OsProject

OsProject
id	pynomina
state	active
owner	WolfgangFahl
title	pynomina
url	https://github.com/WolfgangFahl/pynomina
version	0.0.5
description	personal finance tool
date	2024-10-10
since	2024-10-06
until

Demo

https://nomina.bitplan.com

Introduction

pynomina is a personal finance tool designed to provide a flexible and enduring solution for managing financial records from diverse personal accounting tool sources. It aims to address the challenges of data conversion between different accounting software and ensure long-term readability of financial data. There is only limited support for the actual accounting tasks - this can be done much better by existing commercial and open source solutions. pynomina aims to give you the long-term freedom of choice between tools.

Motivation

In the past decades the author used different personal accounting tools:

The pain the conversion between those tools created was finally big enough to do something about it.

Goals

use a computer and human-readable ledger format that is ready to survive decades
convert from and to the formats of the tool of choice
allow for simple sanity checks and reports
allow for systematic tidy up
allow for integration into a larger organizational knowledge graph

Hub & Spoke Conversion

The pyNomina tool follows a Hub and Spoke model for conversion between different personal accounting file formats. The Ledger Book (YAML/JSON) format acts as the hub, with each supported format serving as a spoke. This setup simplifies conversions by allowing data to be transformed from any spoke to the hub and then to any other spoke format.

Supported Formats

Format	Type	Description	Wikidata Entry
Ledger Book YAML/JSON	Hub	Main format of pyNomina for converting between formats.	Ledger Book
Beancount	Spoke	A plaintext accounting format.	Beancount
GnuCash XML	Spoke	An XML-based format used by GnuCash.	GnuCash
Microsoft Money	Spoke	Zip File exported with mny_export script using mdb-tools	Microsoft Money
Finanzmanager Deluxe (QIF)	Spoke	A variant of QIF used by Finanzmanager Deluxe.	Finanzmanager Deluxe
Quicken Interchange Format	Spoke	Quicken Interchange Format (QIF)	Quicken
pyNomina Banking ZV YAML	Spoke	A format for exporting banking data in YAML or JSON.	Banking ZV

Installation

pip install pynomina
# alternatively if your pip is not a python3 pip
pip3 install pynomina 
# local install from source directory of pynomina 
pip install .

upgrade

pip install pynomina  -U
# alternatively if your pip is not a python3 pip
pip3 install pynomina -U

Usage

command line

nomina -h
usage: nomina [-h] [-a] [--apache APACHE] [-c] [-d]
              [--debugServer DEBUGSERVER] [--debugPort DEBUGPORT]
              [--debugRemotePath DEBUGREMOTEPATH]
              [--debugLocalPath DEBUGLOCALPATH] [-l] [-i INPUT] [-rol]
              [--host HOST] [--port PORT] [-s] [-V] [-v] [-rp ROOT_PATH]
              [--convert CONVERT] [--format {LB-YAML,GC-XML,BEAN}] [-o OUTPUT]

Personal finance tool

options:
  -h, --help            show this help message and exit
  -a, --about           show about info [default: False]
  --apache APACHE       create an apache configuration file for the given
                        domain
  -c, --client          start client [default: False]
  -d, --debug           show debug info [default: False]
  --debugServer DEBUGSERVER
                        remote debug Server
  --debugPort DEBUGPORT
                        remote debug Port
  --debugRemotePath DEBUGREMOTEPATH
                        remote debug Server path mapping - remotePath - path
                        on debug server
  --debugLocalPath DEBUGLOCALPATH
                        remote debug Server path mapping - localPath - path on
                        machine where python runs
  -l, --local           run with local file system access [default: False]
  -i INPUT, --input INPUT
                        input file
  -rol, --render_on_load
                        render on load [default: False]
  --host HOST           the host to serve / listen from [default: localhost]
  --port PORT           the port to serve from [default: 9849]
  -s, --serve           start webserver [default: False]
  -V, --version         show program's version number and exit
  -v, --verbose         show verbose output [default: False]
  -rp ROOT_PATH, --root_path ROOT_PATH
                        path to nomina files [default:
                        /Users/wf/Library/Python/3.12/lib/python/site-
                        packages/nomina_examples]
  --convert CONVERT     Convert the specified file to the desired format
  --format {LB-YAML,GC-XML,BEAN}
                        Output format for conversion [default: LB-YAML]
  -o OUTPUT, --output OUTPUT
                        Output file

command line conversion

There is a script test_cmdline that tries out some combinations of input and output file formats. see also Issue 7:command line conversion support

scripts/test_cmdline 
nomina_examples/empty.yaml →  /tmp/nomina/empty_converted.yaml: LB-YAML✅
nomina_examples/empty.yaml →  /tmp/nomina/empty_converted.gnucash: GC-XML✅
nomina_examples/empty.yaml →  /tmp/nomina/empty_converted.beancount: BEAN✅
...

