Skip to main content

Your First Python Program: Hello World and Print

Building on Lesson 2: In the last lesson, you installed Python and verified it works using python -c "print('Hello, Python!')". That was a one-line program run directly from the terminal. Now you'll learn to create Python files that you can save, edit, and run repeatedly.

This lesson teaches you the most fundamental Python operation: displaying text to the screen using print(). This is how programs communicate with users—and it's the first skill you need before learning anything more complex.

What Is a Python Program File?​

In Lesson 2, you ran Python code directly in the terminal:

python -c "print('Hello, Python!')"

That works for quick tests, but real programs are saved in files with the .py extension. These files:

  • Store your code so you can edit it later
  • Can be run repeatedly without retyping
  • Can be shared with others
  • Can grow from 1 line to thousands of lines

A Python file is just a text file with a .py extension containing Python instructions. The Python interpreter reads the file and executes each instruction in order.

Creating Your First Python File​

Step 1: Create a new file called hello.py

Using any text editor (VS Code, Cursor, Notepad, TextEdit, etc.), create a new file and save it as hello.py.

Step 2: Write your first program

Type this into hello.py:

print("Hello, World!")

Save the file.

Step 3: Run your program

Open your terminal, navigate to the folder where you saved hello.py, and run:

python hello.py

You should see:

Hello, World!

🎉 Congratulations! You just wrote and ran your first Python program from a file.

Understanding print()​

The print() function is how Python displays text to the screen (technically, to "standard output" which is your terminal).

Basic syntax:

print("Your message here")
  • print: The function name
  • (): Parentheses tell Python you're calling a function
  • "Your message here": The text to display (inside quotes)

Why quotes? The quotes tell Python "this is text, not code." Without quotes, Python thinks you're referencing a variable or keyword.

Multiple print() Statements​

You can call print() as many times as you want. Each call displays a new line.

Example (multiple_prints.py):

print("Welcome to Python!")
print("This is line 2")
print("This is line 3")

Output:

Welcome to Python!
This is line 2
This is line 3

Each print() adds a newline automatically. That's why they appear on separate lines.

Adding Comments to Your Code​

Comments are notes you write in your code that Python ignores. They're for humans to read, not for the computer to execute.

Use # to start a comment:

# This is a comment - Python ignores this line
print("Hello, World!")  # You can also add comments after code

Why use comments?

  • Explain why you wrote code a certain way
  • Add reminders for yourself
  • Help others (or your future self) understand your thinking

Example:

# Display a greeting to the user
print("Hello, World!")

# Show multiple lines of output
print("Python is readable")
print("Python is powerful")

Best practice: Comment the why, not the obvious what. Don't write # Print hello before print("Hello"). That's obvious. Write # Greet the user before collecting their input to explain the purpose.

Formatted Output with f-strings (Show-Then-Explain)​

Python has a powerful feature called f-strings (formatted string literals) that let you embed expressions inside strings.

Show first:

print(f"Python version: 3.14")
print(f"Status: Ready")
print(f"Next chapter: Data Types")

Output:

Python version: 3.14
Status: Ready
Next chapter: Data Types

What's happening:

  • The f before the opening quote makes it an f-string
  • F-strings let you format text dynamically
  • In Chapter 14, you'll use f-strings with variables to display changing data

For now, just know that f"..." is how Python formats strings. You'll use this extensively when you learn variables in the next chapter.

Combining Strings with + (Concatenation)​

You can join strings together using +:

print("Hello" + " " + "World")

Output:

Hello World

Notice we added " " (a space) between the words. Without it:

print("Hello" + "World")  # Output: HelloWorld

Concatenation means "joining strings together." You'll use this when building messages from multiple pieces of text.

