move complex typing annotations to extra file

nominatim/typing.py

@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
+"""
+Type definitions for typing annotations.
+
+Complex type definitions are moved here, to keep the source files readable.
+"""
+from typing import Union, TypeVar, TYPE_CHECKING
+
+# Generics varaible names do not confirm to naming styles, ignore globally here.
+# pylint: disable=invalid-name
+
+if TYPE_CHECKING:
+    import psycopg2.sql
+    import psycopg2.extensions
+    import os
+
+StrPath = Union[str, 'os.PathLike[str]']
+
+# psycopg2-related types
+
+Query = Union[str, bytes, 'psycopg2.sql.Composable']
+T_cursor = TypeVar('T_cursor', bound='psycopg2.extensions.cursor')