Models

Design

The core models consist of:

  • Account - Such as ‘Accounts Receivable’, a bank account, etc. Accounts can be arranged as a tree structure, where the balance of the parent account is the summation of the balances of all its children.
  • Transaction - Represents a movement between accounts. Each transaction must have two or more legs.
  • Leg - Represents a flow of money into (debit) or out of (credit) a transaction. Debits are represented by negative amounts, and credits by positive amounts. The sum of all a transaction’s legs must equal zero. This is enforced with a database constraint.

Additionally, there are models which related to the import of external bank statement data:

  • StatementImport - Represents a simple import of zero or more statement lines relating to a specific Account.
  • StatementLine - Represents a statement line. StatementLine.create_transaction() may be called to create a transaction for the statement line.

Account

class hordak.models.Account(*args, **kwargs)

Represents an account

An account may have a parent, and may have zero or more children. Only root accounts can have a type, all child accounts are assumed to have the same type as their parent.

An account’s balance is calculated as the sum of all of the transaction Leg’s referencing the account.

uuid

SmallUUID

UUID for account. Use to prevent leaking of IDs (if desired).

name

str

Name of the account. Required.

parent

Account|None

Parent account, nonen if root account

code

str

Account code. Must combine with account codes of parent accounts to get fully qualified account code.

type

str

Type of account as defined by Account.TYPES. Can only be set on root accounts. Child accounts are assumed to have the same time as their parent.

TYPES

Choices

Available account types. Uses Choices from django-model-utils. Types can be accessed in the form Account.TYPES.asset, Account.TYPES.expense, etc.

is_bank_account

bool

Is this a bank account. This implies we can import bank statements into it and that it only supports a single currency.

classmethod validate_accounting_equation()

Check that all accounts sum to 0

full_code

Get the full code for this account

Do this by concatenating this account’s code with that of all the parent accounts.

sign

Returns 1 if a credit should increase the value of the account, or -1 if a credit should decrease the value of the account.

This is based on the account type as is standard accounting practice. The signs can be derrived from the following expanded form of the accounting equation:

Assets = Liabilities + Equity + (Income - Expenses)

Which can be rearranged as:

0 = Liabilities + Equity + Income - Expenses - Assets

Further details here: https://en.wikipedia.org/wiki/Debits_and_credits

balance(as_of=None, raw=False, **kwargs)

Get the balance for this account, including child accounts

Parameters:
  • as_of (Date) – Only include transactions on or before this date
  • raw (bool) – If true the returned balance should not have its sign adjusted for display purposes.
  • **kwargs (dict) – Will be used to filter the transaction legs
Returns:

Balance

See also

simple_balance()

simple_balance(as_of=None, raw=False, **kwargs)

Get the balance for this account, ignoring all child accounts

Parameters:
  • as_of (Date) – Only include transactions on or before this date
  • raw (bool) – If true the returned balance should not have its sign adjusted for display purposes.
  • **kwargs (dict) – Will be used to filter the transaction legs
Returns:

Balance
transfer_to(to_account, amount, **transaction_kwargs)

Create a transaction which transfers amount to to_account

This is a shortcut utility method which simplifies the process of transferring between accounts.

Parameters:
  • to_account (Account) – The destination account
  • amount (Money) – The amount to be transferred

Transaction

class hordak.models.Transaction(*args, **kwargs)

Represents a transaction

A transaction is a movement of funds between two accounts. Each transaction will have two or more legs, each leg specifies an account and an amount.

See also

Account.transfer_to() is a useful shortcut to avoid having to create transactions manually.

Examples

You can manually create a transaction as follows:

from django.db import transaction as db_transaction
from hordak.models import Transaction, Leg

with db_transaction.atomic():
    transaction = Transaction.objects.create()
    Leg.objects.create(transaction=transaction, account=my_account1, amount=Money(100, 'EUR'))
    Leg.objects.create(transaction=transaction, account=my_account2, amount=Money(-100, 'EUR'))
uuid

SmallUUID

UUID for transaction. Use to prevent leaking of IDs (if desired).

timestamp

datetime

The datetime when the object was created.

date

date

The date when the transaction actually occurred, as this may be different to timestamp.

description

str

Optional user-provided description

Leg

class hordak.models.Leg(*args, **kwargs)

The leg of a transaction

Represents a single amount either into or out of a transaction. All legs for a transaction must sum to zero, all legs must be of the same currency.

uuid

SmallUUID

UUID for transaction leg. Use to prevent leaking of IDs (if desired).

transaction

Transaction

Transaction to which the Leg belongs.

account

Account

Account the leg is transferring to/from.

amount

Money

The amount being transferred

description

str

Optional user-provided description

type

str

hordak.models.DEBIT or hordak.models.CREDIT.

StatementImport

class hordak.models.StatementImport(*args, **kwargs)

Records an import of a bank statement

uuid

SmallUUID

UUID for statement import. Use to prevent leaking of IDs (if desired).

timestamp

datetime

The datetime when the object was created.

bank_account

Account

The account the import is for (should normally point to an asset account which represents your bank account)

StatementLine

class hordak.models.StatementLine(*args, **kwargs)

Records an single imported bank statement line

A StatementLine is purely a utility to aid in the creation of transactions (in the process known as reconciliation). StatementLines have no impact on account balances.

However, the StatementLine.create_transaction() method can be used to create a transaction based on the information in the StatementLine.

uuid

SmallUUID

UUID for statement line. Use to prevent leaking of IDs (if desired).

timestamp

datetime

The datetime when the object was created.

date

date

The date given by the statement line

statement_import

StatementImport

The import to which the line belongs

amount

Decimal

The amount for the statement line, positive or nagative.

description

str

Any description/memo information provided

transaction

Transaction

Optionally, the transaction created for this statement line. This normally occurs during reconciliation. See also StatementLine.create_transaction().

is_reconciled

Has this statement line been reconciled?

Determined as True if transaction has been set.

Returns:True if reconciled, False if not.
Return type:bool
create_transaction(to_account)

Create a transaction for this statement amount and account, into to_account

This will also set this StatementLine’s transaction attribute to the newly created transaction.

Parameters:to_account (Account) – The account the transaction is into / out of.
Returns:The newly created (and committed) transaction.
Return type:Transaction