def newton(): #No parameter needed if the user is going to supply one


    # Can intiialize tolerance outside of the loop since its value never changes
    tolerance = 0.000001

#Give user square root for every number they enter.
    while True:
        # Get input from user
        g = input("Type a number to compute square root, or press enter to close: ")

        # If user presses enter, exit the program
        if g == "":
            break

        # --Reprompting user if they give erroneous input--

        # The 'try' statement is super useful. It basically tells Python to try to do
        # something, and if that something would give an error,
        # then execute the 'except' statement. If however no errors are raised,
        # then just skip to the 'else' statement and keep going

        # Hey Python, try to convert the user's input to a float
        try:
            g = float(g)

        # If and only if doing the 'try' statement gives an error (e.g. the user gave a string),
        # then execute my 'except' statement. The 'else' statement gets disregarded.
        except:
            print("Sorry, that is not a number.")

        # If and only if there is no need to execute the 'except' statement
        # (i.e. no errors were raised when you did the 'try' statement),
        # then execute my 'else' statement
        else:
            estimate = g

            #loop that uses Newtons square root approximation algorithm and prints it

            while True:

                estimate = (estimate + g / estimate) / 2
                difference = abs(g-estimate ** 2)

                if difference <= tolerance:
                    break

            print(estimate)


        # The last few lines of the code you had are not needed as the user
        # will always get reprompted as to if they want to end the program


newton()