Week 6 – Loops: Repeating the Story

Hello Future Coders!

Welcome to Week 6 of our Python Adventures! This week, we’re going to explore loops—the magic tool that lets us repeat actions without writing the same code over and over. Loops help our programs do things like repeat a chorus in your favorite song or a dance move at a party!

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Objective

• Learn what for loops and while loops are and why we use them.

• Understand how loops can help you repeat parts of your story.

• Practice writing loops with interactive fill-in-the-blank challenges and debugging exercises.

• Complete extra challenges to strengthen your understanding of loops.

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1. What Are Loops?

Explanation:

A loop is a way to tell your computer to repeat a block of code many times. Instead of writing the same command over and over, you write it once and let the loop do the work.

Analogy:

Imagine you’re dancing to your favorite song. You repeat the same move every time the chorus comes on. That repeating move is like a loop!

• For Loops:

  Use these when you know exactly how many times to repeat something.

• While Loops:

  Use these when you want to keep repeating until something changes.

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2. Using For Loops

Example:

for i in range(5):
    print("The adventure continues!")

• This for loop repeats the message 5 times.

• Interactive Challenge:

  Fill in the blank to make the loop print "Step X: Onward!" 4 times:

    for i in range(__):
        print("Step", i+1, ": Onward!")
  

  (Hint: The blank should be replaced with the number 4.)

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3. Using While Loops

Example:

counter = 1
while counter <= 5:
    print("Step", counter, ": Keep moving!")
    counter = counter + 1

• This while loop continues until counter becomes 6.

• Interactive Debug Challenge:

  Look at this code and fix the bug:

    count = 1
    while count < 5:
        print("Count is", count)
        count = count  # What should we do here?
  

  (Hint: We need to update count by adding 1 each time.)

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4. Extended Interactive Challenges

Challenge 1: The Summing Loop

Write a program that asks the user for a number and then uses a for loop to calculate the sum of all numbers from 1 up to that number.

Skeleton Code (Fill-in-the-Blanks):

# Ask the user for a number
n = int(input("Enter a number: "))

total = 0
for i in range(1, _______):
    total = total + i
print("The sum from 1 to", n, "is", total)

(Hint: Fill in the blank with the appropriate end value using the variable n.)

Challenge 2: Pattern Printing

Write a program that uses a while loop to print numbers 1 through 5 on separate lines.

Skeleton Code:

number = 1
while number <= 5:
    print(number)
    ___________  # What should we do here?

(Hint: Increase the value of number by 1 each time.)

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5. Additional Homework / Practice

Task 1: Adventure Game Enhancement

Enhance your existing adventure game (from a previous week) by adding a loop. For example, after a decision is made, use a for loop to repeat a suspenseful message:

for i in range(3):
    print("The mysteries of the forest continue to unfold...")

Try changing the number of repetitions and see how it changes the tension in your story!

Task 2: Create Your Own Looping Song

Write a program that prints out the lines of a song or chant repeatedly. For instance:

for i in range(4):
    print("We are the Python coders, hear us code!")

Then, modify it to use a while loop instead.

Task 3: Debug Challenge

Below is a piece of buggy code. Find and fix the error so that it prints numbers 1 to 5:

number = 1
while number < 5:
    print(number)

(Hint: The code never updates number!)

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6. Quiz Time!

1. What is the main purpose of a loop?

   • A) To repeat a set of instructions multiple times.

   • B) To make decisions.

   • C) To print messages on the screen.

2. How many times will this loop run?

    for i in range(5):
        print("Coding is fun!")
   

   • A) 4 times.

   • B) 5 times.

   • C) 6 times.

3. In a while loop, what must you include to prevent an endless loop?

   • A) A print statement.

   • B) An update to the condition (like incrementing a counter).

   • C) A comment explaining the loop.

4. Fill in the blank:

   To print numbers 1 to 5 using a while loop, we update the counter with:

    number = number _______ 1
   

   • A) +

   • B) -

   • C) *

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7. Recap & Reflection

Key Takeaways:

• Loops are a tool that let you repeat tasks without writing them multiple times.

• For loops repeat actions a set number of times, while while loops repeat until a condition changes.

• By using loops, you can create patterns, build interactive stories, and even enhance your games!

Discussion Prompt:

Imagine you’re choreographing a dance for your robot. How many times do you want it to repeat its favorite move? Write your idea down!

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What's Next?

Next week, we’ll learn about Functions (writing simple, reusable code), which will help your programs make decisions, like a smart robot choosing what to do next based on different conditions. Get ready to add even more interactivity to your coding adventures!

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Happy Coding, Future Coders!

Keep practicing these loops, experiment with the challenges, and have fun on your quest for the magic treasure of coding!

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