How Do You Concatenate Two Lists in Python?

You can concatenate two lists in Python using the addition operator (+). This operator combines the elements of both lists into a new list, preserving the order of elements.

Here's a simple example:

list1 = [1, 2, 3]
list2 = [4, 5, 6]

concatenated_list = list1 + list2

print(concatenated_list)  # Output: [1, 2, 3, 4, 5, 6]

Practical Insights:

• Concatenation creates a new list: The original lists remain unchanged.
• Order matters: The order of elements in the resulting list follows the order of the original lists.
• Data types: Both lists must contain the same data type or compatible data types for concatenation to work.

Alternative Methods:

• extend() method: The extend() method modifies the original list by adding elements from another list to the end.

list1 = [1, 2, 3]
list2 = [4, 5, 6]

list1.extend(list2)

print(list1)  # Output: [1, 2, 3, 4, 5, 6]

• List comprehension: You can use list comprehension to create a new list containing elements from both original lists.

list1 = [1, 2, 3]
list2 = [4, 5, 6]

concatenated_list = [element for sublist in [list1, list2] for element in sublist]

print(concatenated_list)  # Output: [1, 2, 3, 4, 5, 6]

Choosing the Right Method:

• Use the + operator for creating a new list without modifying the original lists.
• Use the extend() method when you want to modify the original list.
• Use list comprehension for a more concise and efficient way to concatenate lists, especially when dealing with nested lists.