Python Loops - Exercises

:books: What you'll learn

• How to use for loops to iterate through lists
• How to implement while loops with conditions
• Using else statements with loops
• Controlling loop flow with break and continue
• Creating interactive programs with user input and loops

:computer: Getting Started

:information_source: Time Required Total activity time: 45-60 minutes

• Exercise Set 1: 25-30 minutes
• Exercise Set 2: 20-30 minutes

1. Click the link here
2. Make a copy of the Colab Notebook into your Google Drive
3. Follow the exercises below and write your code in the notebook

:computer: Exercise Set 1: Loop Fundamentals

Time estimate: 25-30 minutes

Write the program using loops to show the outcome for each question.

Question One: Basic Loops ⏱️ 5-7 minutes

For and While loop comparison

1. Using for loop:

   • Use the provided list one_to_ten
   • Print each number on a new line

2. Using while loop:

   • Initialize a counter variable
   • Print numbers 1 to 10
   • Remember to increment your counter!

:bulb: :bulb: Hint: For the while loop, don't forget to:

• Start your counter at 1
• Use the condition counter <= 10
• Increment the counter inside the loop

Expected output:

1
2
3
4
5
6
7
8
9
10

Question 2: Else with Loops ⏱️ 5-7 minutes

Using else statement with loops

1. For loop with else:
   • Iterate through the list multiply5
   • Print each item
   • Use else to print "That's all for the items in the list" after the loop completes

Expected output:

5
10
15
20
That's all for the items in the list

2. While loop with else:
   • Start with 7
   • Print multiples of 7 up to and including 70
   • Use else to print "That's all multiples of 7 up to 70" when done

:bulb: :bulb: Remember: The else block executes when the loop completes normally (not interrupted by break)

Expected output:

text

7
14
21
28
35
42
49
56
63
70
That's all multiples of 7 up to 70

Question 3: Break Statement ⏱️ 5-7 minutes

Controlling loop execution with break

1. For loop with break:
   • Use range(11, 21) to generate numbers 11 to 20
   • Print each number
   • Use break when the number equals 15
2. While loop with break:
   • Start with counter at 11
   • Print numbers but stop when reaching 15
   • Use break to exit the loop tip :bulb: Note: The break statement should be inside an if condition checking if the current number is 15

Expected output:

11
12
13
14
15

Question 4: Continue Statement ⏱️ 5-7 minutes

Skipping iterations with continue

1. For loop with continue:

   • Use range(11, 21) for numbers 11 to 20
   • Skip printing when the number is 15
   • Use continue to skip to the next iteration

2. While loop with continue:

   • Count from 11 to 20
   • Skip the number 15 using continue
   • Remember to increment before continuing!

:bulb: :warning: Common mistake: In the while loop, make sure to increment your counter BEFORE the continue statement, or you'll create an infinite loop!

Expected output:

text

11
12
13
14
16
17
18
19
20

:art: Exercise Set 2: Real-World Application

Time estimate: 20-30 minutes

Question One: Camping Bag Program ⏱️ 20-30 minutes

Scenario: Your school is organizing camping in the forest. You need to pack important items in your backpack (water bottle, flashlight, first aid kit, etc.).

Task: Create an interactive program to manage your camping bag items.

:memo: Step-by-step instructions:

1. Initialize your bag:

   python

   bag = []  # Create an empty list
   

2. Get the number of items:

   python

   ask = int(input("How many items you want to put inside your bag? "))
   

3. Create the while loop:

   • Set condition: while ask > 0:
   • Inside the loop:
     1. Ask for item name: item = input("Enter item name: ")
     2. Add to bag: bag.append(item)
     3. Decrease counter: ask = ask - 1

4. Display the final bag:

   python

   print("Items in your bag:", bag)
   

tip :bulb: Enhancement ideas:

• Add a check to prevent duplicate items
• Display how many items are left to add
• Show the bag contents after each addition

Expected output:

:emoji: Submission Instructions

:warning: Important! Before submitting:

1. :white_check_mark: Test all your code in the Colab notebook
2. :white_check_mark: Verify each output matches the expected results
3. :white_check_mark: Save your notebook to your Google Drive
4. :white_check_mark: Make sure all exercises are completed

:information_source: :link: Submit your exercise here Your submission helps track your learning progress!

:wrench: Troubleshooting

Common issues:

1. Infinite loops: Make sure you're updating your counter variable in while loops
2. Off-by-one errors: Check your range() parameters and loop conditions
3. IndentationError: Python is sensitive to indentation - use consistent spacing
4. TypeError with input(): Remember to convert input to int() when needed

:bulb: Need help? If you're stuck:

1. Review the lesson material on loops
2. Check your indentation carefully
3. Use print statements to debug your code
4. Ask your instructor or classmates for guidance