Drop Python 3.9 support in http-client-python (min Python 3.10) (#10500)

Copilot · msyyc · iscai-msft · web-flow · commit adc2a2ad87eb · 2026-04-28T04:14:19.000Z
- [x] `model_type.py`: Remove `sys.version_info &gt;= (3, 8)` version check
for `Literal` import — generator requires Python 3.10+, also removes
now-unused `sys` import
- [x] `client.py`: Change `Self` import generation to use
version-conditional import (`typing.Self` on 3.11+,
`typing_extensions.Self` on 3.10)
- [x] `model_base.py.jinja2`: Replace `from typing_extensions import
Self` with `if sys.version_info &gt;= (3, 11): from typing import Self
else: from typing_extensions import Self`
- [x] `serialization.py.jinja2`: Same `Self` conditional import pattern
- [x] `model_base.py.jinja2`: Replace `typing.Dict[str, typing.Any]`
with built-in `dict[str, typing.Any]`
- [x] `import_serializer.py`: Auto-add `import sys` when any
`version_modules` imports are present to fix `NameError: name 'sys' is
not defined` in generated `_client.py` files
- [x] Fix `wrong-import-position`/`reimported` lint errors: move
conditional `Self` block to end of imports in templates, remove
duplicate `import sys`, and emit versioned imports at end in
`_get_import_clauses`
- [ ] Validate via CI

---------

Co-authored-by: copilot-swe-agent[bot] &lt;198982749+Copilot@users.noreply.github.com&gt;
Co-authored-by: msyyc &lt;70930885+msyyc@users.noreply.github.com&gt;
Co-authored-by: Yuchao Yan &lt;yuchaoyan@microsoft.com&gt;
Co-authored-by: iscai-msft &lt;43154838+iscai-msft@users.noreply.github.com&gt;
diff --git a/.chronus/changes/python-drop-39-2026-4-27-6-50-0.md b/.chronus/changes/python-drop-39-2026-4-27-6-50-0.md
@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: deprecation
+packages:
+  - "@typespec/http-client-python"
+---
+
+Drop support for Python 3.9. The minimum supported Python version is now 3.10. Python 3.9 reached end-of-life and is no longer supported by upstream Python.
diff --git a/packages/http-client-python/emitter/src/run-python3.ts b/packages/http-client-python/emitter/src/run-python3.ts
@@ -11,7 +11,7 @@ import { patchPythonPath } from "./system-requirements.js";
 
 export async function runPython3(...args: string[]) {
   const command = await patchPythonPath(["python", ...args], {
-    version: ">=3.9",
+    version: ">=3.10",
     environmentVariable: "AUTOREST_PYTHON_EXE",
   });
   cp.execSync(command.join(" "), {
diff --git a/packages/http-client-python/eng/scripts/ci/config/mypy.ini b/packages/http-client-python/eng/scripts/ci/config/mypy.ini
@@ -1,6 +1,6 @@
 # global configurations
 [mypy]
-python_version = 3.9
+python_version = 3.10
 # Exclude mypy check for sub client tests
 exclude = .*/clientinitialization/.*\.py
 
diff --git a/packages/http-client-python/eng/scripts/ci/config/pylintrc b/packages/http-client-python/eng/scripts/ci/config/pylintrc
@@ -1,5 +1,5 @@
 [MASTER]
-py-version=3.9
+py-version=3.10
 ignore-patterns=test_*,conftest,setup
 reports=no
 
diff --git a/packages/http-client-python/eng/scripts/ci/config/pyrightconfig.json b/packages/http-client-python/eng/scripts/ci/config/pyrightconfig.json
@@ -2,5 +2,5 @@
   "reportUnnecessaryCast": "warning",
   "reportTypeCommentUsage": true,
   "reportMissingImports": false,
-  "pythonVersion": "3.9"
+  "pythonVersion": "3.10"
 }
diff --git a/packages/http-client-python/eng/scripts/ci/lint.ts b/packages/http-client-python/eng/scripts/ci/lint.ts
@@ -169,7 +169,7 @@ async function lintPygenSource(): Promise<boolean> {
     "generator/pygen",
     "--rcfile=eng/scripts/ci/config/pylintrc",
     "--recursive=y",
-    "--py-version=3.9",
+    "--py-version=3.10",
   ]);
 }
 
diff --git a/packages/http-client-python/eng/scripts/ci/run_pylint.py b/packages/http-client-python/eng/scripts/ci/run_pylint.py
@@ -43,7 +43,7 @@ def _single_dir_pylint(mod):
         "--evaluation=(max(0, 0 if fatal else 10.0 - ((float(5 * error + warning + refactor + convention + info)/ statement) * 10)))",
         "--output-format=parseable",
         "--recursive=y",
-        "--py-version=3.9",
+        "--py-version=3.10",
     ]
     if is_azure:
         pylint_args.append("--load-plugins=pylint_guidelines_checker")
diff --git a/packages/http-client-python/eng/scripts/setup/build_pygen_wheel.py b/packages/http-client-python/eng/scripts/setup/build_pygen_wheel.py
@@ -7,8 +7,8 @@
 # --------------------------------------------------------------------------
 import sys
 
