How to get only integer or float input

I am trying to make a calculator in python. However, I want the user to be able to input an integer or float. But not a string, how can I do that?

This is my current code, however, the if statement does not do the intended job.

def calculator():
     x = (input("Please enter a number: "))

     y = (input("Please enter a second number"))

     if x or y != int or float:

          print("Invalid input, please enter a number")
          x = input("Please enter a number: ")
          y = input("Now, please enter a second number: Press enter to leave blank: ")