Refactor type hints for older Python version

Author: joonas-somero

hooks/catalog/catalog.py

@@ -1,4 +1,4 @@
-from typing import NamedTuple, Callable
+from typing import Optional, Callable
 
 from .ordering import OrderedValue
 from .apps import App, DocsApp, AppendixApp
@@ -65,7 +65,7 @@ def __get_sort_key(self, order_by: list[str]) -> Callable[[str], OrderedValue]:
     def __get_grouped_apps(self,
                            groups: list[str],
                            attr: str,
-                           callback: Callable[[App, str], bool] | None=None) -> dict:
+                           callback: Optional[Callable[[App, str], bool]]=None) -> dict:
         callback_fn = (callback if callback is not None
                        else lambda app, attr, value: (value in getattr(app, attr)
                                                       if hasattr(app, attr)

hooks/catalog/export.py

@@ -1,5 +1,6 @@
 import json
 from pathlib import Path
+from typing import Union
 
 import humps
 
@@ -177,7 +178,7 @@ def append_by_system(self, markdown):
 
     # 'def export_by_license(self)' not needed.
 
-    def append_content(self, filepath: Path, markdown) -> str | None:
+    def append_content(self, filepath: Path, markdown) -> Union[str, None]:
         attr_name = f"append_{filepath.stem}"
 
         if hasattr(self, attr_name):