Question

I was wondering if anyone could help me figure out why my program isn't compounding.
for month in range(1,13):
print 'Month: ' , str(month)
print 'Minimum monthly payment: ' , str(float(mmpr) * float(ob))
mmp = float(str(float(mmpr) * float(ob)))
print 'Interest payed: $' , str(float(air)/12 * float(ob))
ip = float(str(float(air)/12 * float(ob)))
print 'Principal payed: $' , str(float(mmp) - float(ip))
pp = float(str(float(mmp) - float(ip)))
print 'Ramaning balance: $' , str(float(ob) - float(pp))
rb = float(str(float(ob) - float(pp)))

Answer 1

In third line where you wrote:
print 'Minimum monthly payment: ' , str(float(mmpr) * float(ob))

mmpr is not defined (varable should be define before use

Answer 2

I ran out of chars the opening of the program reads:
##ob stands for outstand balance on the credit card
ob = float(raw_input('What is the outstanding balance on the credit card?'))
##air stands for anual interest rate
air = float(raw_input('What is the anual interest rate as a decimal?'))
##mmpr stands for minimum monthly payment rate
mmpr = float(raw_input('What is the minimum monthly payment rate as a decimal?')

I don't have a problem with anything coming up with an error, but when I run the program it doesn't compound. This is the print out I get the screen that I attached. As you can see every month it prints the same information rather than compounding the money.

I would greatly appreciate any help on this issue. Thanks so much!

Answer 3

I guess I should attach a prt scr of my program too.

Answer 4

copy python script codes at http://dpaste.com/ paste it then copy the address produced and paste it at your question

Answer 5

This is my code for minimum monthly payment problem. Try to figure out how it's working.
http://dpaste.com/784718/
In the loop you always do same calculations with same data, instead of this you shuld do same calculations with diferent (updatet with each loop cycle) data.

Answer 6

Sorry for the first stupid answer :)

The reason it is not working is that remaining balance should be the new outstanding balance so change the line :

rb = float(str(float(ob) - float(pp)))

to

ob = float(str(float(ob) - float(pp)))

then It start to work although the calculation needs to be checked also worth to use less code as below:

for month in range(1,13):
print 'Month: ' , str(month)

mmp = float(str(float(mmpr) * float(ob)))
print 'Minimum monthly payment: ' , str(mmp)

ip = float(str(float(air)/12 * float(ob)))
print 'Interest to be paied: $' , str(ip)

pp = float(str(float(mmp) - float(ip)))
print 'Principal paied: $' , str(pp)

ob = float(str(float(ob) - float(pp)))
print 'Ramaning balance: $' , str(ob)

Answer 7

http://dpaste.com/hold/784997/

Answer 8

Thank you so much Shahrouz!! I greatly appreciate your help. Thanks to everyone else that helped me as welll!
<3