B. Making Lists

← A. What Is a List? ⏱️ 5 min C. Adding with append() →

🎯 Learning Goals

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

○ Be able to create an empty list
○ Be able to create a list with items
○ Understand basic list syntax

Core Concepts

Creating a list

Lists Square brackets [] to create one, and items are comma separated by it.

📦 Analogy: packing a box

You can prepare an empty box first and put things in later, or you can receive a box that already has things in it from the start!

# Empty list
my_list = []

# A list with items
numbers = [1, 2, 3]
names = ["Cheolsu", "Younghee", "Minsu"]

List syntax

Form	Code	Description
Empty list	`[]`	Add items later
Number list	`[1, 2, 3]`	Store numbers
String list	`["a", "b"]`	Store text

Things you can put in a list

numbers = [1, 2, 3, 4, 5]           # Numbers
names = ["Cheolsu", "Younghee", "Minsu"]      # Strings
bullets = []                         # Entity objects (added later)

Example Code

from ursina import *

app = Ursina()

# Create an empty list
bullets = []
enemies = []

# A list with items
colors = [color.red, color.blue, color.green]

# Use a color list
for i, c in enumerate(colors):
    Entity(model='cube', color=c, position=(i*2, 0, 0))

app.run()

What Happens

Red, blue, and green cubes appear in a row!

Quiz

Quiz: Empty list

What is the correct way to create an empty list?

Show Answer

Answer: A) my_list = []

[] = list (square brackets)
() = tuple (parentheses)
{} = dictionary (curly braces)

List creation practice:

Empty list: my_list =
Number list: numbers = [1, , 3]
A string to wrap it

🔧 Debug Clinic

Problem: `TypeError: 'tuple' object...`

❌ Wrong Code

my_list = ()  # Parentheses = tuple!
my_list.append("item")  # Error occurs!

Cause: Parentheses () used (becomes a tuple)

✅ Correct Code

my_list = []  # Square brackets = list!
my_list.append("item")  # Works correctly!

Fix: Square brackets [] Use it!

Try Coding It Yourself

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

Creating an empty list

Create an empty list and add items later.

Example Answer

my_list = []
print(f'List: {my_list}')
print(f'Count: {len(my_list)}')

Result: An empty list [] and a count of 0 are printed!

Creating a number list

Create a list containing numbers!

🧩 Key Takeaways

What you learned in this lesson:

Concept	Description
Empty list	`[]` to create
Item list	`[1, 2, 3]` Form
Separator	Comma (`,`) to separate items
Square brackets	`[]` used (not parentheses)

Review Checklist

[ ] Do you know how to create an empty list?
[ ] Do you understand the difference between square brackets and parentheses?
[ ] Do you know that you can put different kinds of data in a list?