# calculator.py

class Calculator: def __init__(self): self.history = []

    def add(self, num1, num2):
        """Add two numbers"""
        result = num1 + num2
        self.history.append(f"{num1} + {num2} = {result}")
        return result

    def subtract(self, num1, num2):
        """Subtract two numbers"""
        result = num1 - num2
        self.history.append(f"{num1} - {num2} = {result}")
        return result

    def multiply(self, num1, num2):
        """Multiply two numbers"""
        result = num1 * num2
        self.history.append(f"{num1} * {num2} = {result}")
        return result

    def divide(self, num1, num2):
        """Divide two numbers"""
        if num2 == 0:
            raise ValueError("Cannot divide by zero!")
        result = num1 / num2
        self.history.append(f"{num1} / {num2} = {result}")
        return result

    def get_history(self):
        """Get the calculation history"""
        return self.history

def main(): calculator = Calculator()

    while True:
        print("\nOptions:")
        print("1. Add")
        print("2. Subtract")
        print("3. Multiply")
        print("4. Divide")
        print("5. Get History")
        print("6. Quit")

        choice = input("Choose an option: ")

        if choice == "1":
            num1 = float(input("Enter the first number: "))
            num2 = float(input("Enter the second number: "))
            print(f"Result: {calculator.add(num1, num2)}")
        elif choice == "2":
            num1 = float(input("Enter the first number: "))
            num2 = float(input("Enter the second number: "))
            print(f"Result: {calculator.subtract(num1, num2)}")
        elif choice == "3":
            num1 = float(input("Enter the first number: "))
            num2 = float(input("Enter the second number: "))
            print(f"Result: {calculator.multiply(num1, num2)}")
        elif choice == "4":
            num1 = float(input("Enter the first number: "))
            num2 = float(input("Enter the second number: "))
            try:
                print(f"Result: {calculator.divide(num1, num2)}")
            except ValueError as e:
                print(e)
        elif choice == "5":
            print("\nCalculation History:")
            for i, history in enumerate(calculator.get_history()):
                print(f"{i+1}. {history}")
        elif choice == "6":
            break
        else:
            print("Invalid option. Please choose a valid option.")

if __name__ == "__main__": main()