template: Don't output accounts that end up having no amount.

import2ledger/template.py

@@ -91,12 +91,16 @@ class AccountSplitter:
     def __init__(self, signed_currencies, signed_currency_fmt, unsigned_currency_fmt,
                  template_name):
         self.splits = collections.OrderedDict()
+        self.metadata = []
         self.signed_currency_fmt = signed_currency_fmt
         self.unsigned_currency_fmt = unsigned_currency_fmt
         self.signed_currencies = set(signed_currencies)
         self.template_name = template_name
         self._last_template_vars = object()
 
+    def is_empty(self):
+        return not self.splits
+
     def add(self, account, amount_expr):
         try:
             clean_expr = AmountTokenTransformer.from_str(amount_expr).transform()
@@ -105,6 +109,10 @@ class AccountSplitter:
             raise errors.UserInputConfigurationError(error.args[0], amount_expr)
         else:
             self.splits[account] = compiled_expr
+            self.metadata.append('')
+
+    def set_metadata(self, metadata_s):
+        self.metadata[-1] = metadata_s
 
     def _currency_decimal(self, amount, currency):
         return decimal.Decimal(babel.numbers.format_currency(amount, currency, '###0.###'))
@@ -146,11 +154,16 @@ class AccountSplitter:
             amt_fmt = self.signed_currency_fmt
         else:
             amt_fmt = self.unsigned_currency_fmt
-        for account, amount in amounts.items():
-            yield '    {:45}  {:>19}\n'.format(
-                account.format_map(template_vars),
-                babel.numbers.format_currency(amount, template_vars['currency'], amt_fmt),
-            )
+        for (account, amount), metadata in zip(amounts.items(), self.metadata):
+            if amount == 0:
+                yield ''
+            else:
+                account_s = '    {:45}  {:>19}\n'.format(
+                    account.format_map(template_vars),
+                    babel.numbers.format_currency(amount, template_vars['currency'], amt_fmt),
+                )
+                metadata_s = metadata.format_map(template_vars)
+                yield account_s + metadata_s
 
     def render_next(self, template_vars):
         if template_vars is not self._last_template_vars:
@@ -180,8 +193,7 @@ class Template:
                 break
         del lines[:index]
         self.format_funcs = [
-            '\n'.format_map,
-            '{date} {payee}\n'.format_map,
+            '\n{date} {payee}\n'.format_map,
         ]
         start_index = 0
         for index, line in enumerate(lines):
@@ -204,7 +216,10 @@ class Template:
 
     def _add_str_func(self, str_seq):
         str_flat = ''.join('      ' + s for s in str_seq)
-        self.format_funcs.append(str_flat.format_map)
+        if self.splitter.is_empty():
+            self.format_funcs.append(str_flat.format_map)
+        else:
+            self.splitter.set_metadata(str_flat)
 
     def render(self, payee, amount, currency, date=None, **template_vars):
         if date is None:

tests/data/templates.ini

@@ -24,6 +24,7 @@ template =
 [Multivalue]
 template =
  Expenses:Taxes  {tax}
+ ;TaxAuthority: IRS
  Accrued:Accounts Receivable  {amount} - {tax}
  Income:RBI         -.1*{amount}
  Income:Donations   -.9*{amount}

tests/test_templates.py

@@ -83,11 +83,25 @@ def test_multivalue():
         "",
         "2015/03/14 DD",
         "  Expenses:Taxes  12.50 USD",
+        "  ;TaxAuthority: IRS",
         "  Accrued:Accounts Receivable  137.50 USD",
         "  Income:RBI  -15.00 USD",
         "  Income:Donations  -135.00 USD",
     ]
 
+def test_zeroed_account_skipped():
+    tmpl = template_from('Multivalue')
+    rendered = tmpl.render('GG', decimal.Decimal('110.00'), 'USD', DATE,
+                           tax=decimal.Decimal(0))
+    lines = [normalize_whitespace(s) for s in rendered.splitlines()]
+    assert lines == [
+        "",
+        "2015/03/14 GG",
+        "  Accrued:Accounts Receivable  110.00 USD",
+        "  Income:RBI  -11.00 USD",
+        "  Income:Donations  -99.00 USD",
+    ]
+
 @pytest.mark.parametrize('amount_expr', [
     '',
     'name',