Extending Python Lists: Examples with Code for AP CSP

📚 Quick Study Guide

• ➕ List extension involves adding elements to an existing list.
• 🐍 Python provides several ways to extend lists, including: `append()`, `extend()`, `insert()`, and list concatenation (`+`).
• ➡️ `append(element)`: Adds a single element to the end of the list.
• 🔗 `extend(iterable)`: Adds elements from an iterable (like another list, tuple, or string) to the end of the list.
• 📍 `insert(index, element)`: Inserts an element at a specific index in the list.
• 💡 List Concatenation (`+`): Creates a new list by combining two existing lists.
• ⚠️ Be mindful of the differences: `append` adds the element as-is, while `extend` unpacks the iterable and adds each element individually.

🧪 Practice Quiz

1. Which method adds a single element to the end of a Python list?
   1. append()
   2. extend()
   3. insert()
   4. concat()
2. Which method adds multiple elements from an iterable to the end of a Python list?
   1. append()
   2. extend()
   3. insert()
   4. add()
3. What is the output of the following code?

   list1 = [1, 2, 3]
   list1.append([4, 5])
   print(list1)

   1. [1, 2, 3, 4, 5]
   2. [1, 2, 3, [4, 5]]
   3. Error
   4. [4, 5]
4. What is the output of the following code?

   list1 = [1, 2, 3]
   list1.extend([4, 5])
   print(list1)

   1. [1, 2, 3, [4, 5]]
   2. [1, 2, 3, 4, 5]
   3. Error
   4. [4, 5]
5. Which method inserts an element at a specific position in a Python list?
   1. append()
   2. extend()
   3. insert()
   4. add()
6. What is the output of the following code?

   list1 = [1, 2, 3]
   list1.insert(1, 4)
   print(list1)

   1. [1, 2, 3, 4]
   2. [1, 4, 2, 3]
   3. [4, 1, 2, 3]
   4. Error
7. Which operator can be used to concatenate two lists in Python?
   1. *
   2. +
   3. -
   4. /