template: Template amounts are now written with fuller expressions.

This makes it possible to support transactions that divide funds in
ways other than a simple percentage split.  For example, there
might be tax withheld, or a flat fee expense on each transaction.
This commit is contained in:
Brett Smith 2017-11-09 12:18:20 -05:00
parent cebd1481ec
commit 3b821cbbee
8 changed files with 231 additions and 96 deletions

View file

@ -24,15 +24,15 @@ Writing templates
A template looks like a Ledger entry with a couple of differences:
* You don't write the first payee line.
* You allocate percentages to each account, rather than specific currency amounts.
* Instead of writing specific currency amounts, you write simple expressions to calculate amounts.
Here's a simple template for Patreon patron payments::
[DEFAULT]
template patreon income =
;Tag: Value
Income:Patreon -100%%
Accrued:Accounts Receivable:Patreon 100%%
Income:Patreon -{amount}
Accrued:Accounts Receivable:Patreon {amount}
Let's walk through this line by line.
@ -42,12 +42,41 @@ Every setting in your configuration file has to be in a section. ``[DEFAULT]``
The first line of the template is a Ledger tag. The program will leave all kinds of tags and Ledger comments alone, except to indent them nicely.
The next two lines split the money across accounts. They follow almost the same format as they do in Ledger: there's an account named, followed by a tab or two or more spaces, and then an amount. However, rather than a currency amount, specify a percentage amount between -100% and 100%. You can specify any number of splits you want, as long as the negative splits total -100% and the positive splits total 100%. ``%`` is a special character in INI file syntax; writing ``%%`` is the way to get a literal ``%`` in the string. Alternatively, you can omit the ``%`` altogether; import2ledger will still treat any floating point value at the end of the line as a percentage.
The next two lines split the money across accounts. They follow almost the same format as they do in Ledger: there's an account named, followed by a tab or two or more spaces, and then an expression. Each time import2ledger generates an entry, it will evaluate this expression using the data it imported to calculate the actual currency amount to write. Your expression can use numbers, basic arithmetic operators (including parentheses for grouping), and imported data referred to as ``{variable_name}``.
If the amount of currency being imported doesn't split evenly, spare change will be allocated to the last split to keep the entry balanced.
import2ledger uses decimal math to calculate each amount, and rounds to the number of digits appropriate for that currency. If the amount of currency being imported doesn't split evenly, spare change will be allocated to the last split to keep the entry balanced on both sides.
Refer to the `Python documentation for INI file structure <https://docs.python.org/3/library/configparser.html#supported-ini-file-structure>`_ for full details of the syntax. Note that import2ledger doesn't use ``;`` as a comment prefix, since that's the primary comment prefix in Ledger.
Template variables
~~~~~~~~~~~~~~~~~~
import2ledger templates have access to a few variables for each transaction that can be included anywhere in the entry, not just amount expressions. In other parts of the entry, they're treated as strings, and you can control their formatting using `Python's format string syntax <https://docs.python.org/3/library/string.html#formatstrings>`_. For example, this template sets different payees for each side of the transaction::
template patreon income =
Income:Patreon -{amount}
;Payee: {payee}
Accrued:Accounts Receivable:Patreon {amount}
;Payee: Patreon
Every template can use the following variables:
================== ==========================================================
Name Contents
================== ==========================================================
amount The total amount of the transaction, as a simple decimal
number (not currency-formatted)
------------------ ----------------------------------------------------------
currency The three-letter code for the transaction currency
------------------ ----------------------------------------------------------
date The date of the transaction, in your configured output
format
------------------ ----------------------------------------------------------
payee The name of the transaction payee
================== ==========================================================
Specific importers and hooks may provide additional variables.
Supported templates
~~~~~~~~~~~~~~~~~~~
@ -70,40 +99,14 @@ Patreon
This template can use these variables:
``country_name``
The full name of the country VAT was withheld for
``country_code``
The two-letter ISO country code of the country VAT was withheld for
Template variables
~~~~~~~~~~~~~~~~~~
import2ledger templates have access to a few variables for each transaction that can be included in the output entry using `Python's format string syntax <https://docs.python.org/3/library/string.html#formatstrings>`_. For most uses, all you need to do is write ``{variable_name}`` in the template, and the variable's value will be filled in there. For example, this template sets different payees for each side of the transaction::
template patreon income =
Income:Patreon -100%%
;Payee: {payee}
Accrued:Accounts Receivable:Patreon 100%%
;Payee: Patreon
You can use the following variables:
================== ==========================================================
============== ============================================================
Name Contents
================== ==========================================================
amount The total amount of the transaction, as a simple decimal
number (not currency-formatted)
------------------ ----------------------------------------------------------
currency The three-letter code for the transaction currency
------------------ ----------------------------------------------------------
date The date of the transaction, in your configured output
format
------------------ ----------------------------------------------------------
payee The name of the transaction payee
================== ==========================================================
Custom hooks may add more template variables.
