Compatibility with python 3.10 and 3.11

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.12']
+        python-version: ['3.10', '3.11', '3.12']
         os: [ubuntu-latest, macOS-latest, windows-latest]
 
     steps:
@@ -27,4 +27,4 @@ jobs:
           python -m pip install -e .[test]
       - name: Run tests
         run: |
-          python -m pytest tests
+          python -m pytest -v tests

.github/workflows/lint.yml

@@ -10,12 +10,16 @@ permissions:
 jobs:
   lint:
     runs-on: ubuntu-20.04
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ['3.10', '3.11', '3.12']
 
     steps:
-    - uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608
-    - name: Set up Python 3.12
-      uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
-      with:
-        python-version: 3.12
-    - name: Run pre-commit
-      uses: pre-commit/action@646c83fcd040023954eafda54b4db0192ce70507
+      - uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608
+      - name: 'Set up Python ${{ matrix.python-version }}'
+        uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
+        with:
+          python-version: '${{ matrix.python-version }}'
+      - name: Run pre-commit
+        uses: pre-commit/action@646c83fcd040023954eafda54b4db0192ce70507

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "aws-sdk-signers"
-requires-python = ">=3.12"
+requires-python = ">=3.10"
 authors = [
   {name = "Amazon Web Services"},
 ]
@@ -14,10 +14,15 @@ license = {file = "LICENSE"}
 keywords = ["AWS", "Signing", "SigV4", "HTTP"]
 classifiers = [
   "Development Status :: 2 - Pre-Alpha",
+  "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python"
 ]
 dynamic = ["version"]
+dependencies = [
+    'typing-extensions >=4.12.2,<5 ; python_version == "3.10"',
+]
 
 [project.optional-dependencies]
 test = [
@@ -38,8 +43,6 @@ path = "src/aws_sdk_signers/_version.py"
 line-length = 88
 indent-width = 4
 
-target-version = "py312"
-
 [tool.ruff.lint]
 select = ["E4", "E7", "E9", "F", "I", "UP"]
 ignore = []

src/aws_sdk_signers/_http.py

@@ -12,6 +12,7 @@
 
 from __future__ import annotations
 
+import sys
 from collections import Counter, OrderedDict
 from collections.abc import AsyncIterable, Iterable, Iterator
 from copy import deepcopy
@@ -210,7 +211,12 @@ def __len__(self) -> int:
         return len(self.entries)
 
     def __repr__(self) -> str:
-        return f"Fields({self.entries})"
+        if sys.version_info < (3, 12):
+            # Dicts are ordered in 3.11 and 3.10, so it's safe to use dict.
+            # Used to mock a 3.12-like output.
+            return f"Fields(OrderedDict({dict(self.entries)}))"
+        else:
+            return f"Fields({self.entries})"
 
     def __contains__(self, key: str) -> bool:
         return self._normalize_field_name(key) in self.entries

src/aws_sdk_signers/_identity.py

@@ -3,11 +3,19 @@
 SPDX-License-Identifier: Apache-2.0
 """
 
+import sys
 from dataclasses import dataclass
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 
 from .interfaces.identity import Identity
 
+if sys.version_info < (3, 12):
+    from datetime import timezone
+
+    UTC = timezone.utc
+else:
+    from datetime import UTC
+
 
 @dataclass(kw_only=True)
 class AWSCredentialIdentity(Identity):

src/aws_sdk_signers/_io.py

@@ -3,13 +3,16 @@
 SPDX-License-Identifier: Apache-2.0
 """
 
+import sys
 from asyncio import iscoroutinefunction
 from collections.abc import AsyncIterable, AsyncIterator, Awaitable, Callable
 from io import BytesIO
-from typing import (
-    Self,
-    cast,
-)
+from typing import cast
+
+if sys.version_info < (3, 11):
+    from typing_extensions import Self
+else:
+    from typing import Self
 
 from aws_sdk_signers.interfaces.io import AsyncByteStream, ByteStream
 

src/aws_sdk_signers/signers.py

@@ -6,18 +6,31 @@
 import datetime
 import hmac
 import io
+import sys
 import warnings
 from collections.abc import AsyncIterable
 from copy import deepcopy
 from hashlib import sha256
-from typing import Required, TypedDict
+from typing import TypedDict
 from urllib.parse import parse_qsl, quote
 
+if sys.version_info < (3, 11):
+    from typing_extensions import Required
+else:
+    from typing import Required
+
 from ._http import URI, AWSRequest, Field
 from ._identity import AWSCredentialIdentity
 from ._io import AsyncBytesReader
 from .exceptions import AWSSDKWarning, MissingExpectedParameterException
 
+if sys.version_info < (3, 12):
+    from datetime import timezone
+
+    UTC = timezone.utc
+else:
+    from datetime import UTC
+
 HEADERS_EXCLUDED_FROM_SIGNING: tuple[str, ...] = (
     "accept",
     "accept-encoding",
@@ -185,7 +198,7 @@ def _generate_new_request(self, *, request: AWSRequest) -> AWSRequest:
 
     def _resolve_signing_date(self, *, date: str | None) -> str:
         if date is None:
-            date_obj = datetime.datetime.now(datetime.UTC)
+            date_obj = datetime.datetime.now(UTC)
             date = date_obj.strftime(SIGV4_TIMESTAMP_FORMAT)
         return date
 
@@ -548,7 +561,7 @@ async def _generate_new_request(self, *, request: AWSRequest) -> AWSRequest:
 
     async def _resolve_signing_date(self, *, date: str | None) -> str:
         if date is None:
-            date_obj = datetime.datetime.now(datetime.UTC)
+            date_obj = datetime.datetime.now(UTC)
             date = date_obj.strftime(SIGV4_TIMESTAMP_FORMAT)
         return date
 

tests/unit/auth/test_sigv4.py

@@ -1,8 +1,9 @@
 import os
 import pathlib
 import re
+import sys
 from collections.abc import Iterable
-from datetime import UTC, datetime
+from datetime import datetime
 from http.server import BaseHTTPRequestHandler
 from io import BytesIO
 
@@ -24,6 +25,13 @@
 )
 from freezegun import freeze_time
 
+if sys.version_info < (3, 12):
+    from datetime import timezone
+
+    UTC = timezone.utc
+else:
+    from datetime import UTC
+
 SECRET_KEY: str = "wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY"
 ACCESS_KEY: str = "AKIDEXAMPLE"
 SERVICE: str = "service"

tests/unit/test_identity.py

@@ -1,8 +1,16 @@
-from datetime import UTC, datetime, timedelta
+import sys
+from datetime import datetime, timedelta
 
 import pytest
 from aws_sdk_signers import AWSCredentialIdentity
 
+if sys.version_info < (3, 12):
+    from datetime import timezone
+
+    UTC = timezone.utc
+else:
+    from datetime import UTC
+
 
 @pytest.mark.parametrize(
     "access_key_id,secret_access_key,session_token,expiration",

tests/unit/test_signers.py

@@ -4,8 +4,9 @@
 """
 
 import re
+import sys
 import typing
-from datetime import UTC, datetime
+from datetime import datetime
 from io import BytesIO
 
 import pytest
@@ -19,6 +20,13 @@
     SigV4SigningProperties,
 )
 
+if sys.version_info < (3, 12):
+    from datetime import timezone
+
+    UTC = timezone.utc
+else:
+    from datetime import UTC
+
 SIGV4_RE = re.compile(
     r"AWS4-HMAC-SHA256 "
     r"Credential=(?P<access_key>\w+)/\d+/"