02. Conditionals

8/28/26About 12 minAbout 1831 words

02. Conditionals

Conditionals

Exercise 1 — Even or odd

Ask the user to enter an integer. Print whether the number is even or odd.

Example:

Enter a number: 17
17 is odd

Exercise 2 — Password check

Create a variable containing a password.

Ask the user to enter a password. If it is correct, print:

Access granted

Otherwise print:

Access denied

Exercise 3 — Temperature warning

Ask the user for a temperature in degrees Celsius.

Below 0 → print Freezing
From 0 to 20 → print Cold
From 21 to 30 → print Comfortable
Above 30 → print Hot

Use if, elif and else.

Print the temperature using an f-string.

Exercise 4 — Age category

Ask the user for their age.

Print:

under 12 → Child
12–17 → Teenager
18–64 → Adult
65 or older → Senior

Then print a second message containing the age and category, for example:

Age: 23 - Category: Adult

Exercise 5 — Simple calculator

Ask the user for two numbers and an operator (+, -, * or /).

Calculate and print the result.

For example:

First number: 12
Second number: 4
Operator: /
12 / 4 = 3.0

If the user enters an operator that isn't supported, print:

Unknown operator

Exercise 6 — Ternary operator

Ask the user for their age.

Use a ternary operator to create a variable called status:

18 or older → "adult"
otherwise → "minor"

Then print:

You are an adult.

You are a minor.

Exercise 7 — Shopping discount

Ask the user for the price of a product.

If the price is:

less than €50 → no discount
€50 or more → 10% discount

Calculate the final price and print something like:

Original price: €80.00
Discount: 10%
Final price: €72.00

Use a ternary operator to determine the discount percentage.

Exercise 8 — Exam result

Ask the user for a student's score as a percentage.

Print:

below 50 → Failed
50–59 → Passed
60–69 → Good
70–79 → Very good
80–100 → Excellent

Then print the result together with the score.

For example:

Score: 73%
Result: Very good

Assume the user enters a valid score between 0 and 100.

Exercise 9 — Train ticket

Ask the user for:

their name
their age
whether they want a first-class ticket (1 or 2)

The basic ticket price is €20.

Calculate the price:

under 12 years → €10
12–64 years → €20
65 or older → €15

A first-class ticket costs €10 extra.

Print a small ticket:

====================
Train ticket
Passenger: Alice
Age: 67
Class: 1
Price: €25
====================

Use input(), casts, if/elif/else, variables and f-strings.

Create variables containing:

username = "admin"
password = "python123"

Ask the user for their username and password.

The program should:

Check whether the username is correct.
If it is correct, check whether the password is correct.
Print an appropriate message:
- both correct → Welcome, admin!
- username correct but password wrong → Incorrect password
- username wrong → Unknown user

Afterwards, use a ternary operator to create a variable called message containing either "Login successful" or "Login failed", and print it.

Important: Do this without using and, or, or not. The nested if is intentional here.

Not, and, or

Exercise 1 — Weekend

Ask the user to enter a day of the week.

Print:

"It's the weekend!" if the day is "Saturday" or "Sunday".
"It's a weekday." otherwise.

Make sure the comparison is done with ==.

Exercise 2 — Access to a game

Ask the user for their age and whether they have a parental permission ("yes" or "no").

A user can play the game if they are 18 or older, or if they have parental permission.

Print either:

You can play the game.

or:

You cannot play the game.

Use or.

Exercise 3 — School discount

A shop gives a student discount if the customer:

is younger than 26 and
is a student.

Ask for the age and whether the person is a student ("yes" or "no").

Print the price after a 20% discount if they qualify.

For example:

Age: 21
Student: yes
Price: 50
Discount: 20%
Final price: 40.0

Create these variables:

correct_username = "admin"
correct_password = "python123"

Ask the user for a username and password.

The login is successful only if both are correct.

Use and and ==.

Print:

Login successful

or:

Login failed

Exercise 5 — NOT allowed

Ask the user whether they are "allowed" to enter a room.

If the answer is not "yes", print:

You are not allowed to enter.

Otherwise print:

Welcome!

Use not explicitly in the condition.

Exercise 6 — Free shipping

Ask the user for:

the total price of their order
whether they are a member ("yes" or "no")

Free shipping applies if:

the order is €50 or more or
the customer is a member.

Print the shipping cost:

Shipping: €0

or:

Shipping: €5

Then print the total including shipping.

Exercise 7 — Understanding order of operations

Ask the user for three numbers: a, b and c.

Calculate:

result = a + b * c

Print the result.

Then calculate:

result = (a + b) * c

Print that result too.

For example:

a: 2
b: 3
c: 4

Without parentheses: 14
With parentheses: 20

Question: Why are the two results different?

Exercise 8 — Valid temperature

Ask the user for a temperature.

A temperature is considered normal when it is between 18 and 25 degrees, inclusive.

Use a condition containing both and and comparisons.

