simplebooks 0.3.0

Simple double-entry accounting system using sqloquent for data storage.

SimpleBooks

SimpleBooks is a simple accounting library that uses sqloquent to persist data for identities, ledgers, accounts, transactions, and entries. Included are tools for accomplishing basic bookkeeping tasks. The basic accounting formula is this: Assets = Liabilities + Equity. Assets are debit-balance; liabilities and equity are credit-balance. Every transaction must have entries that have no net difference between the amount of credits and the amount of debits.

This is a simplification of bookchain: all cryptographic features have been removed. This may be useful in scenarios when cryptographic features cannot be supported.

Status

All initially planned features have been implemented and tested.

Open issues can be found here.

Previous changes can be found in the changelog.

The async implementation has an upstream issue from the sqloquent dependency that can be tracked here. Once that is fixed, the dependency will be updated, and this notice will be removed.

Overview

This library provides an accounting system using sqloquent for persistence, packify for deterministic encoding, and the classic rules of double-entry bookkeeping. The Transaction.prepare and Transaction.validate ensure that the accounting rule is followed.

Class organization

Currency represents a currency/unit of account for a Ledger. It includes the number of subunits to track and optionally the base for conversion to decimal (defaults to 10), FX symbol, prefix symbol, and/or postfix symbol to be used with the format method (e.g. USD.format(1200) could result in "12.00 USD", "$12.00", or "12.00$", respectively). It also includes to_decimal method for formatting int amounts into Decimals, and get_units method for getting a tuple of whole units and remainders.

Identity represents a legal person or other entity that can sign contracts or engage in transactions. It includes the name, details, and optionally public key bytes and private key seed bytes.

Ledger represents a general ledger for a given Identity using a specific Currency. It includes a name, a LedgerType, the Identity id, and the Currency id. LedgerType is an enum representing the valid ledger types, either PRESENT or FUTURE for cash and accrual accounting, respectively, or for other uses the package user may define.

Account represents an account for a given Ledger. It includes a name, a type (one of the AccountType enum options), the Ledger id, an optional locking script for access control, and optional details.

AccountCategory represents a category for Accounts. It includes a name, a LedgerType, and a destination (str description; e.g. "Balance Sheet" or "Profit and Loss").

AccountType is an enum representing the valid account types. The options are DEBIT_BALANCE, ASSET, CONTRA_ASSET, CREDIT_BALANCE, LIABILITY, EQUITY, CONTRA_LIABILITY, and CONTRA_EQUITY.

Entry represents an entry in the general ledger for a given Account. It includes a type (one of the EntryType enum options), an amount, a nonce, the Account id, and optional details.

EntryType is an enum representing the valid entry types. The options are CREDIT and DEBIT.

Transaction represents a transaction made of Entrys. It includes the Entry ids, Ledger ids, a timestamp, and the details. Each Transaction must include entries that balance the number of credits and debits applied to each ledger affected by the transaction. Use Transaction.prepare to prepare a transaction -- it will raise validation errors if the transaction is not valid -- then call .save() on the result to persist it to the database. Transactions in the database can be validated by using .validate(), which will return True if it is valid and False if it is not (it will also raise errors in some situations that require more information about the validation failure).

Statement represents the balances of all accounts of a Ledger at a particular point in time. It allows trimming/archiving of entries/txns while maintaining the effects of those entries/txns. It can be used either to summarize just the txns it contains or also calculate balances starting with the balances of a previous Statement, but the latter is the standard behavior. Also contains a height column that is incremented with each subsequent Statement when using the prepare method.

Customer and Vendor are provided in case they are useful in some way, but no relations are set up for them currently. This is likely to change in a future release.

• Identity has many Ledgers
• Currency has many Ledgers
• Ledger
  • Belongs to Identity and Currency
  • Has many Accounts and Statements
  • Is within Transactions and ArchivedTransactions
• Account
  • Belongs to Ledger and AccountCategory
  • Has many Entrys and ArchivedEntrys
• AccountCategory has many Accounts
• Entry
  • Belongs to Account
  • Is within Transactions
• Transaction contains Ledgers and Entrys
• ArchivedEntry
  • Is within ArchivedTransactions
  • Belongs to Account
• ArchivedTransaction
  • Contains ArchivedEntrys and Ledgers
  • Is within Statements
• Statement
  • Belongs to Ledger
  • Contains Transactions and ArchivedTransactions

Installation and Setup

Install with pip install simplebooks. If you want to use the async version, instead install with pip install simplebooks[asyncql].

Once installed, use the following to setup your project as appropriate:

import simplebooks

simplebooks.publish_migrations(path_to_migrations_folder)
simplebooks.automigrate(path_to_migrations_folder, db_file_path)
simplebooks.set_connection_info(db_file_path)

To use the async version:

import simplebooks
import simplebooks.asyncql

simplebooks.publish_migrations(path_to_migrations_folder)
simplebooks.automigrate(path_to_migrations_folder, db_file_path)
simplebooks.asyncql.set_connection_info(db_file_path)

The simplebooks.publish_migrations function can be passed a callback that takes the str model name and str migration file contents, and returns the modified str migration file contents. This can be used to modify the migration file contents before they are written to disk. For example, if you wanted to modify the Account migration file to add a unique constraint to the name column, you could do the following:

def migration_callback(name: str, m: str) -> str:
    if name == 'Account':
        return m.replace("t.text('name').index()", "t.text('name').unique()")
    return m

simplebooks.publish_migrations(path_to_migrations_folder, migration_callback)

More Resources

Documentation generated by autodox can be found here. Docs for the async version can be found here.

Check out the Pycelium discord server. If you experience a problem, please discuss it on the Discord server. All suggestions for improvement are also welcome, and the best place for that is also Discord. If you experience a bug and do not use Discord, open an issue on Github.

Tests

There are a total of 9 tests (4 e2e tests and 5 tests for miscellaneous tools/features). To run them, clone the repo, set up a virtual environment (e.g. python -m venv venv && source venv/bin/activate), install the dependencies with pip install -r requirements.txt, and then run the following: find tests -name test_*.py -print -exec python {} \;. On Windows, the 5 test files will have to be individually run with the following:

python tests/test_async_basic_e2e.py
python tests/test_async_statements_e2e.py
python tests/test_basic_e2e.py
python tests/test_misc.py
python tests/test_statements_e2e.py

Personal, Non-commercial Use License

Copyright (c) 2025 Jonathan Voss (k98kurz)

Permission to use, copy, modify, and/or distribute this software for any personal, non-commercial purpose is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. For other uses, contact the software author.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.