Calculator .py

def add(x, y):
    return x + y


def subtract(x, y):
    return x - y


def multiply(x, y):
    return x * y


def divide(x, y):
    if y != 0:
       return x / y

    return "Divide by zero"


print("Select operation.")
print("1.Add       +")
print("2.Subtract  -")
print("3.Multiply  *")
print("4.Divide    /")

while True:

    choice = input("Enter choice  1(+)   2(-)   3(*)  4(/) ")

    
    if choice in ('1', '2', '3', '4'):
        try:
            num1 = float(input("Enter first number: "))
            num2 = float(input("Enter second number: "))
        except ValueError:
            print("Invalid input. Please enter a number.")
            continue

        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))
            if num2 == 0:
                    print("Error: Division by zero is not allowed.")
                    continue
                
       
        next_calculation = input("Let's do next calculation? (yes/no): ")
        if next_calculation == "no":
          break
    else:
        print("Invalid Input")