Managing Personal Finances using Python

Transcript

1. Managing Personal Finances using Python
   Siddhant Goel
    /  @siddhantgoel
   PyMunich October 2018
   

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2. Let's talk about money.
   

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3. What is my net worth?
   

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4. Where is my money going?
   

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5. How much do I owe others?
   

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6. Started questioning things earlier this year.
   

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7. Spend less
   Track more
   

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8. Number of solutions = O(∞)
   Mint.com
   YNAB
   Outbank
   GNUCash
   ...
   

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9. Proprietary
   ... mayyyyybe
   

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10. -based
    ... sorry, that's not happening
    

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11. Requirements
    Simple
    No cloud
    Ideally free
    Open source
    Hopefully Python
    

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12. #plaintextaccounting
    

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13. Double Entry Bookkeeping
    

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14. Beancount
    $ pip install beancount
    

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15. Big Fat Disclaimers ™
    I'm not a nancial advisor
    Aim is to show you the tip of the iceberg
    Next slide may or may not contain some maths
    

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16. ∑(postings) = 0
    

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19. ; Date format - YYYY-MM-DD
    option "title" "Mustermann"
    option "operating_currency" "EUR"
    2018-10-01 open Assets:DKB
    2018-10-01 open Income:BigCorp
    2018-10-01 open Expenses:Food
    2018-10-01 open Expenses:Rent
    ; ...
    ; ...
    ; ...
    2018-10-25 "*" "Überweisung BigCorp"
    Assets:DKB 3000.00 EUR
    Income:BigCorp -3000.00 EUR
    2018-11-01 "*" "Miete"
    Assets:DKB -1500.00 EUR
    Expenses:Rent 1500.00 EUR
    2018-11-02 "*" "Essen"
    Assets:DKB -50.00 EUR
    Expenses:Food 50.00 EUR
    2018-10-26 balance Assets:DKB 3000.00 EUR
    2018-11-03 balance Expenses:Food 50.00 EUR
    

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20. How to get started?
    

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21. Work ow
        
    

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22. Beancount does not understand your CSV
    les?
    Write an importer.
    

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23. 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
    """
    

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24. Fava: web UI for Beancount
    $ pip install fava
    

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27. Bean SQL
    SELECT
    month, SUM(position)
    FROM
    year = 2017
    WHERE
    account ~ 'Expenses:Supermarket'
    GROUP BY month
    

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28. What's next?
    Envelope Budgeting
    Automating Downloads
    

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29. Resources
    https://plaintextaccounting.org
    https://www.reddit.com/r/plaintextaccounting
    https://aumayr.github.io/beancount-docs-static/
    https://beancount.github.io/fava/
    Slides
    https://bit.ly/sg-pymunich-2018
    

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30. Thank you for your time!
     bit.ly/sg-pymunich-2018
     /  @siddhantgoel
     sgoel.org
    

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