PY-L1-09 · True or False? Booleans & Comparisons

Learning Goals

3 min

By the end of this lesson you can:

Recognise True and False as Python's Boolean values.
Predict the result of comparisons between numbers and between strings.
Store a Boolean in a variable and use it inside an if statement.

Warm-Up

5 min

Last lesson we used comparisons like age >= 13 inside if statements. We never paused to ask: what is the result of that comparison? Today, the answer takes centre stage.

Quick predict-the-output puzzle. What does each line print?

print(7 > 3)
print(5 == 5)
print("rice" == "Rice")
print(10 != 10)

Show the answers

True — 7 really is greater than 3.
True — both sides are 5.
False — Python tells n and N apart.
False — 10 is equal to 10, so "not equal" is false.

Today's tool

Every comparison answers with one of two special values: True or False. These are called Booleans, named after George Boole — the 19th-century mathematician who invented this kind of "yes/no logic".

New Concept · The Yes / No Type

12 min

Part 1 · True and False are values, just like 7 or "hello"

We already know about a few types of value:

int — whole numbers like 12.
float — decimal numbers like 3.14.
str — text like "pizza".

Today we add one more: bool, with exactly two values — True and False. Mind the capital letters; true with a small t is just a name Python doesn't know.

is_open    = True
is_closed  = False
print(is_open)
print(is_closed)

Part 2 · Every comparison returns a Boolean

The six comparison operators from last lesson don't just sit inside if. Each one produces a Boolean value that you can print, store, or pass around.

print(8 >= 8)
print(2 < 1)

answer = (5 + 5 == 10)
print(answer)

The line answer = (5 + 5 == 10) first computes the comparison (which is True), then stores that Boolean inside a variable called answer.

Part 3 · Storing a comparison in a variable

This is a really useful trick. Once you save a comparison in a Boolean variable, you can give it a name that reads almost like English.

age   = 12
is_teen = age >= 13
print(is_teen)

if is_teen:
    print("Welcome to the teens.")

Notice we wrote if is_teen:, not if is_teen == True:. Both work — but the shorter version reads better, because is_teen is already a Boolean.

Part 4 · Comparing strings

== and != work on text as well as numbers. Two strings are equal only if every character matches — Python is fussy about capital letters and even spaces.

print("apple" == "apple")
print("apple" == "Apple")
print("apple" == "apple ")
print("apple" != "orange")

Watch out

The "string with a sneaky space" bug is the most common reason a user's typed answer "doesn't match". When you compare input() against a fixed string, double-check there's no extra space inside your quotes.

Part 5 · Chained comparisons — a Python superpower

Many languages make you write age >= 13 AND age <= 19 to check "between 13 and 19". Python lets you write it the way you'd say it out loud:

age = 15
is_teen = 13 <= age <= 19
print(is_teen)

Read 13 <= age <= 19 as: "is 13 less than or equal to age, and age less than or equal to 19?". Both checks must be true for the whole chain to be True.

Worked Example · A Quiz Result Card

12 min

Teacher Ivy wants a tiny program that turns a quiz score into a friendly result card. We'll compute three Boolean variables first, then print them, then react to them. Save this as result_card.py.

Code

# result_card.py — turn a score into Boolean results

name  = input("Student name? ")
score = int(input("Score out of 100? "))

# 1. Compute Booleans from comparisons
passed      = score >= 50
excellent   = score >= 80
full_marks  = score == 100

# 2. Print the raw Booleans, just to see them
print()
print(name, "scored", score)
print("Passed?     ", passed)
print("Excellent?  ", excellent)
print("Full marks? ", full_marks)

# 3. React using the Booleans
print()
if full_marks:
    print("🏅 Perfect score — luar biasa!")
elif excellent:
    print("Amazing work.")
elif passed:
    print("Nice — you cleared the pass mark.")
else:
    print("Keep practising — you'll get there.")

Two sample runs (lines you type are bold):

Output · top of the class

Student name? <strong>Mia</strong>
Score out of 100? <strong>92</strong>

Mia scored 92
Passed?      True
Excellent?   True
Full marks?  False

Amazing work.

