Logical Operators

Combine conditions with and, or, not

Logical Operators — Combining Conditions

What Is It?

Sometimes one condition isn't enough. You need to check multiple things at once: "Is the user logged in AND an admin?" or "Is it the weekend OR a holiday?" Logical operators let you combine conditions into powerful expressions.

Syntax

python

age = 25
has_id = True

if age >= 18 and has_id:
    print("You can enter!")

Operator	What it does	True Example
`and`	Both sides must be True	`5 > 3 and 2 < 4` → True
`or`	At least one side must be True	`5 > 3 or 2 > 4` → True
`not`	Flips True to False, False to True	`not (5 > 3)` → False

How It Works

`and` — Both must be True

python

age = 20
has_license = True

if age >= 16 and has_license:
    print("You can drive!")  # ✅ Runs: both conditions True

Condition 1	Condition 2	Result
True	True	✅ True
True	False	❌ False
False	True	❌ False
False	False	❌ False

`or` — At least one must be True

python

is_weekend = True
is_holiday = False
if is_weekend or is_holiday:
    print("Sleep in!")  # ✅ Runs: weekend is True

Condition 1	Condition 2	Result
True	True	✅ True
True	False	✅ True
False	True	✅ True
False	False	❌ False

`not` — Invert the result

python

logged_in = False
if not logged_in:
    print("Please log in.")  # ✅ Runs: not False = True

Why Use Logical Operators?

Real-world decisions almost always combine conditions:

**Access control**: `if is_admin or (is_owner and has_permission):`

**Form validation**: `if len(password) >= 8 and has_number and has_uppercase:`

**Shopping cart**: `if item_in_stock and (budget >= price or has_coupon):`

**Game logic**: `if health > 0 and not is_invincible:`

**Search filters**: `if keyword and (category or price_range):`

Common Mistakes

❌ Wrong	Why	✅ Right
`if age >= 18 and <= 65`	Must repeat the variable on both sides	`if age >= 18 and age <= 65:`
`if age == 18 or 19`	`19` is always Truthy — bug!	`if age == 18 or age == 19:`
`if not age >= 18`	Works but reads awkwardly	`if age < 18:` (simpler!)
`if is_weekend == True`	Redundant	`if is_weekend:`

Your Turn!

Write a program that checks if someone can ride a roller coaster. They must:

Be at least 12 years old (`age >= 12`)

Be at least 48 inches tall (`height >= 48`)

Not be afraid of heights (`not afraid`)

Create the variables and write the if statement with and/not.

💡Need a hint? (3 available)

#1Use 'and' when ALL conditions must be true

#2Use 'or' when ANY condition must be true

#3Use 'not' to flip a boolean

🔑Show solution (try it yourself first!)

age = 14
height = 52
afraid = False

if age >= 12 and height >= 48 and not afraid:
    print("Enjoy the ride!")

✏️ Code Editor

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📤 Output

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