Expressions vs Statements

Python code can be divided into two categories: expressions and statements. Understanding the difference helps you understand how Python works.

Expressions

Expressions are code that produces a value. They evaluate to something you can use:

5 + 3              # Expression → produces 8
"hello" + "world"  # Expression → produces "helloworld"

Think of expressions as "questions" that Python answers with a value. When Python sees 5 + 3, it calculates the answer (8) and gives you that value.

Key idea: Expressions have a value. You can use them anywhere you need a value.

note

You'll learn more about expressions when you study operators. For now, just know that expressions produce values.

Statements

Statements are code that does something but doesn't produce a value you can use directly:

print("Hello")  # Statement → prints something (doesn't give you a value back)

Statements:

• Perform actions (like printing, assigning values to variables)
• Don't produce values you can use
• Are the "commands" that make your program do things

Key idea: Statements are "commands" that Python executes. They do work but don't give you a value back.

note

You'll see more examples of statements when you learn about variables and conditionals. For now, just know that statements perform actions.

Why this matters

Understanding expressions vs statements helps you understand:

• Why some code produces values and some doesn't:

  • 5 + 3 is an expression—it produces the value 8
  • print("Hello") is a statement—it does something (prints) but doesn't give you a value

• The difference between doing something and getting a value:

  • Expressions give you something you can use
  • Statements just do work

This distinction will become clearer as you learn more about operators and other Python features. For now, just remember: expressions produce values, statements perform actions.

Summary

Understanding expressions vs statements helps you understand how Python works:

• Expressions produce values—they're like "questions" that Python answers with a value (e.g., 5 + 3 produces 8)
• Statements perform actions—they're "commands" that do work but don't give you a value back (e.g., print("Hello") prints but doesn't return a value)
• Why it matters: This distinction explains why some code produces values you can use, while other code just performs actions

As you learn more about Python, you'll see expressions and statements everywhere. Understanding this difference will help you write better code and avoid common mistakes!