Working with decimals

[Seymore4Head]

I am trying to do this example:
http://openbookproject.net/pybiblio/practice/wilson/loan.php
The instructions warn that floating point math can get messy so I
cheated a little bit to get me going.

I made my program work by using numbers that wouldn't get messy.
Instead of using 6% interest I used 10 and instead of using 12 months,
I used 10.

I managed to get it working and formatted just like they wanted it,
but now I want to try to use any numbers.  It has been hard to figure
out which method to use.

Here is the working program.

import sys
count = 0
payment = 0
borrowed = 100
rate = 10
term = 10
interest=borrowed*rate*.01     #(*1)
balance = borrowed + interest
print ("Loan calculator")
print ("")
print ("Amount borrowed: ", borrowed)
print ("Interest rate: ", rate)
print ("Term: (months)", term)
print ("")
print ("Amount borrowed:" , borrowed)
print ("Total interest paid:" , interest)
print ("")
print ("")
print ("            Amount      Remaining")
print ("Pymt#        Paid        Balance")
print ("-----       ------       ----------")
while count <=term:


    print (repr(count).rjust(3), repr(payment).rjust(13),
repr(balance).rjust(14))


    payment = (borrowed + interest)/term
    balance = balance - payment
    count = count + 1

What should I use to make the formatting come out correctly when the
program prints "payment" and "balance" using decimal format?

If you change the "rate" from 10 to 6 and the "term" from 10 to 12,
the screen gets very messy.

Anyone care to suggest what method to use to fix the decimal format?