============== ============================================================
country_name The full name of the country VAT was withheld for
-------------- ------------------------------------------------------------
country_code The two-letter ISO country code of the country VAT was
withheld for
============== ============================================================
Other output options
~~~~~~~~~~~~~~~~~~~~
@ -112,6 +115,8 @@ Various options control how import2ledger formats dates and currency amounts. R
date_format = %%Y-%%m-%%d
(``%`` is a special character in the configuration file syntax. ``%%`` represents a literal percent sign.)
Configuration sections
~~~~~~~~~~~~~~~~~~~~~~

View file

@ -241,6 +241,7 @@ class Configuration:
signed_currencies=[code.strip().upper() for code in section_config['signed_currencies'].split(',')],
signed_currency_fmt=section_config['signed_currency_format'],
unsigned_currency_fmt=section_config['unsigned_currency_format'],
template_name=config_key,
)
def setup_logger(self, logger, section_name=None):

View file

@ -1,49 +1,153 @@
import collections
import datetime
import decimal
import functools
import io
import operator
import re
import tokenize
import babel.numbers
class AccountSplitter:
Split = collections.namedtuple('Split', ('account', 'percentage'))
from . import errors
def __init__(self, sign, signed_currencies, signed_currency_fmt, unsigned_currency_fmt):
self.splits = []
self.sign = sign
class TokenTransformer:
def __init__(self, source):
try:
source = source.readline
except AttributeError:
pass
self.in_tokens = tokenize.tokenize(source)
@classmethod
def from_bytes(cls, b):
return cls(io.BytesIO(b).readline)
@classmethod
def from_str(cls, s, encoding='utf-8'):
return cls.from_bytes(s.encode(encoding))
def __iter__(self):
for ttype, tvalue, _, _, _ in self.in_tokens:
try:
transformer = getattr(self, 'transform_' + tokenize.tok_name[ttype])
except AttributeError:
raise ValueError("{} token {!r} not supported".format(ttype, tvalue))
yield from transformer(ttype, tvalue)
def _noop_transformer(self, ttype, tvalue):
yield (ttype, tvalue)
transform_ENDMARKER = _noop_transformer
def transform_ENCODING(self, ttype, tvalue):
self.in_encoding = tvalue
return self._noop_transformer(ttype, tvalue)
def transform(self):
out_bytes = tokenize.untokenize(self)
return out_bytes.decode(self.in_encoding)
class AmountTokenTransformer(TokenTransformer):
SUPPORTED_OPS = frozenset('+-*/()')
transform_NAME = TokenTransformer._noop_transformer
def transform_NUMBER(self, ttype, tvalue):
yield (tokenize.NAME, 'Decimal')
yield (tokenize.OP, '(')
yield (tokenize.STRING, repr(tvalue))
yield (tokenize.OP, ')')
def transform_OP(self, ttype, tvalue):
if tvalue == '{':
try:
name_type, name_value, _, _, _ = next(self.in_tokens)
close_type, close_value, _, _, _ = next(self.in_tokens)
if (name_type != tokenize.NAME
or close_type != tokenize.OP
or close_value != '}'):
raise ValueError()
except (StopIteration, ValueError):
raise ValueError("opening { does not name variable")
yield (tokenize.NAME, name_value)
elif tvalue in self.SUPPORTED_OPS:
yield from self._noop_transformer(ttype, tvalue)
else:
raise ValueError("unsupported operator {!r}".format(tvalue))
class AccountSplitter:
def __init__(self, signed_currencies, signed_currency_fmt, unsigned_currency_fmt,
template_name):
self.splits = collections.OrderedDict()
self.signed_currency_fmt = signed_currency_fmt
self.unsigned_currency_fmt = unsigned_currency_fmt
self.signed_currencies = set(signed_currencies)
self.unsplit = sign * 100
self.template_name = template_name
self._last_template_vars = object()
def add(self, account, percentage_s):
