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src/nominatim_db/typing.py

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+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2024 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 Any, Union, Mapping, TypeVar, Sequence, TYPE_CHECKING
+
+# 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
+
+if TYPE_CHECKING:
+    import psycopg2.sql
+    import psycopg2.extensions
+    import psycopg2.extras
+    import os
+
+StrPath = Union[str, 'os.PathLike[str]']
+
+SysEnv = Mapping[str, str]
+
+# psycopg2-related types
+
+Query = Union[str, bytes, 'psycopg2.sql.Composable']
+
+T_ResultKey = TypeVar('T_ResultKey', int, str)
+
+class DictCursorResult(Mapping[str, Any]):
+    def __getitem__(self, x: Union[int, str]) -> Any: ...
+
+DictCursorResults = Sequence[DictCursorResult]
+
+T_cursor = TypeVar('T_cursor', bound='psycopg2.extensions.cursor')
+
+# The following typing features require typing_extensions to work
+# on all supported Python versions.
+# Only require this for type checking but not for normal operations.
+
+if TYPE_CHECKING:
+    from typing_extensions import (Protocol as Protocol,
+                                   Final as Final,
+                                   TypedDict as TypedDict)
+else:
+    Protocol = object
+    Final = 'Final'
+    TypedDict = dict