Python · Lists
Add Elements
The full text of this chapter, to read or revisit. To practise, do the exercises.
▶ Do the exercisesExercise 1 — List Methods Introduction
Lists in Python come with built-in methods that allow you to manipulate them. In this chapter, we'll explore three essential methods for adding elements to lists:
•
append()
- Add a single item to the end of a list
•
insert()
- Insert an item at a specific position
•
extend()
- Add multiple elements from another iterable
These methods are essential when you want to build and grow your lists. Let's use our Codémon examples to see how they work!
Exercise 2 — The append() Method
The
append()
method adds an item to the end of a list. This is one of the most commonly used list methods when you need to grow a list.
# Starting with an empty Codémon team
my_team = []
print("Starting team:", my_team)
# Catching Codémon one by one
my_team.append("Aquachu")
print("After catching Aquachu:", my_team)
my_team.append("Pyrochu")
print("After catching Pyrochu:", my_team)
Notice how
append()
adds the new item to the end of the list. The method modifies the list directly and doesn't return a new list.
Exercise 3 — Using append()
Complete the code to add
"Florachu"
to your Codémon team using the append() method.
my_team = ["Aquachu", "Pyrochu"]
print("Team before:", my_team)
# Add Florachu to the team
my_team.____(____)
print("Team after:", my_team)
Options: append add "Florachu" Florachu insert
Hint : The append() method adds an item to the end of a list. The syntax is list_name.append(item).
Exercise 4 — The insert() Method
The
insert()
method adds an item at a specified position in a list. This is useful when you need to add an item somewhere other than at the end of the list.
The syntax is
list.insert(index, item)
where:
•
index
is the position where you want to insert the item
•
item
is the value you want to add
# A team with some Codémon
my_team = ["Aquachu", "Pyrochu", "Florachu"]
print("Original team:", my_team)
# Insert a new Codémon at the beginning (index 0)
my_team.insert(0, "insert_1")
print("After inserting at beginning:", my_team)
# Insert a new Codémon in the middle (index 2)
my_team.insert(2, "insert_2")
print("After inserting in the middle:", my_team)
If the index is out of range (larger than the length of the list), the item is simply appended to the end of the list (Python doesn't raise an error).
Exercise 5 — Using insert()
Complete the code to insert "Florachu" as the second Codémon in your team (at index 1).
my_team = ["Aquachu", "Pyrochu"]
print("Team before:", my_team)
# Insert Florachu as the second Codémon
my_team.____(____________)
print("Team after:", my_team)
Options: insert append 1 2 , : "Aquachu" "Florachu"
Hint : The insert() method adds an item at a specified position. The syntax is list.insert(index, item). List indices start at 0.
Exercise 6 — The extend() Method
The
extend()
method adds all the elements from another list to the end of the current list.
codemons_1 = ['Aquachu']
codemons_1.extend(['Pyrochu', 'Florachu'])
print("After extend():", codemons_1) # Adds each element individually
Important:
extend()
is different from
append()
!
-
append()
adds its argument as a single item
-
extend()
adds each element of the iterable individually
codemons_1, codemons_2 = ['Aquachu'], ['Aquachu']
codemons_1.append([['Pyrochu', 'Florachu']])
codemons_2.extend(['Pyrochu', 'Florachu'])
print("After append():", codemons_1) # Adds the list as a single item
print("After extend():", codemons_2) # Adds each element individually
Exercise 7 — Understanding extend()
What will be the value of
team
after the following code runs?
team = ['Aquachu', 'Pyrochu']
team.extend(['Florachu'])
Options
• ['Aquachu', 'Pyrochu', 'Florachu']
• ['Aquachu', 'Pyrochu', 'F', 'l', 'o', 'r', 'a', 'c', 'h', 'u']
• ['Aquachu', 'Pyrochu', ['Florachu']]
• ['Aquachu', 'Pyrochu', ('Florachu',)]
Hint : Remember: When you use extend() with a string, each character of the string is added as a separate element to the list.
Exercise 8 — Match Adding Methods
Match each method with its correct description.
Items to match
• y.append(item)
• y.insert(0, item)
• y.extend([a, b])
• y.insert(2, item)
Definitions
• Adds a single item to the end of the list
• Adds an item at the beginning of the list
• Adds multiple elements individually to the list
• Inserts an item at index 2 (third position)
Exercise 9 — Understanding insert() Position
Given this code, what will be the final team?
team = ["Aquachu", "Pyrochu", "Florachu"]
team.insert(1, "Zap")
print(team)
Options
• ["Zap", "Aquachu", "Pyrochu", "Florachu"]
• ["Aquachu", "Zap", "Pyrochu", "Florachu"]
• ["Aquachu", "Pyrochu", "Zap", "Florachu"]
• ["Aquachu", "Pyrochu", "Florachu", "Zap"]
Hint : Remember: ```insert(1, item)``` places the new item at index 1 (second position), pushing existing elements to the right.
Exercise 10 — Building Your Team
Complete the code to build a Codémon team step by step:
1. Add "Pyrochu" to the end
2. Insert "Aquachu" at the beginning
3. Add both "Florachu" and "Rockachu" at once
team = ["Zap"]
print("Starting team:", team)
# Add Pyrochu to the end
team.____("Pyrochu")
print("After append:", team)
# Insert Aquachu at the beginning
team.____(________ "Aquachu")
print("After insert:", team)
# Add Florachu and Rockachu at once
team.____(["Florachu", "Rockachu"])
print("Final team:", team)
Options: append insert extend 0 1 , add
Hint : Use ```append()``` to add one item at the end, ```insert(0, item)``` to add at the beginning, and ```extend()``` to add multiple items from a list.
Exercise 11 — Challenge - Build Your Dream Team
You're building your dream Codémon team from scratch! Start with an empty list and use the three methods you've learned to create the perfect team.
Your tasks:
1. Add "Pyrochu" to your empty team
2. Insert "Aquachu" at the beginning (it will be your leader)
3. Add "Florachu" at the end
4. Add multiple Codémon at once: ["Zap", "Rockachu"]
Your final team should be:
["Aquachu", "Pyrochu", "Florachu", "Zap", "Rockachu"]
Starter code
# Start with an empty team
my_team = []
# Task 1: Add Pyrochu to your empty team
# Task 2: Insert Aquachu at the beginning (index 0)
# Task 3: Add Florachu at the end
# Task 4: Add Zap and Rockachu at once
# Display your final team
print("My dream team:", my_team)