main.py

# Basic Calculator

def calculator():
    print("Select operation:")
    print("1. Add\n2. Subtract\n3. Multiply\n4. Divide")
    choice = input("Enter choice (1/2/3/4): ")

    if choice in ['1', '2', '3', '4']:
        num1 = float(input("Enter first number: "))
        num2 = float(input("Enter second number: "))

        if choice == '1':
            print(f"Result: {num1 + num2}")
        elif choice == '2':
            print(f"Result: {num1 - num2}")
        elif choice == '3':
            print(f"Result: {num1 * num2}")
        elif choice == '4':
            if num2 != 0:
                print(f"Result: {num1 / num2}")
            else:
                print("Division by zero is not allowed.")
    else:
        print("Invalid choice.")

calculator()