Python truth 4

python_truth4.py

class Coffee:
    def __init__(self, total_amount):
        self.total_amount = total_amount
    
    def drink(self, amount):
        if amount > self.total_amount:
            raise ValueError("Not enough coffee!")
        self.total_amount -= amount
    
    def __bool__(self):
        return bool(self.total_amount)


cup = Coffee(100)
bool(cup)  # True

cup.drink(100)
if not cup:
    print("Panic!")
# Panic!