From 637c4e16cd43eed0d70c7868c8c6415967de5673 Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Tue, 29 Dec 2020 21:43:01 +0000
Subject: [PATCH 01/10] Import from typing if available.

---
 aiohttp/client.py            | 6 +++++-
 aiohttp/hdrs.py              | 6 +++++-
 aiohttp/helpers.py           | 6 +++---
 aiohttp/http_parser.py       | 6 +++++-
 aiohttp/http_websocket.py    | 7 +++++--
 aiohttp/locks.py             | 7 +------
 aiohttp/payload.py           | 6 +++++-
 aiohttp/streams.py           | 8 +++-----
 aiohttp/tracing.py           | 5 ++++-
 aiohttp/web_fileresponse.py  | 7 +++++--
 aiohttp/web_request.py       | 6 +++++-
 aiohttp/web_urldispatcher.py | 6 +++++-
 aiohttp/web_ws.py            | 6 +++++-
 setup.py                     | 2 +-
 14 files changed, 57 insertions(+), 27 deletions(-)

diff --git a/aiohttp/client.py b/aiohttp/client.py
index f0f21f5faca..37ad411928f 100644
--- a/aiohttp/client.py
+++ b/aiohttp/client.py
@@ -30,7 +30,6 @@
 
 import attr
 from multidict import CIMultiDict, MultiDict, MultiDictProxy, istr
-from typing_extensions import Final
 from yarl import URL
 
 from . import hdrs, http, payload
@@ -88,6 +87,11 @@
 from .tracing import Trace, TraceConfig
 from .typedefs import JSONEncoder, LooseCookies, LooseHeaders, StrOrURL
 
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
+
 __all__ = (
     # client_exceptions
     "ClientConnectionError",
diff --git a/aiohttp/hdrs.py b/aiohttp/hdrs.py
index d7d8e5000f3..38b03c18a1a 100644
--- a/aiohttp/hdrs.py
+++ b/aiohttp/hdrs.py
@@ -5,7 +5,11 @@
 from typing import Set
 
 from multidict import istr
-from typing_extensions import Final
+
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
 
 METH_ANY: Final[str] = "*"
 METH_CONNECT: Final[str] = "CONNECT"
diff --git a/aiohttp/helpers.py b/aiohttp/helpers.py
index a6b14025827..5b2e613a9e5 100644
--- a/aiohttp/helpers.py
+++ b/aiohttp/helpers.py
@@ -23,6 +23,7 @@
 from typing import (
     Any,
     Callable,
+    ContextManager,
     Dict,
     Generator,
     Generic,
@@ -45,7 +46,6 @@
 import async_timeout
 import attr
 from multidict import MultiDict, MultiDictProxy
-from typing_extensions import Protocol
 from yarl import URL
 
 from . import hdrs
@@ -64,9 +64,9 @@
     idna_ssl.patch_match_hostname()
 
 try:
-    from typing import ContextManager
+    from typing import Protocol
 except ImportError:
-    from typing_extensions import ContextManager
+    from typing_extensions import Protocol
 
 
 def all_tasks(
diff --git a/aiohttp/http_parser.py b/aiohttp/http_parser.py
index d3011633165..18a86e20992 100644
--- a/aiohttp/http_parser.py
+++ b/aiohttp/http_parser.py
@@ -20,7 +20,6 @@
 )
 
 from multidict import CIMultiDict, CIMultiDictProxy, istr
-from typing_extensions import Final
 from yarl import URL
 
 from . import hdrs
@@ -39,6 +38,11 @@
 from .streams import EMPTY_PAYLOAD, StreamReader
 from .typedefs import RawHeaders
 
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
+
 try:
     import brotli
 
diff --git a/aiohttp/http_websocket.py b/aiohttp/http_websocket.py
index aaa169d92d4..2a1455f50b5 100644
--- a/aiohttp/http_websocket.py
+++ b/aiohttp/http_websocket.py
@@ -11,12 +11,15 @@
 from struct import Struct
 from typing import Any, Callable, List, Optional, Pattern, Set, Tuple, Union
 
