add lazy model generation

codegen-output-py/types/.smithy-python-manifest.json

@@ -1,6 +1,8 @@
 {
   "files": {
-    "src/example_types/_private/schemas.py": "d0f35e8979c4aa9d49a1d9c0c8efeb860420bc0ceab3ba3edcc9488c053e9110"
+    "src/example_types/_private/schemas.py": "d0f35e8979c4aa9d49a1d9c0c8efeb860420bc0ceab3ba3edcc9488c053e9110",
+    "src/example_types/models.py": "6042e2e6454b40fef929d96cb7608ae8c591ac7205577f14337435718bb7c077",
+    "src/example_types/models.pyi": "bb3d59e91999a62438fce52fe3be551c63f998565e4f9640e4fb1e275b972b14"
   },
   "version": 1
 }

codegen-output-py/types/src/example_types/models.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+from smithy_core._dynamic_models import ModelRegistry
+from smithy_core.exceptions import ModeledError
+
+from ._private import schemas
+
+
+class ServiceError(ModeledError):
+    """
+    Base error for all errors in the service.
+
+    Some exceptions do not extend from this class, including synthetic,
+    implicit, and shared exception types.
+    """
+
+
+_MODEL_INDEX = {
+    "GetExampleInput": "GET_EXAMPLE_INPUT",
+    "GetExampleOutput": "GET_EXAMPLE_OUTPUT",
+    "ExampleError": "EXAMPLE_ERROR",
+    "RenamedExample": "RENAMED_EXAMPLE",
+    "ExampleValue": "EXAMPLE_VALUE",
+    "ExampleValueText": "EXAMPLE_VALUE",
+    "ExampleValueNumber": "EXAMPLE_VALUE",
+    "ExampleValueEmpty": "EXAMPLE_VALUE",
+    "ExampleValueUnknown": "EXAMPLE_VALUE",
+    "Status": "STATUS",
+    "Code": "CODE",
+}
+
+_RENAMES = {
+    "RenamedExample": "RENAMED_EXAMPLE",
+    "ExampleValue": "EXAMPLE_VALUE",
+}
+
+_TARGET_NAMES = {
+    "example#Example": "RenamedExample",
+    "example#Value": "ExampleValue",
+}
+
+_MODEL_NAMES = (*tuple(_MODEL_INDEX), "Unit")
+__all__ = ("ServiceError", *_MODEL_NAMES)
+
+
+_registry = ModelRegistry(
+    schemas,
+    renames=_RENAMES,
+    index=_MODEL_INDEX,
+    target_names=_TARGET_NAMES,
+    shape_names=frozenset(
+        {
+            "Code",
+            "ExampleError",
+            "ExampleValue",
+            "GetExampleInput",
+            "GetExampleOutput",
+            "RenamedExample",
+            "Status",
+            "Unit",
+        }
+    ),
+    service_error="ServiceError",
+)
+del schemas, ModelRegistry, ModeledError
+
+
+def __getattr__(name: str):
+    value = _registry.build(name)
+    globals()[name] = value
+    return value
+
+
+def __dir__() -> list[str]:
+    return sorted({*globals(), *__all__})