Try It Yourself: Personal Greeting Program​

Create a file called greeting.py and write:

# Personal greeting program
# This displays information about me

print("=" * 40)  # Print 40 equal signs (a decorative line)
print("About Me")
print("=" * 40)
print()  # Print a blank line
print("Name: [Your Name]")
print("Learning: Python Programming")
print("Tool: Claude Code")
print("Goal: Build AI applications")
print()
print("Next step: Learning data types in Chapter 14")

Run it:

python greeting.py

Expected output:

========================================
About Me
========================================

Name: [Your Name]
Learning: Python Programming
Tool: Claude Code
Goal: Build AI applications

Next step: Learning data types in Chapter 14

What's new here:

  • "=" * 40: Repeats the = character 40 times (string multiplication)
  • print() with no arguments: Prints a blank line
  • Multiple print() statements to build formatted output

Common Mistakes (and How to Fix Them)​

Mistake 1: Forgetting Quotes​

print(Hello)  # ❌ Error: NameError: name 'Hello' is not defined

Fix: Add quotes around text:

print("Hello")  # ✅ Correct

Mistake 2: Mismatched Quotes​

print("Hello')  # ❌ Error: SyntaxError

Fix: Use matching quotes (both " or both '):

print("Hello")  # ✅ Correct
print('Hello')  # ✅ Also correct

Mistake 3: Missing Parentheses​

print "Hello"  # ❌ Error in Python 3 (works in Python 2)

Fix: Always use print() with parentheses:

print("Hello")  # ✅ Correct

Mistake 4: Typo in Function Name​

pint("Hello")  # ❌ Error: NameError: name 'pint' is not defined

Fix: Spell print correctly:

print("Hello")  # ✅ Correct

What You Learned​

By completing this lesson, you now know how to:

✅ Create Python files with the .py extension ✅ Use print() to display text to the screen ✅ Write comments with # to document your code ✅ Run Python programs from the terminal ✅ Use basic f-strings for formatted output ✅ Combine strings with + (concatenation) ✅ Recognize and fix common print() mistakes

Next chapter preview: In Chapter 14 (Data Types), you'll learn to store data in variables using type hints. Instead of hardcoding text in print(), you'll store information and display it dynamically. Variables are where Python gets powerful—and where AI collaboration becomes essential.

Try With AI​

Practice using your AI learning partner (Claude Code or Gemini CLI) to deepen understanding:

Prompt 1: Understand – What Is print() Really Doing? (Bloom's Level 2: Understand)

Ask your AI: "When I run print('Hello'), what actually happens? Where does the
text go? What is 'standard output'? Explain in simple terms with an analogy."

Expected Outcome: You'll understand that print() writes to "standard output" (usually your terminal), and how this relates to other output destinations like files or network sockets.

Prompt 2: Apply – Create Formatted Output (Bloom's Level 3: Apply)

Ask your AI: "Show me 3 ways to print a decorative border around text. Use different
characters (* / = -) and make it look nice. Include the code and explain why each
approach works."

Expected Outcome: You'll see creative uses of print() with string multiplication and learn techniques for formatting terminal output.

Prompt 3: Analyze – Comments vs. Code Clarity (Bloom's Level 4: Analyze)

Show your AI this code:

print("Hello")  # Print hello
print("World")  # Print world

Ask: "Are these comments useful? Why or why not? Show me an example of
GOOD comments for this code. Explain the difference between commenting
the 'what' vs. the 'why'."

Expected Outcome: You'll learn professional commenting practices—when to comment, what to comment, and how to make comments valuable (not redundant).

Prompt 4: Create – Build a Story Program (Bloom's Level 6: Create)

Ask your AI: "Help me create a Python program that tells a short story (3-5 lines)
using print(). The story should have:
- A character introduction
- An action or event
- A conclusion or moral
Show the code and explain how to make it visually appealing with spacing and formatting."

Expected Outcome: You'll practice creative use of print() and learn how to structure program output for readability. This reinforces the fundamental skill before adding complexity in Chapter 14.

You've completed Chapter 13! You now understand what Python is, have it installed, and can write basic programs using print(). In Chapter 14: Data Types, you'll learn to store and manipulate data using variables with type hints—the foundation for all Python programming.