balance_sheet: Transform "chart of accounts" into trial balances.

It was mostly this already, just needed to add a column and change the
title.

conservancy_beancount/reports/balance_sheet.py

@@ -242,7 +242,7 @@ class Report(core.BaseODS[Sequence[None], None]):
         self.write_activities()
         self.write_functional_expenses()
         self.write_cash_flows()
-        self.write_chart_of_accounts()
+        self.write_trial_balances()
 
     def walk_classifications(self, cseq: Iterable[data.Account]) \
         -> Iterator[Tuple[str, Optional[data.Account]]]:
@@ -565,12 +565,14 @@ class Report(core.BaseODS[Sequence[None], None]):
             stylename=self.style_bottomline,
         )
 
-    def write_chart_of_accounts(self) -> None:
+    def write_trial_balances(self) -> None:
         self.start_sheet(
-            "Chart of Accounts",
-            ["Account Name"], ["Classification"],
+            "Trial Balances",
+            ["Account Name"],
+            ["Classification"],
+            ["Balance Ending", self.opening_name],
             totals_prefix=["Change During", "Year Ending"],
-            title_fmt="{sheet_name}",
+            title_fmt="Chart of Accounts with DRAFT {sheet_name}",
         )
         # Widen text columns
         col_style = self.column_style(3.5)
@@ -579,10 +581,10 @@ class Report(core.BaseODS[Sequence[None], None]):
         # Patch up header row text
         header_row = self.sheet.lastChild
         header_row.removeChild(header_row.firstChild)
-        header_row.addElement(self.multiline_cell(
+        header_row.insertBefore(self.multiline_cell(
             ["Balance Ending", self.period_name],
             stylename=header_row.lastChild.getAttribute('stylename'),
-        ))
+        ), header_row.lastChild)
 
         for acct_root in ['Assets', 'Liabilities', 'Income', 'Expenses', 'Equity']:
             norm_func = core.normalize_amount_func(f'{acct_root}:Dummy')
@@ -592,16 +594,19 @@ class Report(core.BaseODS[Sequence[None], None]):
                 period_bal = self.balances.total(account=account, period=Period.PERIOD)
                 prior_bal = self.balances.total(account=account, period=Period.PRIOR)
                 if want_balance:
-                    total_bal = self.balances.total(account=account)
-                    total_cell = self.balance_cell(norm_func(total_bal))
+                    close_bal = self.balances.total(account=account)
+                    close_cell = self.balance_cell(norm_func(close_bal))
+                    open_cell = self.balance_cell(norm_func(close_bal - period_bal))
                 else:
-                    total_cell = odf.table.TableCell()
+                    close_cell = odf.table.TableCell()
+                    open_cell = odf.table.TableCell()
                 self.add_row(
                     self.string_cell(account),
                     self.string_cell(account.meta.get('classification', '')),
+                    open_cell,
                     self.balance_cell(norm_func(period_bal)),
+                    close_cell,
                     self.balance_cell(norm_func(prior_bal)),
-                    total_cell,
                 )
 
 

setup.py

@@ -5,7 +5,7 @@ from setuptools import setup
 setup(
     name='conservancy_beancount',
     description="Plugin, library, and reports for reading Conservancy's books",
-    version='1.8.1',
+    version='1.8.2',
     author='Software Freedom Conservancy',
     author_email='info@sfconservancy.org',
     license='GNU AGPLv3+',