codegen-output-py/types/src/example_types/models.pyi

@@ -0,0 +1,135 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from enum import IntEnum, StrEnum
+from typing import Self
+
+from smithy_core.deserializers import ShapeDeserializer
+from smithy_core.documents import Document
+from smithy_core.exceptions import ModeledError
+from smithy_core.response import ResponseMetadata
+from smithy_core.serializers import ShapeSerializer
+from smithy_core.types import UnknownEnumMixin
+
+__all__ = [
+    "Code",
+    "ExampleError",
+    "ExampleValue",
+    "ExampleValueEmpty",
+    "ExampleValueNumber",
+    "ExampleValueText",
+    "ExampleValueUnknown",
+    "GetExampleInput",
+    "GetExampleOutput",
+    "RenamedExample",
+    "ServiceError",
+    "Status",
+    "Unit",
+]
+
+class _SerdeShape:
+    def serialize(self, serializer: ShapeSerializer) -> None: ...
+    def serialize_members(self, serializer: ShapeSerializer) -> None: ...
+    @classmethod
+    def deserialize(cls, deserializer: ShapeDeserializer) -> Self: ...
+
+class ServiceError(ModeledError):
+    """
+    Base error for all errors in the service.
+
+    Some exceptions do not extend from this class, including synthetic,
+    implicit, and shared exception types.
+    """
+
+@dataclass(kw_only=True)
+class GetExampleInput(_SerdeShape):
+    "Input for retrieving an example."
+
+    id: str | None = ...
+
+@dataclass(kw_only=True)
+class GetExampleOutput(_SerdeShape):
+    "Dataclass for GetExampleOutput structure."
+
+    example: RenamedExample | None = ...
+    value: ExampleValue | None = ...
+    response_metadata: ResponseMetadata = ...
+    """
+    Metadata about the response that produced this output.
+
+    Use this to recover the request identifiers a service's support team
+    needs in order to investigate a call. Members of the metadata are
+    individually optional.
+    """
+
+@dataclass(kw_only=True)
+class ExampleError(ServiceError, _SerdeShape):
+    "An example modeled error."
+
+    retry_after_seconds: int | None = ...
+    response_metadata: ResponseMetadata = ...
+    """
+    Metadata about the response that produced this output.
+
+    Use this to recover the request identifiers a service's support team
+    needs in order to investigate a call. Members of the metadata are
+    individually optional.
+    """
+
+@dataclass(kw_only=True)
+class RenamedExample(_SerdeShape):
+    "A representative generated structure."
+
+    name: str
+    "The example name."
+    count: int | None = ...
+    tags: list[str] | None = ...
+    attributes: dict[str, Document] | None = ...
+    choice: ExampleValue | None = ...
+    status: str | None = ...
+    code: int | None = ...
+
+@dataclass
+class ExampleValueText(_SerdeShape):
+    value: str
+
+@dataclass
+class ExampleValueNumber(_SerdeShape):
+    value: int
+
+@dataclass
+class ExampleValueEmpty(_SerdeShape):
+    value: Unit
+
+@dataclass
+class ExampleValueUnknown(_SerdeShape):
+    """
+    Represents an unknown variant.
+
+    If you receive this value, you will need to update your library to
+    receive the parsed value.
+
+    This value may not be deliberately sent.
+    """
+
+    tag: str
+
+ExampleValue = (
+    ExampleValueText | ExampleValueNumber | ExampleValueEmpty | ExampleValueUnknown
+)
+"A representative generated union."
+
+class _ExampleValueDeserializer:
+    def deserialize(self, deserializer: ShapeDeserializer) -> ExampleValue: ...
+
+class Status(UnknownEnumMixin, StrEnum):
+    ACTIVE = "active"
+    INACTIVE = "inactive"
+
+class Code(UnknownEnumMixin, IntEnum):
+    OK = 200
+    NOT_FOUND = 404
+
+@dataclass(kw_only=True)
+class Unit(_SerdeShape):
+    pass

codegen/core/src/main/java/software/amazon/smithy/python/codegen/PythonSymbolProvider.java

@@ -147,6 +147,9 @@ public String toMemberName(MemberShape shape) {
         }
 
         var memberName = escaper.escapeMemberName(CaseUtils.toSnakeCase(shape.getMemberName()));
+        if (memberName.startsWith("__") && !memberName.endsWith("__")) {
+            memberName += "___";
+        }
 