int_pctage = decimal.Decimal(percentage_s.rstrip('%'))
self.unsplit -= int_pctage
percentage = None if self.unsplit == 0 else (int_pctage / 100)
self.splits.append(self.Split(account, percentage))
def add(self, account, amount_expr):
try:
clean_expr = AmountTokenTransformer.from_str(amount_expr).transform()
except ValueError as error:
raise errors.UserInputConfigurationError(error.args[0], amount_expr)
self.splits[account] = compile(clean_expr, self.template_name, 'eval')
def _currency_decimal(self, amount, currency):
return decimal.Decimal(babel.numbers.format_currency(amount, currency, '###0.###'))
def _balance_amounts(self, amounts, to_amount):
cmp_func = operator.lt if to_amount > 0 else operator.gt
should_balance = functools.partial(cmp_func, 0)
remainder = to_amount
to_account = None
for account, amount in amounts.items():
if should_balance(amount):
remainder -= amount
to_account = account
if to_account is None:
pass
elif (abs(remainder) / abs(to_amount)) >= decimal.Decimal('.1'):
raise errors.UserInputConfigurationError(
"template can't balance amounts to {}".format(to_amount),
self.template_name,
)
else:
amounts[to_account] += remainder
def _build_amounts(self, template_vars):
amount_vars = {k: v for k, v in template_vars.items() if isinstance(v, decimal.Decimal)}
amount_vars['Decimal'] = decimal.Decimal
amounts = collections.OrderedDict(
(account, self._currency_decimal(eval(amount_expr, amount_vars),
template_vars['currency']))
for account, amount_expr in self.splits.items()
)
self._balance_amounts(amounts, template_vars['amount'])
self._balance_amounts(amounts, -template_vars['amount'])
return amounts
def _iter_splits(self, template_vars):
amounts = self._build_amounts(template_vars)
if template_vars['currency'] in self.signed_currencies:
amt_fmt = self.signed_currency_fmt
else:
amt_fmt = self.unsigned_currency_fmt
for account, amount in amounts.items():
amt_s = babel.numbers.format_currency(amount, template_vars['currency'], amt_fmt)
yield ' {:45} {:>19}\n'.format(account, amt_s)
def render_next(self, template_vars):
try:
account, percentage = next(self._split_iter)
except (AttributeError, StopIteration):
self._split_iter = iter(self.splits)
account, percentage = next(self._split_iter)
self._remainder = self.sign * template_vars['amount']
self._currency = template_vars['currency']
if self._currency in self.signed_currencies:
self._amt_fmt = self.signed_currency_fmt
else:
self._amt_fmt = self.unsigned_currency_fmt
if percentage is None:
amount = self._remainder
else:
amount = decimal.Decimal(babel.numbers.format_currency(
template_vars['amount'] * percentage, self._currency, '###0.###'))
self._remainder -= amount
amt_s = babel.numbers.format_currency(amount, self._currency, self._amt_fmt)
return ' {:45} {:>19}\n'.format(account, amt_s)
if template_vars is not self._last_template_vars:
self._split_iter = self._iter_splits(template_vars)
self._last_template_vars = template_vars
return next(self._split_iter)
class Template:
ACCOUNT_SPLIT_RE = re.compile(r'(?:\t| )\s*')
DATE_FMT = '%Y/%m/%d'
SIGNED_CURRENCY_FMT = '¤#,##0.###;¤-#,##0.###'
UNSIGNED_CURRENCY_FMT = '#,##0.### ¤¤'
@ -51,12 +155,11 @@ class Template:
def __init__(self, template_s, signed_currencies=frozenset(),
date_fmt=DATE_FMT,
signed_currency_fmt=SIGNED_CURRENCY_FMT,
unsigned_currency_fmt=UNSIGNED_CURRENCY_FMT):
unsigned_currency_fmt=UNSIGNED_CURRENCY_FMT,
template_name='<template>'):
self.date_fmt = date_fmt
self.pos_splits = AccountSplitter(
1, signed_currencies, signed_currency_fmt, unsigned_currency_fmt)
self.neg_splits = AccountSplitter(
-1, signed_currencies, signed_currency_fmt, unsigned_currency_fmt)
self.splitter = AccountSplitter(