-from typing_extensions import Final
-
 from .base_protocol import BaseProtocol
 from .helpers import NO_EXTENSIONS
 from .streams import DataQueue
 
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
+
 __all__ = (
     "WS_CLOSED_MESSAGE",
     "WS_CLOSING_MESSAGE",
diff --git a/aiohttp/locks.py b/aiohttp/locks.py
index ce5b9c6f731..f3456af781d 100644
--- a/aiohttp/locks.py
+++ b/aiohttp/locks.py
@@ -1,11 +1,6 @@
 import asyncio
 import collections
-from typing import Any, Optional
-
-try:
-    from typing import Deque
-except ImportError:
-    from typing_extensions import Deque
+from typing import Any, Deque, Optional
 
 
 class EventResultOrError:
diff --git a/aiohttp/payload.py b/aiohttp/payload.py
index 801730ebe63..3a08562f93c 100644
--- a/aiohttp/payload.py
+++ b/aiohttp/payload.py
@@ -23,7 +23,6 @@
 )
 
 from multidict import CIMultiDict
-from typing_extensions import Final
 
 from . import hdrs
 from .abc import AbstractStreamWriter
@@ -37,6 +36,11 @@
 from .streams import StreamReader
 from .typedefs import JSONEncoder, _CIMultiDict
 
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
+
 __all__ = (
     "PAYLOAD_REGISTRY",
     "get_payload",
diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index b450143a7fb..78f40ade40f 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -1,18 +1,16 @@
 import asyncio
 import collections
 import warnings
-from typing import Awaitable, Callable, Generic, List, Optional, Tuple, TypeVar
-
-from typing_extensions import Final
+from typing import Awaitable, Callable, Deque, Generic, List, Optional, Tuple, TypeVar
 
 from .base_protocol import BaseProtocol
 from .helpers import BaseTimerContext, set_exception, set_result
 from .log import internal_logger
 
 try:  # pragma: no cover
-    from typing import Deque
+    from typing import Final
 except ImportError:
-    from typing_extensions import Deque
+    from typing_extensions import Final
 
 __all__ = (
     "EMPTY_PAYLOAD",
diff --git a/aiohttp/tracing.py b/aiohttp/tracing.py
index 4b04b67f28e..57888a78248 100644
--- a/aiohttp/tracing.py
+++ b/aiohttp/tracing.py
@@ -9,7 +9,10 @@
 from .client_reqrep import ClientResponse
 
 if TYPE_CHECKING:  # pragma: no cover
-    from typing_extensions import Protocol
+    try:
+        from typing import Protocol
+    except ImportError:
+        from typing_extensions import Protocol
 
     from .client import ClientSession
 
diff --git a/aiohttp/web_fileresponse.py b/aiohttp/web_fileresponse.py
index 6e475010fc2..5910a0fa8e4 100644
--- a/aiohttp/web_fileresponse.py
+++ b/aiohttp/web_fileresponse.py
@@ -15,8 +15,6 @@
     cast,
 )
 
-from typing_extensions import Final
-
 from . import hdrs
 from .abc import AbstractStreamWriter
 from .typedefs import LooseHeaders
@@ -28,6 +26,11 @@
 )
 from .web_response import StreamResponse
 
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
+
 __all__ = ("FileResponse",)
 
 if TYPE_CHECKING:  # pragma: no cover
diff --git a/aiohttp/web_request.py b/aiohttp/web_request.py
index 376ead26157..c842d3c6207 100644
--- a/aiohttp/web_request.py
+++ b/aiohttp/web_request.py
@@ -27,7 +27,6 @@
 
 import attr
 from multidict import CIMultiDict, CIMultiDictProxy, MultiDict, MultiDictProxy
-from typing_extensions import Final
 from yarl import URL
 
 from . import hdrs
@@ -47,6 +46,11 @@
 from .web_exceptions import HTTPRequestEntityTooLarge
 from .web_response import StreamResponse
 