Output · not quite there

Student name? <strong>Hugo</strong>
Score out of 100? <strong>38</strong>

Hugo scored 38
Passed?      False
Excellent?   False
Full marks?  False

Keep practising — you'll get there.

What changed from PY-L1-08?

Last lesson the comparison lived inside the if: if score >= 50:. Today we lifted the comparison out and gave it a name: passed = score >= 50. The if reads almost like English now — if passed:. Same logic, much friendlier code.

Basic

5 min

Type each task into your editor and run it with two or three different inputs.

01 Print the Booleans

Save the result of each comparison in a variable and print it. The first one is done for you — finish the rest:

a = 10 > 5
print(a)

b = ???
print(b)

c = ???
print(c)

Hint

Any false comparison works for b — try 1 == 2 or "yes" == "no". Any true one works for c.

Challenge 1

4 min

02 Are you the admin?

Ask the user for a username with input(). Save is_admin = (name == "admin") in a Boolean. Then use if is_admin: to print one of two messages — a "Welcome boss!" line if true, otherwise a normal greeting.

Hint

Three lines of code:

name     = input("Username? ")
is_admin = (name == "admin")
if is_admin:
    print("Welcome, boss!")
else:
    print("Hello,", name)

Remember — the comparison is case-sensitive. "Admin" is not the same as "admin".

Challenge 2

4 min

03 In range with a chained comparison

Ask the user for a temperature in °C, convert it with int(), and check whether it lands in the "pleasant" band 22 to 28 using a chained comparison. Print the Boolean, then a message.

Hint

Build the chain as is_pleasant = 22 <= temp <= 28. Then if is_pleasant: prints "Lovely weather for a walk."; otherwise print "Best stay indoors.".

Challenge 3 · Library Card Validator

8 min

Reed Sri Library in Leeds needs a tiny check-in helper. Build it.

Your file must:

Ask for the visitor's name.
Ask for their age and convert with int().
Ask "Do you have your library card? (yes/no)" and save the answer in a string variable card_answer.
Compute these Booleans:
- has_card — is card_answer exactly equal to "yes"?
- is_member_age — is the age between 7 and 80 (inclusive) using a chained comparison?
- is_kid — is the age less than 13?
Print all three Booleans on their own lines, prefixed by their names.
Use if has_card: to print one of two final messages: "✅ You may enter, {name}." or "✗ Sorry, {name} — please bring your card next time.".

Stretch goal. Add one more line — when is_kid is True, also print "🍭 Pick up a free sticker on your way in!" right after the entry message.

Show one possible solution

# library_validator.py — sweet little gate-keeper

# 1. Ask
name        = input("What's your name? ")
age         = int(input("How old are you? "))
card_answer = input("Do you have your library card? (yes/no) ")

# 2. Booleans
has_card       = card_answer == "yes"
is_member_age  = 7 <= age <= 80
is_kid         = age < 13

# 3. Show the Booleans
print()
print("has_card:      ", has_card)
print("is_member_age: ", is_member_age)
print("is_kid:        ", is_kid)

# 4. Use one Boolean to decide
print()
if has_card:
    print("✅ You may enter,", name + ".")
else:
    print("✗ Sorry,", name, "— please bring your card next time.")

# 5. Stretch — extra welcome for kids
if is_kid:
    print("🍭 Pick up a free sticker on your way in!")

If the user types Yes with a capital Y, your check returns False — that's the case-sensitivity bug from Part 4. We'll learn how to handle that politely in PY-L1-10.

Recap

3 min

Every comparison in Python returns a Boolean — either True or False. We can store these results in variables, give them readable names, and use them inside if statements to keep code clear. Python's chained comparison (13 <= age <= 19) is a friendly shortcut for "in this range".

Vocabulary Card

Boolean (bool): A type with only two values: True and False. Capital first letter.
comparison: A line like a == b or x < y whose result is a Boolean.
Boolean variable: A variable that holds True or False. Often named with words like is_, has_, can_.
chained comparison: A Python shortcut: a <= b <= c means "b is between a and c".