signed_currencies, signed_currency_fmt, unsigned_currency_fmt, template_name)
lines = [s.lstrip() for s in template_s.splitlines(True)]
for index, line in enumerate(lines):
@ -72,10 +175,14 @@ class Template:
if line[0].isalpha():
if start_index < index:
self._add_str_func(lines[start_index:index])
account, percentage_s = line.rsplit(None, 1)
splitter = self.neg_splits if percentage_s.startswith('-') else self.pos_splits
splitter.add(account, percentage_s)
self.format_funcs.append(splitter.render_next)
line = line.strip()
match = self.ACCOUNT_SPLIT_RE.search(line)
if match is None:
raise errors.UserInputError("no amount expression found", line)
account = line[:match.start()]
amount_expr = line[match.end():]
self.splitter.add(account, amount_expr)
self.format_funcs.append(self.splitter.render_next)
start_index = index + 1
if start_index <= index:
self._add_str_func(lines[start_index:])

View file

@ -1,22 +1,29 @@
[Simplest]
template =
Accrued:Accounts Receivable 100%%
Income:Donations -100%%
Accrued:Accounts Receivable {amount}
Income:Donations -{amount}
[FiftyFifty]
template =
Accrued:Accounts Receivable 100%%
Income:Donations -50%%
Income:Sales -50%%
Accrued:Accounts Receivable {amount}
Income:Donations -.5 * {amount}
Income:Sales -.5*{amount}
[Complex]
template =
;Tag: Value
;TransactionID: {txid}
Accrued:Accounts Receivable 100%%
Accrued:Accounts Receivable {amount}
;Entity: Supplier
Income:Donations:Specific -95.5%%
Income:Donations:Specific -.955* {amount}
;Program: Specific
;Entity: {entity}
Income:Donations:General -4.5%%
Income:Donations:General -.045 * {amount}
;Entity: {entity}
[Multivalue]
template =
Expenses:Taxes {tax}
Accrued:Accounts Receivable {amount} - {tax}
Income:RBI -.1*{amount}
Income:Donations -.9*{amount}

View file

@ -5,15 +5,15 @@ signed_currencies = EUR
[Templates]
output_path = Template.output
one =
Accrued:Accounts Receivable 100%%
Income:Donations -100%%
Accrued:Accounts Receivable {amount}
Income:Donations -{amount}
two =
;Tag1: {value}
Income:Donations -100%%
Income:Donations -{amount}
;IncomeTag: Donations
Expenses:Fundraising 5%%
Expenses:Fundraising .05 * {amount}
;ExpenseTag: Fundraising
Accrued:Accounts Receivable 95%%
Accrued:Accounts Receivable .95 * {amount}
;AccrualTag: Receivable
[Date]

View file

@ -5,8 +5,8 @@ signed_currencies = USD
[One]
template patreon cardfees =
Accrued:Accounts Receivable -100%%
Expenses:Fees:Credit Card 100%%
Accrued:Accounts Receivable -{amount}
Expenses:Fees:Credit Card {amount}
template patreon svcfees =
Accrued:Accounts Receivable -100%%
Expenses:Fundraising 100%%
Accrued:Accounts Receivable -{amount}
Expenses:Fundraising {amount}

View file

@ -31,6 +31,7 @@ def test_defaults():
assert kwargs == {
'date_fmt': '%Y-%m-%d',
'signed_currency_fmt': kwargs['signed_currency_fmt'],
'template_name': 'one',
'unsigned_currency_fmt': kwargs['unsigned_currency_fmt'],
}
@ -43,7 +44,7 @@ def test_template_parsing():
except IndexError as error:
assert False, error
assert "\n;Tag1: {value}\n" in tmpl_s
assert "\nIncome:Donations -100%\n" in tmpl_s
assert "\nIncome:Donations -{amount}\n" in tmpl_s
assert "\n;IncomeTag: Donations\n" in tmpl_s
@pytest.mark.parametrize('arg_s', [None, '-', 'output.ledger'])

View file

@ -72,3 +72,17 @@ def test_balancing():
" Income:Donations -0.50 USD",
" Income:Sales -0.51 USD",
]
def test_multivalue():
tmpl = template_from('Multivalue')
rendered = tmpl.render('DD', decimal.Decimal('150.00'), 'USD', DATE,
tax=decimal.Decimal('12.50'))
lines = [normalize_whitespace(s) for s in rendered.splitlines()]
assert lines == [
"",
"2015/03/14 DD",
" Expenses:Taxes 12.50 USD",
" Accrued:Accounts Receivable 137.50 USD",
" Income:RBI -15.00 USD",
" Income:Donations -135.00 USD",
]