Python Basics — Control Flow Practice Exercises

Control Flow Practice Exercises

Test your understanding of if/elif/else, ternary operators, match-case, and truthy/falsy values.

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Exercise 1: BMI Calculator

Write a program that asks for weight (kg) and height (m), calculates BMI, and prints the category.

BMI Range	Category
< 18.5	Underweight
18.5–24.9	Normal weight
25.0–29.9	Overweight
≥ 30	Obese

Expected Output:

Enter weight (kg): 70
Enter height (m): 1.75

BMI: 22.9
Category: Normal weight

Solution

weight = float(input("Enter weight (kg): "))
height = float(input("Enter height (m): "))

bmi = weight / (height ** 2)

if bmi < 18.5:
    category = "Underweight"
elif bmi < 25:
    category = "Normal weight"
elif bmi < 30:
    category = "Overweight"
else:
    category = "Obese"

print(f"\nBMI: {bmi:.1f}")
print(f"Category: {category}")

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Exercise 2: Day Type Checker (match-case)

Use match-case to classify a day as “Weekday”, “Weekend”, or “Invalid”. Handle case-insensitive input.

Expected Output:

Enter a day: Saturday
Weekend!

Enter a day: MONDAY
Weekday

Enter a day: Funday
Invalid day: Funday

Solution

day = input("Enter a day: ").strip().lower()

match day:
    case "monday" | "tuesday" | "wednesday" | "thursday" | "friday":
        print("Weekday")
    case "saturday" | "sunday":
        print("Weekend!")
    case _:
        print(f"Invalid day: {day.title()}")

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Exercise 3: Ticket Pricing

Write a program that calculates ticket price based on age, day, and membership.

Rules:

• Base price: $20
• Children (under 12): 50% off
• Seniors (65+): 40% off
• Weekends: $5 surcharge (after discount)
• Members: extra 10% off (applied last)

Expected Output:

Enter age: 10
Weekend? (yes/no): yes
Member? (yes/no): no

Base price: $20.00
Child discount (50%): -$10.00
Weekend surcharge: +$5.00
Final price: $15.00

Solution

age = int(input("Enter age: "))
is_weekend = input("Weekend? (yes/no): ").strip().lower() == "yes"
is_member = input("Member? (yes/no): ").strip().lower() == "yes"

base = 20.00
price = base
discount_label = ""

print(f"\nBase price: ${base:.2f}")

if age < 12:
    discount = base * 0.50
    price -= discount
    print(f"Child discount (50%): -${discount:.2f}")
elif age >= 65:
    discount = base * 0.40
    price -= discount
    print(f"Senior discount (40%): -${discount:.2f}")

if is_weekend:
    price += 5
    print(f"Weekend surcharge: +$5.00")

if is_member:
    member_discount = price * 0.10
    price -= member_discount
    print(f"Member discount (10%): -${member_discount:.2f}")

print(f"Final price: ${price:.2f}")

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Exercise 4: Truthy/Falsy Quiz

Without running the code, predict the output. Then verify by running it.

print("A:", bool([]))
print("B:", bool([0]))
print("C:", bool(""))
print("D:", bool(" "))
print("E:", bool(0.0))
print("F:", "hello" or "world")
print("G:", "" or "default")
print("H:", "hello" and "world")
print("I:", "" and "world")
print("J:", None or 0 or "" or [] or "found")

Solution

A: False        # Empty list is falsy
B: True         # Non-empty list (even with falsy element)
C: False        # Empty string is falsy
D: True         # String with a space is truthy
E: False        # 0.0 is falsy
F: hello        # or returns first truthy value
G: default      # "" is falsy, so or returns "default"
H: world        # and returns last value when all truthy
I:              # and returns first falsy value ("")
J: found        # or keeps going until it finds a truthy value

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Exercise 5: Rock Paper Scissors

Build a rock-paper-scissors game where the user plays against the computer. Use match-case or if-elif to determine the winner.

Expected Output:

Choose rock, paper, or scissors: rock
Computer chose: scissors

You win! Rock beats scissors.

Solution

import random

choices = ["rock", "paper", "scissors"]

user = input("Choose rock, paper, or scissors: ").strip().lower()
computer = random.choice(choices)

print(f"Computer chose: {computer}\n")

if user not in choices:
    print(f"Invalid choice: {user}")
elif user == computer:
    print("It's a tie!")
else:
    match (user, computer):
        case ("rock", "scissors") | ("paper", "rock") | ("scissors", "paper"):
            print(f"You win! {user.title()} beats {computer}.")
        case _:
            print(f"You lose! {computer.title()} beats {user}.")

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Scoring Guide

Exercises Completed	Level
5/5	Expert — Control flow mastered!
4/5	Advanced — Strong conditional logic
3/5	Intermediate — Good foundation
1-2/5	Beginner — Review the chapter concepts

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Next Chapter: Loops →