python-accounting

Transactions in python-accounting follow a double-entry system using a Transaction object and one or more LineItem objects.

Workflow:

1. Create the Transaction object (e.g., CashSale, ClientInvoice, CashPurchase, SupplierBill, ClientReceipt, or JournalEntry).
2. session.add(transaction) and session.flush() to prepare it.
3. Create LineItem objects for the other side of the entry, specifying the account_id, amount, and optionally quantity and tax_id.
4. session.add(line_item) and session.flush().
5. Associate the line item with the transaction: transaction.line_items.add(line_item).
6. Crucial: Call transaction.post(session) to actually record the transaction in the Ledger.

from python_accounting.transactions import CashSale
from python_accounting.models import LineItem
from datetime import datetime 

# 1. Create Transaction
cash_sale = CashSale(
    narration="Cash Sale Transaction",
    transaction_date=datetime.now(),
    account_id=bank_account.id,
    entity_id=entity.id,
)
session.add(cash_sale)
session.flush() 

# 2. Create Line Item
cash_sale_line_item = LineItem(
    narration="Cash Sale line item",
    account_id=revenue_account.id,
    amount=100,
    tax_id=output_tax.id,
    entity_id=entity.id,
)
session.add(cash_sale_line_item)
session.flush()

# 3. Link and Post
cash_sale.line_items.add(cash_sale_line_item)
session.add(cash_sale)
cash_sale.post(session) # This posts the Transaction to the Ledger

A Compound Journal Entry is used when you need to post line item amounts to different sides of the ledger (some debits, some credits) within a single transaction.

To create a compound entry, you must:

1. Set compound=True on the JournalEntry.
2. Specify main_account_amount (the amount to be posted to the main account).
3. Use the credited property on individual LineItem objects to specify if that specific line item should be credited or debited (defaults to debit).

Critical Requirement: The total of all amounts posted to the debit side must exactly equal the total of all amounts posted to the credit side, otherwise the transaction will throw an error.

from datetime import datetime 
from python_accounting.models import Transaction, LineItem
from python_accounting.transactions import JournalEntry

# Setup a compound entry
journal_entry = JournalEntry(
    narration="Compound Transaction",
    transaction_date=datetime.now(),
    account_id=bank_account.id,
    entity_id=entity.id,
    compound=True, 
    credited=False, 
    main_account_amount=25, # Amount for the main account
)

# Line item that will be credited
client_item = LineItem(
    narration="Client item",
    account_id=client_account.id,
    credited=True, # Explicitly credit this account
    amount=30,
    entity_id=entity.id,
)

# Line item that will be debited (default)
supplier_item = LineItem(
    narration="Supplier item",
    account_id=supplier_account.id,
    amount=15,
    entity_id=entity.id,
)

# ... add to session and journal_entry.post(session)

A Tax Inclusive transaction is one where the tax amount is already included in the amount specified in the LineItem.

To implement this, follow the same procedure as a Tax Exclusive transaction, but you must explicitly set the tax_inclusive parameter to True on the LineItem object. The library will then back-calculate the base amount and the tax portion from the provided amount.

from datetime import datetime 
from python_accounting.models import Transaction, LineItem
from python_accounting.transactions import CashSale

# Assuming bank_account, revenue_account, output_tax, and entity are already initialized
with get_session(engine) as session:
    cash_sale = CashSale(
        narration="Cash Sale Transaction",
        transaction_date=datetime.now(),
        account_id=bank_account.id,
        entity_id=entity.id,
    )
    session.add(cash_sale)
    session.flush() 

    cash_sale_line_item = LineItem(
        narration="Cash Sale line item",
        account_id=revenue_account.id,
        amount=100,          # Total amount including tax
        tax_id=output_tax.id,
        tax_inclusive=True,  # <--- Enable Tax Inclusive mode
        entity_id=entity.id,
    )
    session.add(cash_sale_line_item)
    session.flush()

    cash_sale.line_items.add(cash_sale_line_item)
    session.add(cash_sale)
    cash_sale.post(session)

    # Results for a 10% tax rate:
    # bank_account balance increases by 100
    # revenue_account balance decreases by ~90.91 (100 / 1.1)
    # tax_account balance decreases by ~9.09

The Chart of Accounts is built by creating Account objects with specific account_type values. Common account types include:

• Account.AccountType.CONTROL (e.g., for Taxes)
• Account.AccountType.BANK (e.g., for Bank Accounts)
• Account.AccountType.OPERATING_REVENUE (e.g., for Revenue)
• Account.AccountType.RECEIVABLE (e.g., for Clients)
• Account.AccountType.PAYABLE (e.g., for Suppliers)
• Account.AccountType.OPERATING_EXPENSE (e.g., for Opex)
• Account.AccountType.DIRECT_EXPENSE (e.g., for Cost of Goods Sold)
• Account.AccountType.NON_CURRENT_ASSET (e.g., for Fixed Assets)

from python_accounting.models import Account

tax_account = Account(
    name="Tax Account",
    account_type=Account.AccountType.CONTROL,
    currency_id=currency.id,
    entity_id=entity.id,
)
bank_account = Account(
    name="Bank Account",
    account_type=Account.AccountType.BANK,
    currency_id=currency.id,
    entity_id=entity.id,
)
# ... add other accounts ...

session.add_all([
tax_account, 
bank_account, 
# ...
])
session.commit()