Skip from __future__ import annotations for Python 3.14+ targets (PEP 649) (#2658)

* Skip future annotations import for Python 3.14 and add version checks for native deferred annotations

* Skip future annotations for Python 3.13 and 3.14 in tests with version checks

Author: koxudaxi

src/datamodel_code_generator/format.py

@@ -75,6 +75,16 @@ def _is_py_311_or_later(self) -> bool:  # pragma: no cover
     def _is_py_312_or_later(self) -> bool:  # pragma: no cover
         return self.value not in {self.PY_39.value, self.PY_310.value, self.PY_311.value}
 
+    @cached_property
+    def _is_py_314_or_later(self) -> bool:
+        return self.value not in {
+            self.PY_39.value,
+            self.PY_310.value,
+            self.PY_311.value,
+            self.PY_312.value,
+            self.PY_313.value,
+        }
+
     @property
     def has_union_operator(self) -> bool:  # pragma: no cover
         """Check if Python version supports the union operator (|)."""
@@ -100,6 +110,11 @@ def has_type_statement(self) -> bool:
         """Check if Python version supports type statements."""
         return self._is_py_312_or_later
 
+    @property
+    def has_native_deferred_annotations(self) -> bool:
+        """Check if Python version has native deferred annotations (Python 3.14+)."""
+        return self._is_py_314_or_later
+
     @property
     def has_strenum(self) -> bool:
         """Check if Python version supports StrEnum."""

src/datamodel_code_generator/parser/base.py

@@ -2146,7 +2146,11 @@ def parse(  # noqa: PLR0912, PLR0913, PLR0914, PLR0915, PLR0917
         """Parse schema and generate code, returning single file or module dict."""
         self.parse_raw()
 
-        if with_import and not disable_future_imports:
+        if (
+            with_import
+            and not disable_future_imports
+            and not self.target_python_version.has_native_deferred_annotations
+        ):
             self.imports.append(IMPORT_ANNOTATIONS)
 
         if format_:

tests/data/expected/main/openapi/target_python_version_313_has_future_annotations.py

@@ -0,0 +1,69 @@
+# generated by datamodel-codegen:
+#   filename:  api.yaml
+#   timestamp: 1985-10-26T08:21:00+00:00
+
+from __future__ import annotations
+
+from typing import List, Optional
+
+from pydantic import AnyUrl, BaseModel, Field
+
+
+class Pet(BaseModel):
+    id: int
+    name: str
+    tag: Optional[str] = None
+
+
+class Pets(BaseModel):
+    __root__: List[Pet]
+
+
+class User(BaseModel):
+    id: int
+    name: str
+    tag: Optional[str] = None
+
+
+class Users(BaseModel):
+    __root__: List[User]
+
+
+class Id(BaseModel):
+    __root__: str
+
+
+class Rules(BaseModel):
+    __root__: List[str]
+
+
+class Error(BaseModel):
+    code: int
+    message: str
+
+
+class Api(BaseModel):
+    apiKey: Optional[str] = Field(
+        None, description='To be used as a dataset parameter value'
+    )
+    apiVersionNumber: Optional[str] = Field(
+        None, description='To be used as a version parameter value'
+    )
+    apiUrl: Optional[AnyUrl] = Field(
+        None, description="The URL describing the dataset's fields"
+    )
+    apiDocumentationUrl: Optional[AnyUrl] = Field(
+        None, description='A URL to the API console for each API'
+    )
+
+
+class Apis(BaseModel):
+    __root__: List[Api]
+
+
+class Event(BaseModel):
+    name: Optional[str] = None
+
+
+class Result(BaseModel):
+    event: Optional[Event] = None

tests/data/expected/main/openapi/target_python_version_314_no_future_annotations.py

