Question

I need some help with this piece of code!


month=0
debt=5,000
payment=100
interest=73.50
while month<12:
debt -= payment
debt -= interest
print debt


It is telling me that -= is not valid.
What am I doing wrong.

Answer 1

Read the error message the interpreter is giving you closely. The clue you need is in there.

Answer 2

debt = 5,000 # wrong
debt = 5000 # right

Answer 3

a la python shell you are creating a tuple and then trying to += (concatenate) an int to it

>>> debt=5,000
>>> debt
(5, 0)
>>> debt+=100

Traceback (most recent call last):
File "<pyshell#253>", line 1, in <module>
debt+=100
TypeError: can only concatenate tuple (not "int") to tuple

as rsmith said above, get rid of the ','

Answer 4

Don't forget that you never increase the value of month, your loop is endeless, never separate the numbers, only if they are floats. Remember also that, the interest are part of your payment, should be better if it looks like this: debt = debt - (payment+interest), that'll help if they ask you things like, total amount you paid.