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
+
 __all__ = ("BaseRequest", "FileField", "Request")
 
 
diff --git a/aiohttp/web_urldispatcher.py b/aiohttp/web_urldispatcher.py
index aa4ece7320b..f7ac32afa8e 100644
--- a/aiohttp/web_urldispatcher.py
+++ b/aiohttp/web_urldispatcher.py
@@ -33,7 +33,6 @@
     cast,
 )
 
-from typing_extensions import Final, TypedDict
 from yarl import URL, __version__ as yarl_version  # type: ignore
 
 from . import hdrs
@@ -53,6 +52,11 @@
 from .web_response import Response, StreamResponse
 from .web_routedef import AbstractRouteDef
 
+try:
+    from typing import Final, TypedDict
+except ImportError:
+    from typing_extensions import Final, TypedDict
+
 __all__ = (
     "UrlDispatcher",
     "UrlMappingMatchInfo",
diff --git a/aiohttp/web_ws.py b/aiohttp/web_ws.py
index 42a8d143752..54db21e3a41 100644
--- a/aiohttp/web_ws.py
+++ b/aiohttp/web_ws.py
@@ -8,7 +8,6 @@
 import async_timeout
 import attr
 from multidict import CIMultiDict
-from typing_extensions import Final
 
 from . import hdrs
 from .abc import AbstractStreamWriter
@@ -33,6 +32,11 @@
 from .web_request import BaseRequest
 from .web_response import StreamResponse
 
+try:
+    from typing import Final
+except ImportError:
+    from typing_extensions import Final
+
 __all__ = (
     "WebSocketResponse",
     "WebSocketReady",
diff --git a/setup.py b/setup.py
index 254fa13ab74..839010faae9 100644
--- a/setup.py
+++ b/setup.py
@@ -70,7 +70,7 @@ def build_extension(self, ext):
     'asynctest==0.13.0; python_version<"3.8"',
     "yarl>=1.0,<2.0",
     'idna-ssl>=1.0; python_version<"3.7"',
-    "typing_extensions>=3.7.4",
+    'typing_extensions>=3.7.4; python_version<"3.8"',
     "frozenlist>=1.1.1",
     "aiosignal>=1.1.2",
 ]

From e0801b81fa914829380befc8133100441457a612 Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Tue, 29 Dec 2020 22:22:13 +0000
Subject: [PATCH 02/10] Use sys.version_info instead of try/except.

---
 aiohttp/client.py            | 4 ++--
 aiohttp/hdrs.py              | 5 +++--
 aiohttp/helpers.py           | 4 ++--
 aiohttp/http_parser.py       | 5 +++--
 aiohttp/http_websocket.py    | 4 ++--
 aiohttp/payload.py           | 5 +++--
 aiohttp/streams.py           | 5 +++--
 aiohttp/tracing.py           | 5 +++--
 aiohttp/web_fileresponse.py  | 4 ++--
 aiohttp/web_request.py       | 5 +++--
 aiohttp/web_urldispatcher.py | 5 +++--
 aiohttp/web_ws.py            | 5 +++--
 12 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/aiohttp/client.py b/aiohttp/client.py
index 37ad411928f..9df0ce7fd5b 100644
--- a/aiohttp/client.py
+++ b/aiohttp/client.py
@@ -87,9 +87,9 @@
 from .tracing import Trace, TraceConfig
 from .typedefs import JSONEncoder, LooseCookies, LooseHeaders, StrOrURL
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 __all__ = (
diff --git a/aiohttp/hdrs.py b/aiohttp/hdrs.py
index 38b03c18a1a..a619f2543e4 100644
--- a/aiohttp/hdrs.py
+++ b/aiohttp/hdrs.py
@@ -2,13 +2,14 @@
 
