods append() and extend()?

In Python, the append() and extend() methods are both used to modify lists, but they have different purposes and behaviors:

    append():
        The append() method is used to add an element to the end of a list.
        It takes a single argument, which is the element you want to add.
        The original list is modified in place, and the method does not return a new list.

    extend():
        The extend() method is used to add multiple elements to the end of a list.
        It takes an iterable (such as a list, tuple, or string) as an argument and appends each element from the iterable to the list.
        The original list is modified in place, and the method does not return a new list.

Here's an example to illustrate the differences:

python

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

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

In the append() example, the number 4 is added as a single element to the end of the list.

In the extend() example, the iterable [4, 5, 6] is added to the end of the list, so each individual element within the iterable becomes a new element in the list.

Choose between append() and extend() based on whether you want to add a single element or multiple elements to your list. If you're adding a single element, use append(). If you're adding multiple elements from an iterable, use extend().