Calculator with simple ui.py

# Program make a simple calculator


class Calculator:
    def __init__(self):
        pass

    def add(self, num1, num2):
        """
        This function adds two numbers.

        Examples:
        >>> add(2, 3)
        5
        >>> add(5, 9)
        14
        >>> add(-1, 2)
        1
        """
        return num1 + num2

    def subtract(self, num1, num2):
        """
        This function subtracts two numbers.

        Examples:
        >>> subtract(5, 3)
        2
        >>> subtract(9, 5)
        4
        >>> subtract(4, 9)
        -5
        """
        return num1 - num2

    def multiply(self, num1, num2):
        """
        This function multiplies two numbers.

        Examples:
        >>> multiply(4, 2)
        8
        >>> multiply(3, 3)
        9
        >>> multiply(9, 9)
        81
        """
        return num1 * num2

    def divide(self, num1, num2):
        """
        This function divides two numbers.

        Examples:
        >>> divide(4, 4)
        1
        >>> divide(6, 3)
        2
        >>> divide(9, 1)
        9
        """
        if num2 == 0:
            print("Cannot divide by zero")
        else:
            return num1 / num2


calculator = Calculator()


print("1.Add")
print("2.Subtract")
print("3.Multiply")
print("4.Divide")

while True:
    # Take input from the user
    choice = input("Enter choice(1/2/3/4): ")

    # Check if choice is one of the four options
    if choice in ("1", "2", "3", "4"):
        num1 = float(input("Enter first number: "))
        num2 = float(input("Enter second number: "))

        if choice == "1":
            print(calculator.add(num1, num2))

        elif choice == "2":
            print(calculator.subtract(num1, num2))

        elif choice == "3":
            print(calculator.multiply(num1, num2))

        elif choice == "4":
            print(calculator.divide(num1, num2))
        break
    else:
        print("Invalid Input")