Write a program of "simple calculator" in python language

 # Program make a simple calculator

# This function adds two numbers

def add(x, y):

    return x + y

# This function subtracts two numbers

def subtract(x, y):

    return x - y

# This function multiplies two numbers

def multiply(x, y):

    return x * y

# This function divides two numbers

def divide(x, y):

    return x / y

print("Select operation.")

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(num1, "+", num2, "=", add(num1, num2))

        elif choice == '2':

            print(num1, "-", num2, "=", subtract(num1, num2))

        elif choice == '3':

            print(num1, "*", num2, "=", multiply(num1, num2))

        elif choice == '4':

            print(num1, "/", num2, "=", divide(num1, num2))

        break

    else:

        print("Invalid Input")