balance_sheet: Default classification sort by root account.

This provides more consistent presentation across sheets,
especially the financial position+cash flows.

conservancy_beancount/reports/balance_sheet.py

@@ -51,6 +51,7 @@ from .. import config as configmod
 from .. import data
 from .. import ranges
 
+EQUITY_ACCOUNTS = frozenset(['Equity', 'Income', 'Expenses'])
 PROGNAME = 'balance-sheet-report'
 logger = logging.getLogger('conservancy_beancount.tools.balance_sheet')
 
@@ -156,8 +157,13 @@ class Balances:
 
     def classifications(self,
                         account: str,
-                        sort_period: int=Period.PERIOD,
+                        sort_period: Optional[int]=None,
     ) -> Sequence[data.Account]:
+        if sort_period is None:
+            if account in EQUITY_ACCOUNTS:
+                sort_period = Period.PERIOD
+            else:
+                sort_period = Period.ANY
         class_bals: Mapping[data.Account, core.MutableBalance] \
             = collections.defaultdict(core.MutableBalance)
         for key, balance in self.balances.items():
@@ -183,7 +189,6 @@ class Balances:
 class Report(core.BaseODS[Sequence[None], None]):
     C_CASH = 'Cash'
     C_SATISFIED = 'Satisfaction of program restrictions'
-    EQUITY_ACCOUNTS = frozenset(['Equity', 'Income', 'Expenses'])
     NO_BALANCE = core.Balance()
     SPACE = ' ' * 4
 
@@ -238,7 +243,7 @@ class Report(core.BaseODS[Sequence[None], None]):
     def walk_classifications_by_account(
             self,
             account: str,
-            sort_period: int=Period.PERIOD,
+            sort_period: Optional[int]=None,
     ) -> Iterator[Tuple[str, Optional[data.Account]]]:
         return self.walk_classifications(self.balances.classifications(
             account, sort_period,
@@ -266,7 +271,7 @@ class Report(core.BaseODS[Sequence[None], None]):
         period_assets = core.MutableBalance()
         self.add_row(self.string_cell("Assets", stylename=self.style_bold))
         self.add_row()
-        for text, classification in self.walk_classifications_by_account('Assets', Period.ANY):
+        for text, classification in self.walk_classifications_by_account('Assets'):
             text_cell = self.string_cell(text)
             if classification is None:
                 self.add_row(text_cell)
@@ -298,7 +303,7 @@ class Report(core.BaseODS[Sequence[None], None]):
         self.add_row()
         self.add_row(self.string_cell("Liabilities", stylename=self.style_bold))
         self.add_row()
-        for text, classification in self.walk_classifications_by_account('Liabilities', Period.ANY):
+        for text, classification in self.walk_classifications_by_account('Liabilities'):
             text_cell = self.string_cell(text)
             if classification is None:
                 self.add_row(text_cell)
@@ -330,11 +335,11 @@ class Report(core.BaseODS[Sequence[None], None]):
             preposition = "Without" if fund is Fund.UNRESTRICTED else "With"
             period_bal = -sum(
                 (self.balances.total(account=account, fund=fund)
-                 for account in self.EQUITY_ACCOUNTS), core.MutableBalance(),
+                 for account in EQUITY_ACCOUNTS), core.MutableBalance(),
             )
             prior_bal = period_bal + sum(
                 (self.balances.total(account=account, fund=fund, period=Period.PERIOD)
-                 for account in self.EQUITY_ACCOUNTS), core.MutableBalance(),
+                 for account in EQUITY_ACCOUNTS), core.MutableBalance(),
             )
             self.add_row(
                 self.string_cell(f"{preposition} donor restrictions"),
@@ -497,7 +502,7 @@ class Report(core.BaseODS[Sequence[None], None]):
                 kwargs['period'] = Period.OPENING
         beginnings = [
             -sum((self.balances.total(account=account, **kwargs)
-                  for account in self.EQUITY_ACCOUNTS), core.MutableBalance())
+                  for account in EQUITY_ACCOUNTS), core.MutableBalance())
             for kwargs in bal_kwargs
         ]
         self.add_row()
@@ -608,7 +613,7 @@ class Report(core.BaseODS[Sequence[None], None]):
 
         totals = [
             -sum((self.balances.total(account=account, **kwargs)
-                  for account in self.EQUITY_ACCOUNTS), core.MutableBalance())
+                  for account in EQUITY_ACCOUNTS), core.MutableBalance())
             for kwargs in bal_kwargs
         ]
         self.add_row(