C. Adding Items with append()

← B. Creating a List ⏱️ 5 min D. Removing with remove() →

🎯 Learning Goals

By the end of this lesson, you'll be able to:

○ append() function to add items
○ Be able to add bullets/enemies to a list in a game
○ Understand how to call methods

Core Concepts

What is append()?

append() function adds an item to the end of a list.

📬 Analogy: a mailbox

Just like MailboxLike putting a letter into a mailbox! A new letter is always added at the very back.

fruits = ["Apple", "Banana"]
fruits.append("Orange")
# fruits = ["사과", "바나나", "오렌지"]

Syntax

list name.append(to add Item)

Dot (.) connects it to the list
The item to add goes inside the parentheses

Using it in games

bullets = []

# Add each time a bullet is fired
bullet = Entity(model='cube')
bullets.append(bullet)  # Add to the list!

Example Code

from ursina import *

app = Ursina()

# Empty list
cubes = []

# Add 5 with a loop
for i in range(5):
    cube = Entity(
        model='cube',
        color=color.red,
        position=(i*2, 0, 0)
    )
    cubes.append(cube)  # Add to the list!

print(f"Cube count: {len(cubes)}")  # 5

app.run()

What Happens

Five cubes are stored in the list!

Quiz

Quiz: Adding items

What is the name of the function that adds an item to a list?
Hint: my_list.___("새 항목")

Show Answer

Answer: append

append means "to add." It adds a new item to the end of the list!

my_list.append("new item")

append() practice:

fruits = ["사과", "바나나"] Given a list:

"포도"to the end of fruits: fruits. ("포도") → ["사과", "바나나", "포도"]
With a dot (.) connect the name and the function
The added item is always positioned there

🔧 Debug Clinic

Problem: `AttributeError: 'NoneType' object has no attribute 'append'`

❌ Wrong Code

bullets.append(bullet)  # bullets doesn't exist!

Cause: The list wasn't created

✅ Correct Code

bullets = []  # Create an empty list first
bullets.append(bullet)

Fix: You have to create an empty list first!

Try Coding It Yourself

Take what you learned with the blocks and write it yourself in Python code!

Adding with append()

Add items one by one to an empty list.

Example Answer

fruits = []
fruits.append('Apple')
fruits.append('Banana')
fruits.append('Orange')
print(fruits)

Result: ['사과', '바나나', '오렌지'] is printed!

Adding with a loop

Try using a loop together with append()!

🧩 Key Takeaways

What you learned in this lesson:

Concept	Description
append()	Add an item to the end of a list
Syntax	`list.append(item)`
Position	Always added at the very back
Caution	You have to create the list first

Review Checklist

[ ] append() Can you explain the role of the function?
[ ] Do you know how to connect a list and a function with a dot (.)?
[ ] In a loop, append() can you make use of it?