Day 7/100: Booleans and Logical Operators in Python

This content originally appeared on DEV Community and was authored by Rahul Gupta

Welcome to Day 7 of the 100 Days of Python series!
Today, we’re diving into one of the core foundations of decision-making in programming: Booleans and Logical Operators. These help your code think for itself — to make choices, evaluate conditions, and respond accordingly.

Let’s understand how Python makes decisions under the hood.

What You’ll Learn

• What Booleans are
• How Python evaluates conditions
• Logical operators: and, or, not
• How to combine conditions
• Real-world examples

What Is a Boolean?

A Boolean is a data type that has only two possible values:

True
False

These are case-sensitive (true and false will raise an error).

You can assign them to variables:

is_sunny = True
is_raining = False

Conditions That Return Booleans

Python evaluates expressions and returns either True or False.

x = 5
print(x > 3)    # True
print(x == 10)  # False
print(x != 7)   # True

Common Comparison Operators:

Logical Operators

Logical operators allow you to combine multiple conditions.

1⃣ and – All conditions must be True

age = 20
is_student = True

print(age > 18 and is_student)  # True

2⃣ or – At least one condition must be True

print(age > 18 or is_student == False)  # True

3⃣ not – Reverses the boolean value

print(not is_student)  # False

Real-World Example

Let’s say we’re checking if someone can get a discount:

age = 16
has_coupon = True

if age < 18 or has_coupon:
    print("You get a discount!")
else:
    print("Sorry, no discount.")

Output:

You get a discount!

Bonus: Booleans with Strings and Numbers

Python treats some values as False, like:

• Empty strings: ""
• Zero: 0, 0.0
• Empty lists, dicts, sets: [], {}, set()
• None

Everything else is considered True.

print(bool(""))      # False
print(bool("Hi"))    # True
print(bool(0))       # False
print(bool(42))      # True
print(bool([]))      # False

This becomes useful in conditions:

name = ""

if not name:
    print("Please enter your name.")

Recap

Today you learned:

• The Boolean values True and False
• Comparison operators: ==, !=, >, <, >=, <=
• Logical operators: and, or, not
• How to evaluate and combine conditions
• Real-world usage in if-statements

This content originally appeared on DEV Community and was authored by Rahul Gupta