-if not sys.version_info >= (3, 9, 0):
-    raise Exception("Autorest for Python extension requires Python 3.9 at least")
+if not sys.version_info >= (3, 10, 0):
+    raise Exception("Autorest for Python extension requires Python 3.10 at least")
 
 try:
     from package_manager import detect_package_manager, PackageManagerNotFoundError
@@ -18,7 +18,7 @@
     raise Exception("Your Python installation doesn't have a suitable package manager (pip or uv) available")
 
 
-# Now we have a package manager (pip or uv) and Py >= 3.9, go to work
+# Now we have a package manager (pip or uv) and Py >= 3.10, go to work
 
 from pathlib import Path
 
diff --git a/packages/http-client-python/eng/scripts/setup/install.py b/packages/http-client-python/eng/scripts/setup/install.py
@@ -7,9 +7,9 @@
 # --------------------------------------------------------------------------
 import sys
 
-if not sys.version_info >= (3, 9, 0):
+if not sys.version_info >= (3, 10, 0):
     print(
-        "Warning: Autorest for Python extension requires Python 3.9 at least. We will run your code with Pyodide since your Python version isn't adequate."
+        "Warning: Autorest for Python extension requires Python 3.10 at least. We will run your code with Pyodide since your Python version isn't adequate."
     )
     sys.exit(2)  # Exit code 2 for inadequate environment
 
@@ -32,7 +32,7 @@
     sys.exit(2)  # Exit code 2 for inadequate environment
 
 
-# Now we have a package manager (uv or pip) and Py >= 3.9, go to work
+# Now we have a package manager (uv or pip) and Py >= 3.10, go to work
 # At this point, both Python and package manager are confirmed to be available
 # Any failures from here should fail the npm install, not fallback to Pyodide
 
diff --git a/packages/http-client-python/eng/scripts/setup/install.ts b/packages/http-client-python/eng/scripts/setup/install.ts
@@ -7,7 +7,7 @@ async function main() {
   try {
     // First try to resolve Python path
     pythonCommand = await patchPythonPath(["python", "./eng/scripts/setup/install.py"], {
-      version: ">=3.9",
+      version: ">=3.10",
       environmentVariable: "AUTOREST_PYTHON_EXE",
     });
   } catch (error) {
diff --git a/packages/http-client-python/eng/scripts/setup/prepare.py b/packages/http-client-python/eng/scripts/setup/prepare.py
@@ -7,9 +7,9 @@
 # --------------------------------------------------------------------------
 import sys
 
-if not sys.version_info >= (3, 9, 0):
+if not sys.version_info >= (3, 10, 0):
     raise Warning(
-        "Autorest for Python extension requires Python 3.9 at least. We will run your code with Pyodide since your Python version isn't adequate."
+        "Autorest for Python extension requires Python 3.10 at least. We will run your code with Pyodide since your Python version isn't adequate."
     )
 
 from pathlib import Path
diff --git a/packages/http-client-python/eng/scripts/setup/run-python3.ts b/packages/http-client-python/eng/scripts/setup/run-python3.ts
@@ -11,7 +11,7 @@ import { patchPythonPath } from "./system-requirements.js";
 
 export async function runPython3(...args: string[]) {
   const command = await patchPythonPath(["python", ...args], {
-    version: ">=3.9",
+    version: ">=3.10",
     environmentVariable: "AUTOREST_PYTHON_EXE",
   });
   cp.execSync(command.join(" "), {
diff --git a/packages/http-client-python/generator/pygen/codegen/models/client.py b/packages/http-client-python/generator/pygen/codegen/models/client.py
@@ -291,11 +291,12 @@ def imports(self, async_mode: bool, **kwargs) -> FileImport:
                 ImportType.SDKCORE,
             )
 
