600-2-1.py

balance = float(raw_input("Enter the outstanding amount on your credit card: "))
interest_rate = float(raw_input("Enter the annual credit card interest rate as a decimal: "))
payment_rate = float(raw_input("Enter the minimum monthly payment rate as a decimal: "))

total_payment = 0

for month in xrange(1, 13): # (xrange? like range, but usually better.)
    payment = round(payment_rate * balance, 2)
    interest_paid = round((interest_rate / 12.0) * balance, 2)
    principal_paid = payment - interest_paid
    balance = balance - principal_paid
    total_payment += payment


    print "Month: %s" % month
    print "Minimum monthly payment: $%s" % payment
    print "Principal paid: $%s" % principal_paid
    print "Remaining balance: $%s" % balance

print "RESULT"
print "Total amount paid: $%s" % total_payment
print "Remaining balance: $%s" % balance