Python Understanding Code Blocks with Indentation

This guide explains Understanding Code Blocks with Indentation through a focused example and practical reasoning. No prior knowledge of this specific operation is required.

Understanding the Concept

Indentation groups statements into blocks under if, else, loops, functions and classes. The customary indentation width is four spaces; the precise block structure changes which lines execute.

When You Would Use This

A checkout script displays a warning only if an order is expensive.

Step-by-Step Example

order_total = 125
if order_total > 100:
    print("Manager approval required")
    print("Review the order")
print("Checkout complete")

How the Example Works

Both indented messages are conditional. The last line is aligned with if, so it runs regardless of the condition.

Example Output

Manager approval required
Review the order
Checkout complete

Try It Yourself

Change the total to 60 and predict exactly which lines are printed.

Common Beginner Mistakes

• Accidentally dedenting a statement that should be conditional.
• Mixing tabs and spaces in the same block.
• Expecting braces to define a Python block.

Key Takeaways

• Indentation groups statements into blocks under if, else, loops, functions and classes.
• Both indented messages are conditional.
• Avoid this mistake: Accidentally dedenting a statement that should be conditional.