D. Indentation

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🎯 Learning Goals

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

○ Understand why indentation matters
○ Understand the difference between inside and outside a loop
○ Be able to indent correctly

Core Concepts

What is indentation?

🚪 Analogy: the loop's room

Indentationmeans putting spaces in front of code. In Python, indentation is the loop's roomIt is!

Inside the room vs. outside the room

for i in range(3):
    print(i)      # Inside the room (repeated)
    print(i * 2)  # Inside the room (repeated)

print("Done!")      # Outside the room (runs only once)

Position	Indentation	Run
Inside the room	O	Repeated execution
Outside the room	X	Runs only once

Indentation rules

Usually 4 spaces Or 1 tab Use
Colon (:) Indent from the next line
The same block is the same depthindent it with

Example Code

from ursina import *

app = Ursina()

for i in range(3):
    # Inside the room: repeated
    Entity(model='cube', position=(i*2, 0, 0))
    print(f"Cube {i} created!")

# Outside the room: runs only once
print("All cubes created!")

app.run()

What Happens

After creating 3 cubes, prints "All cubes created!"

Quiz

Quiz: indentation

How should the code inside a loop be written?

Show Answer

Answer: A) It must be indented

In Python, the code inside a loop must be indented. Without indentation, IndentationErroroccurs!

Indentation practice:

Number of indentation spaces: spaces
Indented code runs
Without indentation only this runs

🔧 Debug Clinic

Problem: `IndentationError: expected an indented block`

❌ Wrong Code

for i in range(3):
print(i)  # No indentation!

Cause: indentation is missing

✅ Correct Code

for i in range(3):
    print(i)  # 4-space indentation!

Fix: Add 4 spaces!

Try Coding It Yourself

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

Indentation practice

The code inside a loop needs to be indented!

Example Answer

for i in range(3):
    print(f'Inside the room: {i}')  # Repeated 3 times

print('Outside the room!')  # Runs only once

Result: '방 안' prints 3 times, '방 밖' prints only once!

Indenting multiple lines

Try putting multiple lines inside the loop!

🎯 Fill-in-the-Blank Mission

Fill in the blanks to complete the code!

Check answers

for i in range(3):
    print(f'Repetition {i}')

print('Done!')