starting as local webapp

nomina -s -l 
NiceGUI ready to go on http://localhost:9849

Tutorials

Quicken

Pynomina/Quicken

GnuCash

Pynomina/GnuCash

Beancount

Pynomina/Beancount

Microsoft Money

Pynomina/MsMoney

tickets

Testing

The testcases are python unittest modules see https://github.com/WolfgangFahl/pynomina/tree/main/tests. These tests are run as part of the continuous integration github actions To run the tests manually there is a "test" script in the scripts directory:

scripts/test 
Starting test test_read_bzv, debug=True ...
# Accounts: 3
# Transactions: 2
Date Range: 2024-10-06 to 2024-10-06
# Categories: 1
# Currencies: EUR: 2
Other Details:
  name: expenses2024
  owner: John Doe
test test_read_bzv, debug=True took   0.0 s
.Starting test test_conversions, debug=True ...
Converting Ledger Book None to GC-XML

...
Ran 17 tests in 4.518s

OK

Ledger Book

The pynomina Ledger Book model consists of four main classes:

Book
Account
Transaction
Split

These are the necessary classes which work together to represent a comprehensive financial ledger records.

Class Structure

Book

The Book class represents the main container for all financial data. It includes:

Basic information: name, owner, creation date, and source URL
Collections of accounts and transactions
Methods for managing accounts and transactions, including:
- get_stats(): Retrieves statistics about the book
- filter(): Filters transactions by date range
- create_account(): Creates a new account
- add_account(): Adds an account to the book
- lookup_account(): Finds an account by ID

Account

The Account class represents a hierarchy of individual financial accounts within the ledger. It includes:

account_id: Unique identifier for the account
name: Human-readable account name
account_type: Type of account (e.g., EXPENSE, INCOME)
description: Optional account description
currency: Account currency (default: EUR)
parent_account_id: Optional parent account for hierarchical structure

Transaction

The Transaction class represents individual financial transactions. It includes:

isodate: Date of the transaction in International Standards Organization date format yyyy-mm-dd
description: Description of the transaction
splits: List of Split objects representing the movement of money
payee: Optional payee information
memo: Optional additional notes
total_amount(): Method to calculate the total transaction amount

Split

The Split class represents the individual components of a transaction, showing how money moves between accounts. It includes:

amount: The amount of money involved in the split
account_id: The account associated with this part of the transaction
memo: Optional notes for this split
reconciled: Boolean indicating if the split has been reconciled

Example Data

Here's an example of how the ledger model is used in practice:

Yaml Format

owner: Wolfgang Fahl
url: https://github.com/WolfgangFahl/pynomina/blob/main/nomina_examples/expenses2024.yaml
since: 2024-10-06
accounts:
  Expenses:
    account_id: Expenses
    name: Expenses
    account_type: EXPENSE
    description: 'General Expenses'
    currency: EUR
  Expenses:Food:
    account_id: Expenses:Food
    name: Dining
    account_type: EXPENSE
    description: 'Expenses for Food'
    currency: EUR
    parent_account_id: Expenses
  Cash in wallet:
    account_id: Wallet
    name: Cash in Wallet
    account_type: EXPENSE
    description: ''
    currency: EUR
transactions:
  Bakery2024-10-06_0900_1:
    isodate: '2024-10-06'
    description: Bread
    splits:
      - amount: -3.50
        account_id: Cash in Wallet
      - amount: 3.50
        account_id: Expenses:Dining
        memo: Fresh sourdough bread
  Bakery2024-10-06_0900_2:
    isodate: '2024-10-06'
    description: Buns for Breakfast
    splits:
      - amount: -2.40
        account_id: Cash in Wallet
      - amount: 2.40
        account_id: Expenses:Dining
        memo: 4 whole grain buns

Implementation

The ledger model is implemented in Python, utilizing dataclasses and type hinting for clear and maintainable code. The `@lod_storable` decorator is used to enable easy serialization and deserialization of the data in YAML and/or JSON and other formats. The core idea is that the records should be readily available an tabular "list of dicts (lod)" format.

Pynomina

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