কন্ডিশনাল (Conditionals)

temperature = 35

if temperature >= 30:
    print("It's hot! Get some ice cream 🍦")
    print("Don't forget sunscreen!")
elif temperature >= 20:
    print("Nice weather for a walk")
elif temperature >= 10:
    print("Better grab a jacket")
else:
    print("Stay inside, it's freezing!")

# Only ONE branch runs — the first one that's True
print("\n--- Grade Calculator ---")
score = 87

if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
elif score >= 70:
    grade = "C"
else:
    grade = "F"

print(f"Score {score} → Grade {grade}")

It's hot! Get some ice cream 🍦
Don't forget sunscreen!

--- Grade Calculator ---
Score 87 → Grade B

# Using truthiness to check for empty values
username = ""
if username:
    print(f"Welcome, {username}!")
else:
    print("Please enter a username")

# Checking a list
inventory = ["sword", "shield"]
if inventory:
    print(f"You have {len(inventory)} items")
else:
    print("Your inventory is empty")

# Ternary expression (one-liner if/else)
age = 15
status = "adult" if age >= 18 else "minor"
print(f"Age {age}: {status}")

# Ternary in an f-string
coins = 0
print(f"You have {coins} coin{'s' if coins != 1 else ''}")

Please enter a username
You have 2 items
Age 15: minor
You have 0 coins

# Amusement park ride checker
age = 12
height = 140  # cm
has_parent = True

# Nested approach (works but gets messy)
if age >= 10:
    if height >= 130:
        print("You can ride! 🎢")
    else:
        print("Sorry, too short for this ride")
else:
    print("Sorry, too young for this ride")

# Cleaner with 'and' / 'or'
can_ride_alone = age >= 10 and height >= 130
can_ride_with_parent = age >= 6 and has_parent

if can_ride_alone:
    print("Hop on!")
elif can_ride_with_parent:
    print("You can ride with a parent")
else:
    print("Maybe next year!")

You can ride! 🎢
Hop on!