-        # import for "Self"
+        # import for "Self" (typing.Self available from Python 3.11+)
         file_import.add_submodule_import(
             "typing_extensions",
             "Self",
             ImportType.STDLIB,
+            version_modules=(((3, 11), "typing", None),),
         )
         if self.need_cloud_setting:
             file_import.add_submodule_import("typing", "cast", ImportType.STDLIB)
diff --git a/packages/http-client-python/generator/pygen/codegen/models/model_type.py b/packages/http-client-python/generator/pygen/codegen/models/model_type.py
@@ -5,20 +5,14 @@
 # --------------------------------------------------------------------------
 from enum import Enum
 from collections import OrderedDict
-from typing import Any, Optional, TYPE_CHECKING, cast
-import sys
+from typing import Any, Literal, Optional, TYPE_CHECKING, cast
 from .utils import add_to_pylint_disable, NamespaceType, LOCALS_LENGTH_LIMIT
 from .base import BaseType
 from .constant_type import ConstantType
 from .property import Property
 from .imports import FileImport, ImportType, TypingSection
 from ...utils import NAME_LENGTH_LIMIT
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal  # type: ignore
-
 if TYPE_CHECKING:
     from .code_model import CodeModel
 
diff --git a/packages/http-client-python/generator/pygen/codegen/serializers/general_serializer.py b/packages/http-client-python/generator/pygen/codegen/serializers/general_serializer.py
@@ -28,7 +28,7 @@
     "corehttp": "1.0.0b6",
 }
 
-MIN_PYTHON_VERSION = "3.9"
+MIN_PYTHON_VERSION = "3.10"
 MAX_PYTHON_VERSION = "3.13"
 
 
diff --git a/packages/http-client-python/generator/pygen/codegen/serializers/import_serializer.py b/packages/http-client-python/generator/pygen/codegen/serializers/import_serializer.py
@@ -50,20 +50,25 @@ def _serialize_import_type(imports: list[ImportModel], delimiter: str) -> str:
     import_list = []
     for module_name in sorted(set(i.module_name for i in imports)):
         normal_imports = [i for i in imports if i.module_name == module_name and not i.version_modules]
-        versioned_imports = [i for i in imports if i.module_name == module_name and i.version_modules]
         if normal_imports:
             import_list.append(_serialize_package(normal_imports, delimiter))
-        for i in versioned_imports:
-            import_list.append(_serialize_versioned_package(i, delimiter))
     return delimiter.join(import_list)
 
 
+def _serialize_versioned_imports(imports: list[ImportModel], delimiter: str) -> str:
+    """Serialize all versioned imports together, to be emitted after all regular imports."""
+    return delimiter.join(_serialize_versioned_package(i, delimiter) for i in imports if i.version_modules)
+
+
 def _get_import_clauses(imports: list[ImportModel], delimiter: str) -> list[str]:
     import_clause = []
     for import_type in ImportType:
-        imports_with_import_type = [i for i in imports if i.import_type == import_type]
+        imports_with_import_type = [i for i in imports if i.import_type == import_type and not i.version_modules]
         if imports_with_import_type:
             import_clause.append(_serialize_import_type(imports_with_import_type, delimiter))
+    versioned = [i for i in imports if i.version_modules]
+    if versioned:
+        import_clause.append(_serialize_versioned_imports(versioned, delimiter))
     return import_clause
 
 
@@ -79,6 +84,13 @@ def _add_type_checking_import(self):
         if any(self.file_import.get_imports_from_section(TypingSection.TYPING)):
             self.file_import.add_submodule_import("typing", "TYPE_CHECKING", ImportType.STDLIB)
 
+    def _add_sys_import_if_needed(self):
+        all_imports = list(self.file_import.get_imports_from_section(TypingSection.REGULAR)) + list(
+            self.file_import.get_imports_from_section(TypingSection.TYPING)
+        )
+        if any(i.version_modules for i in all_imports):
+            self.file_import.add_import("sys", ImportType.STDLIB)
+
     def get_typing_definitions(self) -> str:
         def declare_definition(type_name: str, type_definition: TypeDefinition) -> list[str]:
             ret: list[str] = []
@@ -95,6 +107,7 @@ def declare_definition(type_name: str, type_definition: TypeDefinition) -> list[
 
     def __str__(self) -> str:
         self._add_type_checking_import()
+        self._add_sys_import_if_needed()
         regular_imports = ""
         regular_imports_list = self._get_imports_list(TypingSection.REGULAR)
 
diff --git a/packages/http-client-python/generator/pygen/codegen/templates/model_base.py.jinja2 b/packages/http-client-python/generator/pygen/codegen/templates/model_base.py.jinja2
@@ -19,17 +19,22 @@ from datetime import datetime, date, time, timedelta, timezone
 from json import JSONEncoder
 import xml.etree.ElementTree as ET
 from collections.abc import MutableMapping
-from typing_extensions import Self
 import isodate
 from {{ code_model.core_library }}.exceptions import DeserializationError
 from {{ code_model.core_library }}{{ "" if code_model.is_azure_flavor else ".utils" }} import CaseInsensitiveEnumMeta
 from {{ code_model.core_library }}.{{ "" if code_model.is_azure_flavor else "runtime." }}pipeline import PipelineResponse
 from {{ code_model.core_library }}.serialization import _Null
+
 {% if code_model.has_external_type %}
 from {{ code_model.core_library }}.serialization import TypeHandlerRegistry
 {% endif %}
 from {{ code_model.core_library }}.rest import HttpResponse
 
