enable API use with psycopg 3

[nominatim.git] / nominatim / typing.py

diff --git a/nominatim/typing.py b/nominatim/typing.py
index 308f3e6a2cbb515245e81aa47a739ce562b1c04e..bc4c5534777e537a3d0ffe1ab4a0c6d2b16f2456 100644 (file)
--- a/nominatim/typing.py
+++ b/nominatim/typing.py
@@ -2,7 +2,7 @@
 #
 # This file is part of Nominatim. (https://nominatim.org)
 #
-# Copyright (C) 2022 by the Nominatim developer community.
+# Copyright (C) 2023 by the Nominatim developer community.
 # For a full list of authors see the git log.
 """
 Type definitions for typing annotations.
@@ -11,7 +11,7 @@ Complex type definitions are moved here, to keep the source files readable.
 """
 from typing import Any, Union, Mapping, TypeVar, Sequence, TYPE_CHECKING
 
-# Generics varaible names do not confirm to naming styles, ignore globally here.
+# Generics variable names do not confirm to naming styles, ignore globally here.
 # pylint: disable=invalid-name,abstract-method,multiple-statements
 # pylint: disable=missing-class-docstring,useless-import-alias
 
@@ -50,3 +50,21 @@ else:
     Protocol = object
     Final = 'Final'
     TypedDict = dict
+
+
+# SQLAlchemy introduced generic types in version 2.0 making typing
+# incompatible with older versions. Add wrappers here so we don't have
+# to litter the code with bare-string types.
+
+if TYPE_CHECKING:
+    import sqlalchemy as sa
+    from typing_extensions import (TypeAlias as TypeAlias)
+else:
+    TypeAlias = str
+
+SaSelect: TypeAlias = 'sa.Select[Any]'
+SaRow: TypeAlias = 'sa.Row[Any]'
+SaColumn: TypeAlias = 'sa.ColumnElement[Any]'
+SaLabel: TypeAlias = 'sa.Label[Any]'
+SaFromClause: TypeAlias = 'sa.FromClause'
+SaSelectable: TypeAlias = 'sa.Selectable'