The TidBit Computer Store (Chapter 3, Project 10) has a credit plan for computer purchases. Inputs are the annual interest rate and the purchase price. Monthly payments are 5% of the listed purchase price, minus the down payment, which must be 10% of the purchase price.
Write a GUI-based program that displays labeled fields for the inputs and a text area for the output. The program should display a table, with appropriate headers, of a payment schedule for the lifetime of the loan. Each row of the table should contain the following items:

The month number (beginning with 1)
The current total balance owed
The interest owed for that month
The amount of principal owed for that month
The payment for that month
The balance remaining after payment
The amount of interest for a month is equal to balance * rate / 12. The amount of principal for a month is equal to the monthly payment minus the interest owed. Your program should include separate classes for the model and the view. The model should include a method that expects the two inputs as arguments and returns a formatted string for output by the GUI.
"""
Program: tidbit.py
Project 3.10

Print a payment schedule for a loan to purchase a computer.

Input
   purchase price

Constants
   annual interest rate = 12%
   downpayment = 10% of purchase price
   monthly payment = 5% of purchase price

"""

ANNUAL_RATE = .12
MONTHLY_RATE = ANNUAL_RATE / 12


purchasePrice = float(input("Enter the puchase price: "))

monthlyPayment = .05 * (purchasePrice - (.10 * purchasePrice))
month = 1
balance = purchasePrice
print("Month  Starting Balance  Interest to Pay  Principal to Pay  Payment  Ending Balance")
while balance > 0:
    if monthlyPayment > balance:
        monthlyPayment = balance
        interest = 0
    else:
        interest = balance * MONTHLY_RATE
    principal = monthlyPayment - interest
    remaining = balance - monthlyPayment
    print("%2d%15.2f%15.2f%17.2f%17.2f%17.2f" % \
          (month, balance, interest, principal, monthlyPayment, remaining))
    balance = remaining
    month += 1