Managing my expenses using Clojure
For someone who studied accounting, I've never really paid a huge amount of attention to where my money goes when I stop looking. Generally speaking, as long as I've got somewhere to live and a steady supply of cheese and wine I'm not too worried.
So it's funny that I suddenly decided that it would be a good idea to
track my expenses, but there you have it. I thought I'd write a little
Clojure program that would let me enter my recurring and one-off
expenses (in a format reminiscent of Emacs's
~/.diary file) and have
it tell me where all my money got to each week.
To use it, I create a file called
~/.expenses that looks roughly like
## Recurring stuff... # # Amounts we receive are entered as negative numbers... fortnightly -10000 Fortnightly pay (I wish) weekly 345.5 Rent (also optimistic) monthly 123 Internet+phone # Recurring items can have ranges attached to let you reflect changes # in amounts over time, etc. [--1/3/2009] monthly 123 Health cover [1/3/2009--] monthly 234 Health cover (the bastards!) fortnightly 50 Petrol yearly 2345 Gas & Electricity yearly 700 Car registration # etc... # One-off expenditures # 25/02/2009 11.00 Coffee 25/02/2009 9.50 Lunch 25/02/2009 25.00 Wine 26/02/2009 25.00 Wine 27/02/2009 25.00 Wine # ... more wine...
Then I point the expenses program at this file to see the report over time:
$ java -jar expenses.jar ~/.expenses ====================================================== Week starting: Sun Feb 22 00:00:00 EST 2009 ====================================================== Recurring items: 22/02/2009 Fortnightly pay (I wish) 5000.00 22/02/2009 Rent (also optimistic) ( 345.50) 22/02/2009 Internet+phone ( 30.75) 22/02/2009 Health cover ( 30.75) 22/02/2009 Petrol ( 25.00) 22/02/2009 Gas & Electricity ( 45.10) 22/02/2009 Car registration ( 13.46) Subtotal: 4509.44 Line items: 25/02/2009 Coffee ( 11.00) 25/02/2009 Lunch ( 9.50) 25/02/2009 Wine ( 25.00) 26/02/2009 Wine ( 25.00) 27/02/2009 Wine ( 25.00) Subtotal: ( 95.50) ========================= Total saved: 4413.94 =========================
Hooray! I'm fictitiously rich!
And that's basically all it does: it apportions recurring expenses over each week so you can get a more realistic idea of what they cost you week-to-week, and makes it easy to record one-off items too. For recording those one-offs I use a snippet of Emacs lisp which I bind to a key:
(defun spend () (interactive) (let ((now (time-stamp-dd/mm/yyyy)) (amount (read-number "Amount: ")) (description (read-string "Description?: "))) (with-current-buffer (find-file-noselect "~/.expenses") (goto-char (point-max)) (insert (format "%s\t%.2f\t%s\n" now amount description)) (save-buffer) (kill-buffer))))