Boolean Values

Booleans are the simplest data type in Python: every expression either evaluates to True or False.

What you’ll learn

• What Boolean values are
• How comparisons and bool() evaluate values
• Common falsy values and practical examples

Tip: Booleans power program flow — if, while, list filtering, and more.

Quick comparison examples

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These comparisons return a Boolean value:

a = 3
b = 5
print(a > b)   # False
print(a < b)   # True
print(a == 3)  # True
print(a != b)  # True

Truthiness and bool()

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Not every value is explicitly True or False; Python uses the concept of “truthiness”:

• Values that are “empty” or zero are considered Falsey
• Non-empty values and non-zero numbers are Truthy

Examples:

print(bool(""))          # False (empty string)
print(bool("Rahhhhhhh")) # True  (non-empty string)
print(bool(0))            # False
print(bool(22))           # True
print(bool([]))           # False (empty list)
print(bool([1, 2]))       # True

Common falsy values

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• None
• False
• 0, 0.0, 0j
• "" (empty string)
• [], (), {} (empty containers)

Using Booleans in if statements

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liam = 20
russell = 30

if russell > liam:
	print("Russell is greater than Liam")
else:
	print("Liam is greater or equal to Russell")

Functions that return Booleans

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You can write functions that return Boolean expressions directly:

def is_even(n):
	return n % 2 == 0

print(is_even(4))  # True
print(is_even(5))  # False

Useful built-ins

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• isinstance(obj, type) — checks the object type
• any(iterable) — True if any element is truthy
• all(iterable) — True only if every element is truthy

print(isinstance(3, int))       # True
print(any([0, "", 5]))         # True (5 is truthy)
print(all([1, 2, 3]))           # True
print(all([1, 0, 3]))           # False (0 is falsy)

A short practical example: filtering a list

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items = [0, 1, "", "hello", None, [], [1]]
truthy = [x for x in items if x]
print(truthy)  # [1, 'hello', [1]]

Final notes

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Booleans are tiny but powerful — mastering truthiness helps you write clearer conditions and cleaner code. Try changing the example values above and re-running them to see how small changes affect outcomes.