typing: Annotate Iterators more specifically.

conservancy_beancount/data.py

@@ -293,13 +293,13 @@ class Posting(BasePosting):
         )
 
     @classmethod
-    def from_txn(cls, txn: Transaction) -> Iterable['Posting']:
+    def from_txn(cls, txn: Transaction) -> Iterator['Posting']:
         """Yield an enhanced Posting object for every posting in the transaction"""
         for index, post in enumerate(txn.postings):
             yield cls.from_beancount(txn, index, post)
 
     @classmethod
-    def from_entries(cls, entries: Iterable[Directive]) -> Iterable['Posting']:
+    def from_entries(cls, entries: Iterable[Directive]) -> Iterator['Posting']:
         """Yield an enhanced Posting object for every posting in these entries"""
         for entry in entries:
             # Because Beancount's own Transaction class isn't type-checkable,

conservancy_beancount/plugin/__init__.py

@@ -22,7 +22,7 @@ from typing import (
     AbstractSet,
     Any,
     Dict,
-    Iterable,
+    Iterator,
     List,
     Optional,
     Set,
@@ -93,7 +93,7 @@ class HookRegistry:
         for mod_name, hook_names in self.INCLUDED_HOOKS.items():
             self.import_hooks(mod_name, *(hook_names or []), package=self.__module__)
 
-    def group_by_directive(self, config_str: str='') -> Iterable[Tuple[HookName, Type[Hook]]]:
+    def group_by_directive(self, config_str: str='') -> Iterator[Tuple[HookName, Type[Hook]]]:
         config_str = config_str.strip()
         if not config_str:
             config_str = 'all'

conservancy_beancount/plugin/core.py

@@ -259,7 +259,7 @@ class _RequireLinksPostingMetadataHook(_PostingHook):
                         txn: Transaction,
                         post: data.Posting,
                         keys: Sequence[MetaKey],
-    ) -> Iterable[errormod.InvalidMetadataError]:
+    ) -> Iterator[errormod.InvalidMetadataError]:
         have_docs = False
         for key in keys:
             try:

conservancy_beancount/reports/core.py

@@ -143,7 +143,7 @@ class RelatedPostings(Sequence[data.Posting]):
     def clear(self) -> None:
         self._postings.clear()
 
-    def iter_with_balance(self) -> Iterable[Tuple[data.Posting, Balance]]:
+    def iter_with_balance(self) -> Iterator[Tuple[data.Posting, Balance]]:
         balance = MutableBalance()
         for post in self:
             balance.add_amount(post.units)