@@ -0,0 +1,67 @@
+# generated by datamodel-codegen:
+#   filename:  api.yaml
+#   timestamp: 1985-10-26T08:21:00+00:00
+
+from typing import List, Optional
+
+from pydantic import AnyUrl, BaseModel, Field
+
+
+class Pet(BaseModel):
+    id: int
+    name: str
+    tag: Optional[str] = None
+
+
+class Pets(BaseModel):
+    __root__: List[Pet]
+
+
+class User(BaseModel):
+    id: int
+    name: str
+    tag: Optional[str] = None
+
+
+class Users(BaseModel):
+    __root__: List[User]
+
+
+class Id(BaseModel):
+    __root__: str
+
+
+class Rules(BaseModel):
+    __root__: List[str]
+
+
+class Error(BaseModel):
+    code: int
+    message: str
+
+
+class Api(BaseModel):
+    apiKey: Optional[str] = Field(
+        None, description='To be used as a dataset parameter value'
+    )
+    apiVersionNumber: Optional[str] = Field(
+        None, description='To be used as a version parameter value'
+    )
+    apiUrl: Optional[AnyUrl] = Field(
+        None, description="The URL describing the dataset's fields"
+    )
+    apiDocumentationUrl: Optional[AnyUrl] = Field(
+        None, description='A URL to the API console for each API'
+    )
+
+
+class Apis(BaseModel):
+    __root__: List[Api]
+
+
+class Event(BaseModel):
+    name: Optional[str] = None
+
+
+class Result(BaseModel):
+    event: Optional[Event] = None

tests/main/conftest.py

@@ -30,6 +30,18 @@
     reason="Type annotation formatting differs with black < 24",
 )
 
+from datamodel_code_generator.format import PythonVersion, is_supported_in_black  # noqa: E402
+
+BLACK_PY313_SKIP = pytest.mark.skipif(
+    not is_supported_in_black(PythonVersion.PY_313),
+    reason=f"Installed black ({black.__version__}) doesn't support Python 3.13",
+)
+
+BLACK_PY314_SKIP = pytest.mark.skipif(
+    not is_supported_in_black(PythonVersion.PY_314),
+    reason=f"Installed black ({black.__version__}) doesn't support Python 3.14",
+)
+
 DATA_PATH: Path = Path(__file__).parent.parent / "data"
 EXPECTED_MAIN_PATH: Path = DATA_PATH / "expected" / "main"
 

tests/main/openapi/test_main_openapi.py

@@ -30,6 +30,8 @@
 from datamodel_code_generator.__main__ import Exit
 from tests.conftest import assert_directory_content, freeze_time
 from tests.main.conftest import (
+    BLACK_PY313_SKIP,
+    BLACK_PY314_SKIP,
     DATA_PATH,
     LEGACY_BLACK_SKIP,
     MSGSPEC_LEGACY_BLACK_SKIP,
@@ -333,6 +335,32 @@ def test_target_python_version(output_file: Path) -> None:
     )
 
 
+@BLACK_PY313_SKIP
+def test_target_python_version_313_has_future_annotations(output_file: Path) -> None:
+    """Test that Python 3.13 target includes future annotations import."""
+    with freeze_time(TIMESTAMP):
+        run_main_and_assert(
+            input_path=OPEN_API_DATA_PATH / "api.yaml",
+            output_path=output_file,
+            input_file_type=None,
+            assert_func=assert_file_content,
+            extra_args=["--target-python-version", "3.13"],
+        )
+
+
+@BLACK_PY314_SKIP
+def test_target_python_version_314_no_future_annotations(output_file: Path) -> None:
+    """Test that Python 3.14 target omits future annotations import (PEP 649)."""
+    with freeze_time(TIMESTAMP):
+        run_main_and_assert(
+            input_path=OPEN_API_DATA_PATH / "api.yaml",
+            output_path=output_file,
+            input_file_type=None,
+            assert_func=assert_file_content,
+            extra_args=["--target-python-version", "3.14"],
+        )
+
+
 @pytest.mark.benchmark
 def test_main_modular(output_dir: Path) -> None:
     """Test main function on modular file."""

tests/test_format.py

@@ -24,6 +24,16 @@ def test_python_version() -> None:
     _ = PythonVersion("{}.{}".format(*sys.version_info[:2]))
 
 
+def test_python_version_has_native_deferred_annotations() -> None:
+    """Test that has_native_deferred_annotations returns correct values for each Python version."""
+    assert not PythonVersion.PY_39.has_native_deferred_annotations
+    assert not PythonVersion.PY_310.has_native_deferred_annotations
+    assert not PythonVersion.PY_311.has_native_deferred_annotations
+    assert not PythonVersion.PY_312.has_native_deferred_annotations
+    assert not PythonVersion.PY_313.has_native_deferred_annotations
+    assert PythonVersion.PY_314.has_native_deferred_annotations
+
+
 @pytest.mark.parametrize(
     ("skip_string_normalization", "expected_output"),
     [