Python If Else 🚀

Prerequisites: Python Booleans

Mentor's Note: Conditional logic is the "Brain" of your program. It allows your code to look at a situation and decide: "If this happens, do that!" 💡

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🌟 The Scenario: The Traffic Light 🚦

Imagine you are driving your car towards an intersection.

• The Logic:
  • IF the light is Green 🟢: GO!
  • ELSE IF (Elif) the light is Yellow 🟡: SLOW DOWN!
  • ELSE (If nothing else is true) 🔴: STOP!
• The Result: You navigate the intersection safely based on the current state. ✅

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📖 Concept Explanation

1. The if Statement

The simplest form of decision making. If the condition is True, the code runs.

if score > 35:
    print("You passed! 🎉")

2. The elif (Else If)

Used when you have more than two options to check. You can have as many elif blocks as you need.

3. The else

The "Catch-All". It runs if NONE of the previous conditions were true.

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🎨 Visual Logic: The Decision Flow

graph TD
    A[Start 🏁] --> B{Is it Raining? 🌧️}
    B -- Yes --> C[Take Umbrella ☂️]
    B -- No --> D{Is it Sunny? ☀️}
    D -- Yes --> E[Wear Sunglasses 😎]
    D -- No --> F[Just Walk 🚶]
    C --> G[End 🏁]
    E --> G
    F --> G

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💻 Implementation: Decision Lab

Python (3.10+)

# 🛒 Scenario: Grading a Student
# 🚀 Action: Using if-elif-else ladder

score = 85

if score >= 90:
    grade = "A+ 🏆"
elif score >= 80:
    grade = "A ✨"
elif score >= 70:
    grade = "B 👍"
else:
    grade = "Keep trying! 💪"

print(f"Your result: {grade}")

# 🛍️ Outcome: "Your result: A ✨"

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📊 Sample Dry Run (Ladder)

Input: score = 75

Step	Condition	Result	Action
1	score >= 90	False	Skip to next ⏭️
2	score >= 80	False	Skip to next ⏭️
3	score >= 70	True ✅	Assign "B" and EXIT ladder!

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📈 Technical Analysis

• Indentation: Every line inside an if block MUST be indented.
• Short Hand (Ternary): For simple 1-line checks: result = "Pass" if score > 35 else "Fail"

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🎯 Practice Lab 🧪

Task: The ATM Withdrawal

Task: Write a program where balance = 500. Ask for a withdrawal amount. If withdrawal <= balance, print "Success", else print "Insufficient Funds". Hint: Use if withdrawal <= balance:. 💡

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← Back: Booleans | Next: Loops →

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