Update deprecated type annotations produced by AWS scaffold tool

purcell · purcell · commit df9a078bef35 · 2025-11-07T10:05:57.000Z
As of Python 3.9, common type annotations have changed, and the old
ones (e.g. List, Optional, Union) generate deprecation warnings in
some tools (pyright in my case).

This change updates the generation of scaffolded types to use the new
names, and also adds default values in some cases, where further
warnings were previously reported.
diff --git a/localstack-core/localstack/aws/scaffold.py b/localstack-core/localstack/aws/scaffold.py
@@ -188,9 +188,7 @@ def _print_as_class(self, output, base: str, doc=True, quote_types=False):
             if member in self.shape.required_members:
                 output.write(f"    {member}: IO[{q}{to_valid_python_name(shape.name)}{q}]\n")
             else:
-                output.write(
-                    f"    {member}: Optional[IO[{q}{to_valid_python_name(shape.name)}{q}]]\n"
-                )
+                output.write(f"    {member}: {q}IO[{to_valid_python_name(shape.name)}] | None{q}\n")
             del remaining_members[member]
         # render the streaming payload first
         if self.is_response and self.response_operation.has_streaming_output:
@@ -199,25 +197,26 @@ def _print_as_class(self, output, base: str, doc=True, quote_types=False):
             shape_name = to_valid_python_name(shape.name)
             if member in self.shape.required_members:
                 output.write(
-                    f"    {member}: Union[{q}{shape_name}{q}, IO[{q}{shape_name}{q}], Iterable[{q}{shape_name}{q}]]\n"
+                    f"    {member}: {q}{shape_name} | IO[{shape_name}] | Iterable[{shape_name}]{q}\n"
                 )
             else:
                 output.write(
-                    f"    {member}: Optional[Union[{q}{shape_name}{q}, IO[{q}{shape_name}{q}], Iterable[{q}{shape_name}{q}]]]\n"
+                    f"    {member}: {q}{shape_name} | IO[{shape_name}] | Iterable[{shape_name}] | None{q}\n"
                 )
             del remaining_members[member]
 
         for k, v in remaining_members.items():
+            shape_name = to_valid_python_name(v.name)
             if k in self.shape.required_members:
                 if v.serialization.get("eventstream"):
-                    output.write(f"    {k}: Iterator[{q}{to_valid_python_name(v.name)}{q}]\n")
+                    output.write(f"    {k}: Iterator[{q}{shape_name}{q}]\n")
                 else:
-                    output.write(f"    {k}: {q}{to_valid_python_name(v.name)}{q}\n")
+                    output.write(f"    {k}: {q}{shape_name}{q}\n")
             else:
                 if v.serialization.get("eventstream"):
-                    output.write(f"    {k}: Iterator[{q}{to_valid_python_name(v.name)}{q}]\n")
+                    output.write(f"    {k}: Iterator[{q}{shape_name}{q}]\n")
                 else:
-                    output.write(f"    {k}: Optional[{q}{to_valid_python_name(v.name)}{q}]\n")
+                    output.write(f"    {k}: {q}{shape_name} | None{q}\n")
 
     def _print_as_typed_dict(self, output, doc=True, quote_types=False):
         name = to_valid_python_name(self.shape.name)
@@ -236,7 +235,7 @@ def _print_as_typed_dict(self, output, doc=True, quote_types=False):
                 if v.serialization.get("eventstream"):
                     output.write(f'    "{k}": Iterator[{q}{member_name}{q}],\n')
                 else:
-                    output.write(f'    "{k}": Optional[{q}{member_name}{q}],\n')
+                    output.write(f'    "{k}": {q}{member_name} | None{q},\n')
         output.write("}, total=False)")
 
     def print_shape_doc(self, output, shape):
@@ -256,11 +255,11 @@ def print_declaration(self, output, doc=True, quote_types=False):
             self._print_structure_declaration(output, doc, quote_types)
         elif isinstance(shape, ListShape):
             output.write(
-                f"{to_valid_python_name(shape.name)} = List[{q}{to_valid_python_name(shape.member.name)}{q}]"
+                f"{to_valid_python_name(shape.name)} = list[{q}{to_valid_python_name(shape.member.name)}{q}]"
             )
         elif isinstance(shape, MapShape):
             output.write(
-                f"{to_valid_python_name(shape.name)} = Dict[{q}{to_valid_python_name(shape.key.name)}{q}, {q}{to_valid_python_name(shape.value.name)}{q}]"
+                f"{to_valid_python_name(shape.name)} = dict[{q}{to_valid_python_name(shape.key.name)}{q}, {q}{to_valid_python_name(shape.value.name)}{q}]"
             )
         elif isinstance(shape, StringShape):
             if shape.enum:
@@ -316,9 +315,8 @@ def get_order(self):
 def generate_service_types(output, service: ServiceModel, doc=True):
     output.write("from datetime import datetime\n")
     output.write("from enum import StrEnum\n")
-    output.write(
-        "from typing import Dict, List, Optional, Iterator, Iterable, IO, Union, TypedDict\n"
-    )
+    output.write("from typing import IO, TypedDict\n")
+    output.write("from collections.abc import Iterable, Iterator\n")
     output.write("\n")
     output.write(
         "from localstack.aws.api import handler, RequestContext, ServiceException, ServiceRequest"
@@ -372,8 +370,8 @@ def generate_service_api(output, service: ServiceModel, doc=True):
 
     output.write(f"class {class_name}:\n")
     output.write("\n")
-    output.write(f'    service = "{service.service_name}"\n')
-    output.write(f'    version = "{service.api_version}"\n')
+    output.write(f'    service: str = "{service.service_name}"\n')
+    output.write(f'    version: str = "{service.api_version}"\n')
     for op_name in service.operation_names:
         operation: OperationModel = service.operation_model(op_name)
 
