Module 8: Handling Choices with elif

🤔 Beyond Just Two Options

Sometimes, a simple "if this, then that, otherwise this other thing" isn't enough. What if you have multiple possibilities to check?

Imagine grading an exam: Is it an A? Or maybe a B? Or a C? Or something else? We need a way to check several conditions one after another.

Python's `elif` (short for "else if") lets us build these multi-step decision paths cleanly.

🏗️ The `if / elif / else` Structure

Python checks conditions sequentially until one is TRUE.

Check `if` condition

FALSE

Check `elif` condition

FALSE

(More `elif` checks...)

ALL FALSE

Execute `else` block

Execute `if` block & STOP

Execute `elif` block & STOP

                        score = 85
                        grade = ""
                        # Check conditions one by one
                        
                        if score >= 90:
                            grade = "A"
                        elif score >= 80: # This one is TRUE!
                            grade = "B"         # Code inside runs
                        elif score >= 70: # Skipped
                            grade = "C"
                        else:             # Also skipped
                            grade = "D"
                        
                        print(f"The grade is: {grade}") # Output: B
                    

Key points: Use : after conditions and indent the code blocks underneath. Only one block (the first one whose condition is `True`) will run!

🤖 Thinking in Branches

`if/elif/else` is how we create complex decision paths in algorithms.

Complex Branching

Algorithms often need to handle many different scenarios. The `if/elif/else` structure allows your program to branch its execution based on a series of checks.

Think of it like a decision tree. The computer follows a path, checking each condition (`if`, `elif`s) until it finds a true one or reaches the default (`else`). This lets you build sophisticated logic for AI tasks like classification or rule-based systems.

🧠 Quick Check!

Module 8 Theory Complete!

Excellent work navigating multiple conditions with `elif`! You're building more complex decision-making skills.
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