         // Escape words that are only reserved for error members.
         if (shape.hasTrait(ErrorTrait.class)) {
@@ -170,6 +173,16 @@ && carriesResponseMetadata(container)) {
         }
 
         if (container.isEnumShape() || container.isIntEnumShape()) {
+            if (memberName.startsWith("__")
+                    && memberName.endsWith("__")
+                    && !memberName.endsWith("___")) {
+                memberName += "_";
+            } else if (memberName.startsWith("_")
+                    && !memberName.startsWith("__")
+                    && memberName.endsWith("_")
+                    && !memberName.endsWith("__")) {
+                memberName += "_";
+            }
             memberName = memberName.toUpperCase(Locale.ENGLISH);
         }
         return memberName;

codegen/core/src/main/resources/software/amazon/smithy/python/codegen/reserved-member-names.txt

@@ -81,3 +81,17 @@ str
 # that are likely imported in the generated code (e.g. datetime)
 # We only escape the types we use.
 datetime
+
+# Generated model runtime methods.
+serialize
+serialize_members
+deserialize
+
+# Dataclass-generated methods and hooks.
+__init__
+__post_init__
+__repr__
+__annotations__
+
+# Generated model runtime methods.
+_smithy_default

codegen/core/src/test/java/software/amazon/smithy/python/codegen/PythonSymbolProviderTest.java

@@ -137,6 +137,68 @@ public void testUnrelatedMembersOnOutputsAndErrorsAreUnaffected() {
         assertEquals("retry_after", memberName(provider, model, "ThingError$retryAfter"));
     }
 
+    @Test
+    public void testDataclassHooksAreEscaped() {
+        Model model = loadModel("""
+                $version: "2"
+                namespace smithy.example
+
+                service TestService {
+                    version: "2024-01-01"
+                    operations: [GetThing]
+                }
+
+                operation GetThing {
+                    input: GetThingInput
+                }
+
+                structure GetThingInput {
+                    __init__: String
+                    __post_init__: String
+                    _smithy_default: String
+                    __repr__: String
+                    __annotations__: String
+                    __value: String
+                }
+                """);
+        PythonSymbolProvider provider = createProvider(model);
+
+        assertEquals("__init___", memberName(provider, model, "GetThingInput$__init__"));
+        assertEquals("__post_init___", memberName(provider, model, "GetThingInput$__post_init__"));
+        assertEquals("_smithy_default_", memberName(provider, model, "GetThingInput$_smithy_default"));
+        assertEquals("__repr___", memberName(provider, model, "GetThingInput$__repr__"));
+        assertEquals("__annotations___", memberName(provider, model, "GetThingInput$__annotations__"));
+        assertEquals("__value___", memberName(provider, model, "GetThingInput$__value"));
+    }
+
+    @Test
+    public void testEnumSunderNamesAreEscaped() {
+        Model model = loadModel("""
+                $version: "2"
+                namespace smithy.example
+
+                service TestService {
+                    version: "2024-01-01"
+                }
+
+                enum StringValues {
+                    _VALUE_ = "value"
+                    __DUNDER__ = "dunder"
+                }
+
+                intEnum IntValues {
+                    _VALUE_ = 1
+                    __DUNDER__ = 2
+                }
+                """);
+        PythonSymbolProvider provider = createProvider(model);
+
+        assertEquals("_VALUE__", memberName(provider, model, "StringValues$_VALUE_"));
+        assertEquals("_VALUE__", memberName(provider, model, "IntValues$_VALUE_"));
+        assertEquals("__DUNDER___", memberName(provider, model, "StringValues$__DUNDER__"));
+        assertEquals("__DUNDER___", memberName(provider, model, "IntValues$__DUNDER__"));
+    }
+
     private static final String RESPONSE_METADATA_MODEL = """
             $version: "2"
             namespace smithy.example

packages/smithy-core/.changes/next-release/smithy-core-enhancement-model-target-names.json

@@ -0,0 +1,4 @@
+{
+  "type": "enhancement",
+  "description": "Added optional full shape ID target mappings to `ModelRegistry` so generators can resolve renamed and same-named cross-namespace model targets without ambiguous local-name lookups."
+}