When working with lists in Python, it is common to need to append items from one list to another. In this article, we will explore different ways to solve the problem of appending items from a specific list to another list in Python. We will present three different solutions, each with its own advantages and disadvantages.

Solution 1: Using a for loop

x = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
y = [10, 11, 12]

specific_list_index = 1
specific_list = x[specific_list_index]

for item in y:
    specific_list.append(item)

print(x)

In this solution, we use a for loop to iterate over each item in the y list. We then append each item to the specific list in the x list. This solution is straightforward and easy to understand. However, it modifies the original list in place, which may not be desirable in some cases.

Solution 2: Using the extend() method

x = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
y = [10, 11, 12]

specific_list_index = 1
specific_list = x[specific_list_index]

specific_list.extend(y)

print(x)

In this solution, we use the extend() method to add all the elements from the y list to the specific list in the x list. The extend() method modifies the original list in place, similar to the for loop solution. However, it provides a more concise and readable syntax.

Solution 3: Using list concatenation

x = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
y = [10, 11, 12]

specific_list_index = 1
specific_list = x[specific_list_index]

x[specific_list_index] = specific_list + y

print(x)

In this solution, we use list concatenation to create a new list that combines the specific list and the y list. We then assign this new list to the specific list index in the x list. This solution does not modify the original list in place, which can be advantageous in certain scenarios where immutability is desired.

After evaluating these three solutions, the best option depends on the specific requirements of your program. If you need to modify the original list in place, both the for loop and extend() method solutions are suitable. However, if immutability is important or if you want to create a new list, the list concatenation solution is a better choice.