Print:

Normal temperature

or:

Temperature is outside the normal range

Then use a ternary operator to create a variable called message containing "OK" or "Check temperature" and print it.

Exercise 9 — Cinema ticket

Ask the user for:

their age
whether they have a student card ("yes" or "no")
whether it is Tuesday ("yes" or "no")

The normal ticket price is €12.

The customer gets a €4 discount if they are:

younger than 18 or
a student.

On Tuesdays, everyone gets another €2 discount.

Calculate and print the final price.

For example:

Age: 20
Student: yes
Tuesday: yes

Original price: €12
Discount: €6
Final price: €6

Important: Think carefully about how you combine and and or.

Exercise 10 — Can I go outside?

Ask the user:

Is it raining? (yes/no)
Is it cold? (yes/no)
Do you have an umbrella? (yes/no)

The person can go outside if:

it is not raining, or
it is raining but they have an umbrella.

However, if it is cold, they should print:

Take a jacket!

otherwise:

No jacket needed.

Finally, use a ternary operator to print either:

Have fun outside!

or:

Better stay inside.

More exercises

Exercise 1 — Student results

Write a program that asks for:

student's name
age
score for programming
score for networking
score for databases
number of missed classes

Calculate the average score.

The student passes if:

the average is at least 50 and
none of the individual scores is below 40.

Print the student's name, the three scores and the average.

Then print a result:

average ≥ 80 → Excellent
average ≥ 70 → Very good
average ≥ 60 → Good
average ≥ 50 → Passed
otherwise → Failed

If the student has more than 10 missed classes, also print:

Warning: many classes missed

Finally, use a ternary operator to print whether the student is "Ready for the next year" or "Needs to improve".

Exercise 2 — Computer purchase

A computer shop asks a customer for:

customer name
age
budget
amount of RAM wanted in GB
amount of storage wanted in GB
whether they want a laptop (yes/no)
whether they are a student (yes/no)

Calculate a computer price using these rules:

Base price: €500

16 GB RAM → +€100
more than 16 GB RAM → +€200
512 GB storage → +€50
more than 512 GB → +€150
laptop → +€200

Students receive a €100 discount if the computer costs at least €700.

Then determine whether the customer can afford it.

Print something like:

==============================
Computer purchase
Customer: Alice
RAM: 16 GB
Storage: 1000 GB
Laptop: yes
Student: yes
------------------------------
Price: €850
Discount: €100
Final price: €750
Budget: €800
Can afford: yes
==============================

If the customer cannot afford it, print an appropriate message.

Exercise 3 — Hotel booking

Create a program that asks for:

guest name
age
number of nights
number of adults
number of children
room type (single, double, family)
whether the guest is a member (yes/no)

Use these prices:

single room → €60 per night
double room → €90 per night
family room → €130 per night

Children cost €15 per night each.

Calculate the total price.

Apply these rules:

members get 10% discount
stays of 7 nights or more get another 10% discount
guests younger than 18 cannot book a room themselves

Print the complete booking information and final price.

If the room type is invalid, print:

Unknown room type

If the guest is under 18, print:

You must be at least 18 to make a booking.

Otherwise, calculate the price.

Challenge: Make sure the discounts are calculated in the correct order.

Exercise 4 — Simple bank account

Write a program that simulates a very small bank account.

Start with:

balance = 1000

Ask the user for:

name
age
amount they want to deposit
amount they want to withdraw
whether they have a debit card (yes/no)

Perform the deposit first.

Then process the withdrawal.

A withdrawal is allowed only if:

the amount is not greater than the balance
the amount is greater than 0
the customer is at least 18

If the customer tries to withdraw more money than available:

Insufficient funds

If they are under 18:

Withdrawal not allowed

If the withdrawal is successful, subtract it from the balance.

Finally, print:

====================
Bank account
Name: Alice
Deposit: €200
Withdrawal: €350
Balance: €850
Debit card: yes
====================

If the final balance is below €100, print:

Warning: low balance

Use and, or, not, ==, casts, if, elif, else, and at least one ternary operator.

Exercise 5 — University admission

Write a program that determines whether a student can enter a particular study program.

Ask for:

student's name
age
mathematics score
programming score
networking score
English score
number of failed courses
whether they already have a diploma (yes/no)

Calculate the average score.

The student gets one of these results:

Excellent candidate

If:

average ≥ 75
mathematics ≥ 60
programming ≥ 60
failed courses == 0

Good candidate

If:

average ≥ 60
mathematics ≥ 50
programming ≥ 50
failed courses ≤ 1

Possible candidate

If:

average ≥ 50
programming ≥ 50
they have a diploma

Not admitted

Otherwise.

There is one additional rule:

If the student is younger than 18, they cannot be admitted regardless of their scores.

Print a report such as:

================================
University admission
Name: Thomas
Age: 19

Mathematics: 72
Programming: 81
Networking: 68
English: 75

Average: 74.0
Failed courses: 0
Diploma: yes

Result: Good candidate
================================

Finally, use a ternary operator to print:

Application accepted

Application rejected

based on the admission result.