Managing Personal Finances using Python

Transcript

1. Managing Personal Finances using Python Siddhant Goel  /  @siddhantgoel PyMunich May 2019
2. Let's start with money.
3. 1. What is my net worth?
4. 2. What am I spending on?
5. 3. How much do I owe others?
6. How to debug this?
7. duckduckgo.com/?q=personal+ nance+apps Mint.com, YNAB, Outbank, Quickbooks, Zuper, GNUCash, ...
8. Proprietary ... mayyyyybe
9. -based ... sorry, that's not happening
10. Requirements Simple No cloud Ideally free Open source Hopefully Python
11. #plaintextaccounting
12. Double Entry Bookkeeping
13. beans ledger hledger beancount monescript
14. $ pip install beancount
15. Disclaimers I'm not a nancial advisor. Aim is to show you what's possible. Following slides may or may not contain some maths.
16. Accounts
18. Postings & Transactions
19. 2019-10-25 "*" "Überweisung BigCorp" Assets:DKB 3000.00 EUR Income:BigCorp -3000.00 EUR
20. ∑(postings) = 0
22. mkdir -p /home/morty/finances
23. siddhant@localhost ~/finances % tree . . ├── config.py ├── main.beancount ├── originals │ └── dkb │ └── 2019 │ ├── credit │ │ │── 01-jan.csv │ │ └── 02-feb.csv │ └── ec │ │── 01-jan.csv │ └── 02-feb.csv ├── poetry.lock └── pyproject.toml
24. Step 1: Download bank data (CSV)
25. Step 2: Convert .csv to .beancount
26. Step 3: Append everything to main.beancount
27. Step 4: Reports!
28. bean-check main.beancount
29. bean-report main.beancount balances siddhant@localhost ~/finances % bean-report main.beancount balances Assets:DKB 1450.00 EUR Income:BigCorp 3000.00 EUR Expenses:Rent -1500.00 EUR Expenses:Food 50.00 EUR
30. bean-query main.beancount SELECT month, SUM(position) FROM year = 2019 WHERE account ~ 'Expenses:Supermarket' GROUP BY month
31. $ pip install fava
34. main.beancount ; Date format - YYYY-MM-DD option "title" "Mustermann" option "operating_currency" "EUR" 2019-10-01 open Assets:DKB 2019-10-01 open Income:BigCorp 2019-10-01 open Expenses:Food 2019-10-01 open Expenses:Rent 2019-10-25 "*" "Überweisung BigCorp" Assets:DKB 3000.00 EUR Income:BigCorp -3000.00 EUR 2019-11-01 "*" "Miete" Assets:DKB -1500.00 EUR Expenses:Rent 1500.00 EUR 2019-11-02 "*" "Essen" Assets:DKB -50.00 EUR Expenses:Food 50.00 EUR 2019-10-26 balance Assets:DKB 3000.00 EUR 2019-11-03 balance Expenses:Food 50.00 EUR
35. config.py from beancount_dkb import ECImporter, CreditImporter CONFIG = ( ECImporter( 'DE99 9999 9999 9999 9999 99', 'Assets:DKB', 'EUR', file_encoding='ISO-8859-1', ), CreditImporter( '1234********5678', 'Assets:DKB', 'EUR', file_encoding='ISO-8859-1', ), )
36. Importers for German banks pypi.org/project/beancount-dkb pypi.org/project/beancount-ing-diba pypi.org/project/beancount-commerzbank
37. Sample Importer from beancount.core.amount import Amount from beancount.core.number import Number from beancount.ingest.importer import ImporterProtocol class SampleImporter(ImporterProtocol): # ... def identify(self, file_): """Check if file_ is from the bank we're supposed to work with """ # ... def extract(self, file_): """Read file_, and emit a list of beancount data structures """
38. Budgeting 2012-01-01 custom "budget" Expenses:Coffee "daily" 4.00 EUR 2013-01-01 custom "budget" Expenses:Books "weekly" 20.00 EUR 2014-02-10 custom "budget" Expenses:Groceries "monthly" 40.00 EUR 2015-05-01 custom "budget" Expenses:Electricity "quarterly" 85.00 EUR 2016-06-01 custom "budget" Expenses:Holiday "yearly" 2500.00 EUR
39. Resources https://plaintextaccounting.org https://www.reddit.com/r/plaintextaccounting https://awesome-beancount.com/ https://aumayr.github.io/beancount-docs-static/ https://beancount.github.io/fava/ Slides https://bit.ly/sg-pymunich-2019
40. Thanks for your time! bit.ly/sg-pymunich-2019  /  @siddhantgoel  sgoel.org