Python Booleans: True and False Values

What is a Boolean in Python?

A Boolean is a data type that represents one of two possible values: True or False.

Booleans help your code make decisions. You can use them to create programs that do different things based on specific conditions. For example, you can check if a user is logged in before you show them a dashboard.

How Python Creates Boolean Values

You usually get a Boolean value through a comparison. Comparison operators look at two values and return True if the statement is accurate, or False if it isn't. You don't normally type True or False directly - instead, Python evaluates an expression and gives you one of them.

Example: Simple Comparisons

See how Python evaluates these expressions by running the code below.

print(10 > 9)
print(10 == 9)
print(10 < 9)

Your output will appear here...

Primary Comparison Operators

Here is how to use the primary comparison operators in Python to get Booleans:

• == (Equal to): Checks if two values are equal. For example, 10 == 10 returns True.
• != (Not equal to): Checks if two values are not equal. For example, 10 != 5 returns True.
• > (Greater than): Checks if the value on the left is greater than the value on the right. For example, 10 > 5 returns True.
• < (Less than): Checks if the value on the left is less than the value on the right. For example, 5 < 10 returns True.
• >= (Greater than or equal to): Checks if the left value is greater than or equal to the right value. For example, 10 >= 10 returns True.
• <= (Less than or equal to): Checks if the left value is less than or equal to the right value. For example, 5 <= 10 returns True.

Example:

user_age = 25
is_adult = user_age >= 18  
print(is_adult)

account_balance = 50
can_withdraw = account_balance > 100  
print(can_withdraw)

Your output will appear here...

Understanding 'Truthy' and 'Falsy' Values

In Python, some values act like False even though they're not the Boolean value False. We call these "falsy" values. Everything else acts like True, and we call them "truthy."

Falsy Values

Python considers these values as False:

• The special value None
• The Boolean value False
• The number zero: 0 and 0.0
• Empty text: ""
• Empty lists: []
• Empty dictionaries: {}

Truthy Values

Python considers any value that's not on the "falsy" list as True. Here are some examples:

• Non-empty text like "hello"
• Any number except zero, like 1, -10, or 0.5
• Lists with items like [1, 2]
• The Boolean value True

Example: Testing Truthy and Falsy

You can test if a value is truthy or falsy using the bool() function.

print(bool(0))      # False
print(bool(15))     # True
print(bool(""))     # False
print(bool("text")) # True
print(bool([]))     # False
print(bool([1]))    # True

Your output will appear here...

How Functions Return Booleans

You can create functions that return a Boolean value. This approach helps you write clean, reusable code that checks for specific conditions.

def is_of_legal_age(age):
    return age >= 21

can_buy_alcohol = is_of_legal_age(25)

if can_buy_alcohol:
    print("Purchase approved.")
else:
    print("Purchase denied.")

Your output will appear here...

Using Booleans with Logical Operators

Logical operators (and, or, not) let you combine multiple Boolean expressions. You use them when you need to check more than one condition.

1. and Operator

The and operator returns True only when both conditions are True. If either condition is False, the entire expression becomes False.

2. or Operator

The or operator returns True when at least one of the conditions is True. It returns False only when both conditions are False.

3. not Operator

The not operator flips a Boolean value. It turns True into False and False into True.

Example: Logical Operators in Action

# AND
print(22 >= 18 and True)

# OR
print(True or False)

# NOT
print(not False)

Your output will appear here...

Common Mistakes to Avoid

You can write cleaner and more reliable code when you avoid these common mistakes with Booleans:

• Confusing assignment (=) with comparison (==): The single equals sign assigns a value. The double equals sign checks for equality. When you use = instead of == in a comparison, you create bugs.
• Forgetting to capitalize True and False: Python's Boolean keywords are case-sensitive. When you use true or false, Python raises a NameError.

Final Challenge: Discount Eligibility

Apply your logic skills! Write a check to see if a customer gets a discount.

Your Task:

1. A customer is eligible for a discount if they are a student OR if they are a senior (over 60).
2. Use logical operators to calculate the Boolean result.

is_student = False
age = 65

has_discount = is_student or age > 60

print(has_discount)

Your output will appear here...