Как правильно передать данные JSON с декодируемой структурой в UserDefaults

Пожалуйста, проверьте ниже код, сообщите мне, если он работает.

#!/usr/bin/env python3

    # display a welcome message
    print("Welcome to the Future Value Calculator")
    print()

    choice = "y"
    while choice.lower() == "y":

        # get input from the user
        while True:
            monthly_investment = float(input("Enter monthly investment:  "))
            if monthly_investment <= 0 :
                print("Entry must be greater than 0 . Please try again.")
                continue
            else:
                break

        while True:
            yearly_interest_rate = float(input("Enter yearly interest rate:  "))
            if yearly_interest_rate <= 0  or yearly_interest_rate >= 15:
                print("Entry must be greater than 0 and less than or equal to 15. Please try again.")
                continue
            else:
                break

        while True:
            years = int(input("Enter number of years: "))
            if years <= 0 or years >= 50:
                print("Entry must be greater than 0 and less than or equal to 50")
                continue
            else:
                break

         # convert yearly values to monthly values
        monthly_interest_rate = yearly_interest_rate / 12 / 100
        months = years * 12

        # calculate the future value
        future_value = 0
        for i in range(1,months+1):
            future_value += monthly_investment
            monthly_interest_amount = future_value * monthly_interest_rate
            future_value += monthly_interest_amount
            if i % 12 ==0:
            # display the result
                print("Year = {0} Future value:\t{1}".format(i//12,str(round(future_value, 2))))



        # see if the user wants to continue
        choice = input("Continue (y/n)? ")
        print()

    print("Bye!")