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self
+
 _LOGGER = logging.getLogger(__name__)
 
 __all__ = ["SdkJSONEncoder", "Model", "rest_field", "rest_discriminator"]
@@ -617,7 +622,7 @@ class Model(_MyMutableMapping):
         class_name = self.__class__.__name__
         if len(args) > 1:
             raise TypeError(f"{class_name}.__init__() takes 2 positional arguments but {len(args) + 1} were given")
-        dict_to_pass: typing.Dict[str, typing.Any] = {}
+        dict_to_pass: dict[str, typing.Any] = {}
         if args:
             if isinstance(args[0], ET.Element):
                 dict_to_pass.update(self._init_from_xml(args[0]))
diff --git a/packages/http-client-python/generator/pygen/codegen/templates/packaging_templates/README.md.jinja2 b/packages/http-client-python/generator/pygen/codegen/templates/packaging_templates/README.md.jinja2
@@ -3,7 +3,7 @@
 # Microsoft Azure SDK for Python
 
 This is the Microsoft {{options["package-pprint-name"]}} Client Library.
-This package has been tested with Python 3.9+.
+This package has been tested with Python 3.10+.
 For a more complete view of Azure libraries, see the [azure sdk python release](https://aka.ms/azsdk/python/all).
 
 # Usage
@@ -40,7 +40,7 @@ python -m pip install {{ options["package-name"] }}
 
 #### Prequisites
 
-- Python 3.9 or later is required to use this package.
+- Python 3.10 or later is required to use this package.
 - You need an [Azure subscription][azure_sub] to use this package.
 - An existing {{ options["package-pprint-name"] }} instance.
 
@@ -121,7 +121,7 @@ This package is generated by `@typespec/http-client-python` with Typespec.
 
 ### Prequisites
 
-- Python 3.9 or later is required to use this package.
+- Python 3.10 or later is required to use this package.
 
 ### Install the package
 
diff --git a/packages/http-client-python/generator/pygen/codegen/templates/serialization.py.jinja2 b/packages/http-client-python/generator/pygen/codegen/templates/serialization.py.jinja2
@@ -35,11 +35,15 @@ except ImportError:
 import xml.etree.ElementTree as ET
 
 import isodate  # type: ignore
-from typing_extensions import Self
 
 from {{ code_model.core_library }}.exceptions import DeserializationError, SerializationError
 from {{ code_model.core_library }}.serialization import NULL as CoreNull
 
+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self
+
 _BOM = codecs.BOM_UTF8.decode(encoding="utf-8")
 
 JSON = MutableMapping[str, Any]
diff --git a/packages/http-client-python/generator/setup.py b/packages/http-client-python/generator/setup.py
@@ -35,7 +35,6 @@
         "Development Status :: 4 - Beta",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",

Original file line number	Diff line number	Diff line change
`@@ -2,5 +2,5 @@`
`2`	`2`	`"reportUnnecessaryCast": "warning",`
`3`	`3`	`"reportTypeCommentUsage": true,`
`4`	`4`	`"reportMissingImports": false,`
`5`		`- "pythonVersion": "3.9"`
	`5`	`+ "pythonVersion": "3.10"`
`6`	`6`	`}`
Original file line number	Diff line number	Diff line change
`@@ -169,7 +169,7 @@ async function lintPygenSource(): Promise<boolean> {`
`169`	`169`	`"generator/pygen",`
`170`	`170`	`"--rcfile=eng/scripts/ci/config/pylintrc",`
`171`	`171`	`"--recursive=y",`
`172`		`- "--py-version=3.9",`
	`172`	`+ "--py-version=3.10",`
`173`	`173`	`]);`
`174`	`174`	`}`
`175`	`175`
Original file line number	Diff line number	Diff line change
`@@ -43,7 +43,7 @@ def _single_dir_pylint(mod):`
`43`	`43`	`"--evaluation=(max(0, 0 if fatal else 10.0 - ((float(5 * error + warning + refactor + convention + info)/ statement) * 10)))",`
`44`	`44`	`"--output-format=parseable",`
`45`	`45`	`"--recursive=y",`
`46`		`- "--py-version=3.9",`
	`46`	`+ "--py-version=3.10",`
`47`	`47`	`]`
`48`	`48`	`if is_azure:`
`49`	`49`	`pylint_args.append("--load-plugins=pylint_guidelines_checker")`