Extra Mission

4 min

Create a new file called birthday_card.py — a tiny birthday-greeting maker.

Rules:

Ask for the user's name and age (convert with int()).
Set these three Boolean variables, each from a single comparison:
- is_kid — true if the age is below 13.
- is_teen — true if the age is between 13 and 19 (inclusive). Use a chained comparison.
- is_adult — true if the age is 20 or above.
Print all three Booleans on their own lines, each prefixed by a label.
Use if / elif / else on the Boolean variables (not on the raw age) to print one tailored birthday message.

Bring birthday_card.py to next lesson — we'll wish each other happy birthday with each other's scripts!

Sample · birthday_card.py

# birthday_card.py — a small birthday greeting maker

# 1. Ask
name = input("What is your name? ")
age  = int(input("How old will you be? "))

# 2. Three Booleans, each one comparison
is_kid   = age < 13
is_teen  = 13 <= age <= 19
is_adult = age >= 20

# 3. Show them
print()
print("is_kid:   ", is_kid)
print("is_teen:  ", is_teen)
print("is_adult: ", is_adult)

# 4. Pick a tailored greeting
print()
if is_kid:
    print("🎈 Happy birthday,", name + "! Enjoy a slice of cake lapis.")
elif is_teen:
    print("🎉 Happy birthday,", name + "! Big teen energy.")
else:
    print("🎂 Wishing you a wonderful birthday,", name + ".")

Your messages and emojis can differ — what matters is that you compute three Booleans first, then branch on those Booleans (not on age directly).

# result_card.py — turn a score into Boolean results name = input("Student name? ") score = int(input("Score out of 100? ")) # 1. Compute Booleans from comparisons passed = score >= 50 excellent = score >= 80 full_marks = score == 100 # 2. Print the raw Booleans, just to see them print() print(name, "scored", score) print("Passed? ", passed) print("Excellent? ", excellent) print("Full marks? ", full_marks) # 3. React using the Booleans print() if full_marks: print("🏅 Perfect score — luar biasa!") elif excellent: print("Amazing work.") elif passed: print("Nice — you cleared the pass mark.") else: print("Keep practising — you'll get there.")

# library_validator.py — sweet little gate-keeper # 1. Ask name = input("What's your name? ") age = int(input("How old are you? ")) card_answer = input("Do you have your library card? (yes/no) ") # 2. Booleans has_card = card_answer == "yes" is_member_age = 7 <= age <= 80 is_kid = age < 13 # 3. Show the Booleans print() print("has_card: ", has_card) print("is_member_age: ", is_member_age) print("is_kid: ", is_kid) # 4. Use one Boolean to decide print() if has_card: print("✅ You may enter,", name + ".") else: print("✗ Sorry,", name, "— please bring your card next time.") # 5. Stretch — extra welcome for kids if is_kid: print("🍭 Pick up a free sticker on your way in!")

True or False? — Booleans & Comparisons

Learning Goals

Warm-Up

New Concept · The Yes / No Type

Part 1 · True and False are values, just like 7 or "hello"

Part 2 · Every comparison returns a Boolean

Part 3 · Storing a comparison in a variable

Part 4 · Comparing strings

Part 5 · Chained comparisons — a Python superpower

Worked Example · A Quiz Result Card

What changed from PY-L1-08?

Basic

Challenge 1

Challenge 2

Challenge 3 · Library Card Validator

Recap

Vocabulary Card

Extra Mission

Sample · birthday_card.py

True or False? — Booleans & Comparisons

Learning Goals

Warm-Up

New Concept · The Yes / No Type

Part 1 · True and False are values, just like 7 or "hello"

Part 2 · Every comparison returns a Boolean

Part 3 · Storing a comparison in a variable

Part 4 · Comparing strings

Part 5 · Chained comparisons — a Python superpower

Worked Example · A Quiz Result Card

What changed from PY-L1-08?

Basic

Challenge 1

Challenge 2

Challenge 3 · Library Card Validator

Recap

Vocabulary Card

Extra Mission

Sample · birthday_card.py