Programming · Grade 7 · Chapter 3

Python Setup & Basic Syntax

Taking your first steps into professional text-based coding.

Chapter Goals

What We Will Master Today

Environment: Understand how Python reads and runs text code.
The print() Function: Output text and numbers to the console screen.
Code Comments: Document code cleanly using the `#` symbol.
Debugging Syntax Errors: Spot and fix quotes, parens, and case typos.

The Transition

From Blocks to Real Text Code

In Scratch, a missing block just wouldn't snap. In Python, a missing quote mark stops the entire program! Why switch to text code?

Discuss before revealing: Why do real software developers write text code instead of snapping drag-and-drop blocks?

Core Concept 1

How Python Executes Your Code

Python is an interpreted language. The Python Interpreter reads your script line-by-line from top to bottom.

Source Code (.py)

The text file you write in an editor (VS Code, Replit, IDLE).

Console Output

The output window where results and error messages appear.

Developer Workflow

The 4-Step Coding Cycle

1

Write Text Code

2

Run Interpreter

3

Read Error Message

4

Fix Bug & Re-run

Remember: Errors are not failures — they are instructions telling you where to look!

Core Concept 2

The `print()` Function

print() displays text or values onto the console screen.

print("Hello, World!")
print("Welcome to Grade 7 Computer Science!")

Function name must be lowercase: print
Arguments must be inside parentheses: ()
Text strings must be inside quotes: "" or ''

Code Sandbox

Writing Multiple `print()` Lines

print("Line 1: Loading game...")
print("Line 2: Player connected!")
print("Line 3: Ready to start.")

Rule: Python runs these lines in exact order from top to bottom!

Core Concept 3

Code Comments (`#`)

Comments are notes written for humans. The Python interpreter completely ignores any line starting with #.

# Author: Alex Smith
# Date: September 2026
# Purpose: Display welcome message

print("Game Initialized") # Inline comment explaining this line

Best Practices

Good Comments vs Bad Comments

✓ Helpful Comment

# Calculate final price with 10% discount

total = price * 0.90

✗ Useless Comment

# Set x to 5

x = 5

Debugging

The 3 Types of Bugs in Python

SyntaxError

Grammar rule broken (missing quote, unclosed paren).

NameError

Using a variable or function name that isn't defined.

LogicError

Code runs without crashing, but gives wrong result!

Spot the Mistake 1

Can You Spot the Missing Quote?

# Broken line:
print("Hello, Python world!)

# Error reported by Python:
SyntaxError: unterminated string literal

Fix: Make sure every opening quote " has a matching closing quote "!

Spot the Mistake 2

Python is Case Sensitive!

# Broken line:
Print("Welcome to class!")

# Error reported by Python:
NameError: name 'Print' is not defined. Did you mean 'print'?

Python treats print, Print, and PRINT as completely different names!

Smartboard Voting

Which Line of Code Will Run Without Error?

A) print "Hello World"

B) Print("Hello World")

C) print('Hello World')

D) print("Hello World'

Execution Flow

Top-to-Bottom Execution Flow

print("Step A")
print("Step B")
print("Step C")

The console window will ALWAYS print Step A, then Step B, then Step C. Never out of order!

Core Concept 5

Printing Expressions vs Printing Text

Text String (Inside Quotes)

print("5 + 3")

Console Prints: 5 + 3

Math Expression (No Quotes)

print(5 + 3)

Console Prints: 8

Think-Pair-Share

Why Did Python Print 8 vs "5 + 3"?

Quotes tell Python: "Treat this as literal letters/symbols, do not evaluate it as math!"
No quotes tell Python: "Calculate the value of this math expression first, then print the result!"

Quick Check · Quiz 1

Which character is used to create a single-line comment in Python?

A//

B#

C

D%

Click to reveal answer

Quick Check · Quiz 2

What error occurs if you call `Print("Hi")` instead of `print("Hi")`?

ASyntaxError

BNameError

CTypeError

DLogicError

Click to reveal answer

Quick Check · Quiz 3

What will `print("10" + "20")` display on the screen?

A30

B1020

CError

D"30"

Click to reveal answer

Quick Check · Quiz 4

What happens to comments when Python runs your script?

AThey are printed in green text

BThey are converted to HTML

CThey are completely ignored by the interpreter

DThey cause a SyntaxError

Click to reveal answer

Guided Practice

Fix All Bugs in This Python Script!

# Fix these 3 lines:
Print("Starting program...)
print(Hello world)
#print "Done!"

Goal: Rewrite all 3 lines correctly so the console outputs clean text!

Creative Challenge

ASCII Art with `print()`

print(" /\\_/\\")
print(" ( o.o )")
print(" > ^ <")

Try drawing a robot or rocket ship using only print() statements!

Summary & Takeaways

What We Learned in Chapter 3

Python is interpreted top-to-bottom line by line.
print() sends output to the console; quotes mark literal string text.
Use # to write clear comments for humans to read.
Watch out for SyntaxErrors (missing quotes/parens) and NameErrors (capitalization).

Python Setup & Basic Syntax

What We Will Master Today

From Blocks to Real Text Code

How Python Executes Your Code

Source Code (.py)

Console Output

The 4-Step Coding Cycle

The print() Function

Writing Multiple print() Lines

Code Comments (#)

Good Comments vs Bad Comments

✓ Helpful Comment

✗ Useless Comment

The 3 Types of Bugs in Python

Can You Spot the Missing Quote?

Python is Case Sensitive!

Which Line of Code Will Run Without Error?

Top-to-Bottom Execution Flow

Printing Expressions vs Printing Text

Text String (Inside Quotes)

Math Expression (No Quotes)

Why Did Python Print 8 vs "5 + 3"?

Which character is used to create a single-line comment in Python?

What error occurs if you call Print("Hi") instead of print("Hi")?

What will print("10" + "20") display on the screen?

What happens to comments when Python runs your script?

Fix All Bugs in This Python Script!

ASCII Art with print()

What We Learned in Chapter 3

Create Your 3-Line Python Bio

The `print()` Function

Writing Multiple `print()` Lines

Code Comments (`#`)

What error occurs if you call `Print("Hi")` instead of `print("Hi")`?

What will `print("10" + "20")` display on the screen?

ASCII Art with `print()`