 # After changing the file content call ./tools/gen.py
 # to regenerate the headers parser
+import sys
 from typing import Set
 
 from multidict import istr
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 METH_ANY: Final[str] = "*"
diff --git a/aiohttp/helpers.py b/aiohttp/helpers.py
index 5b2e613a9e5..09bd748669d 100644
--- a/aiohttp/helpers.py
+++ b/aiohttp/helpers.py
@@ -63,9 +63,9 @@
 
     idna_ssl.patch_match_hostname()
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Protocol
-except ImportError:
+else:
     from typing_extensions import Protocol
 
 
diff --git a/aiohttp/http_parser.py b/aiohttp/http_parser.py
index 18a86e20992..903270d24d7 100644
--- a/aiohttp/http_parser.py
+++ b/aiohttp/http_parser.py
@@ -3,6 +3,7 @@
 import collections
 import re
 import string
+import sys
 import zlib
 from contextlib import suppress
 from enum import IntEnum
@@ -38,9 +39,9 @@
 from .streams import EMPTY_PAYLOAD, StreamReader
 from .typedefs import RawHeaders
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 try:
diff --git a/aiohttp/http_websocket.py b/aiohttp/http_websocket.py
index 2a1455f50b5..f7972d732e9 100644
--- a/aiohttp/http_websocket.py
+++ b/aiohttp/http_websocket.py
@@ -15,9 +15,9 @@
 from .helpers import NO_EXTENSIONS
 from .streams import DataQueue
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 __all__ = (
diff --git a/aiohttp/payload.py b/aiohttp/payload.py
index 3a08562f93c..0c9c6f76b8f 100644
--- a/aiohttp/payload.py
+++ b/aiohttp/payload.py
@@ -4,6 +4,7 @@
 import json
 import mimetypes
 import os
+import sys
 import warnings
 from abc import ABC, abstractmethod
 from itertools import chain
@@ -36,9 +37,9 @@
 from .streams import StreamReader
 from .typedefs import JSONEncoder, _CIMultiDict
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 __all__ = (
diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index 78f40ade40f..1770638463a 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -1,5 +1,6 @@
 import asyncio
 import collections
+import sys
 import warnings
 from typing import Awaitable, Callable, Deque, Generic, List, Optional, Tuple, TypeVar
 
@@ -7,9 +8,9 @@
 from .helpers import BaseTimerContext, set_exception, set_result
 from .log import internal_logger
 
-try:  # pragma: no cover
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 __all__ = (
diff --git a/aiohttp/tracing.py b/aiohttp/tracing.py
index 57888a78248..16c58fb11e8 100644
--- a/aiohttp/tracing.py
+++ b/aiohttp/tracing.py
@@ -1,3 +1,4 @@
+import sys
 from types import SimpleNamespace
 from typing import TYPE_CHECKING, Awaitable, Optional, Type, TypeVar
 
@@ -9,9 +10,9 @@
 from .client_reqrep import ClientResponse
 
 if TYPE_CHECKING:  # pragma: no cover
-    try:
+    if sys.version_info >= (3, 8):
         from typing import Protocol
-    except ImportError:
+    else:
         from typing_extensions import Protocol
 
     from .client import ClientSession
diff --git a/aiohttp/web_fileresponse.py b/aiohttp/web_fileresponse.py
index 5910a0fa8e4..15283ddbda1 100644
--- a/aiohttp/web_fileresponse.py
+++ b/aiohttp/web_fileresponse.py
@@ -26,9 +26,9 @@
 )
 from .web_response import StreamResponse
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 __all__ = ("FileResponse",)
diff --git a/aiohttp/web_request.py b/aiohttp/web_request.py
index c842d3c6207..744a2e34396 100644
--- a/aiohttp/web_request.py
+++ b/aiohttp/web_request.py
@@ -4,6 +4,7 @@
 import re
 import socket
 import string
+import sys
 import tempfile
 import types
 import warnings
@@ -46,9 +47,9 @@
 from .web_exceptions import HTTPRequestEntityTooLarge
 from .web_response import StreamResponse
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 __all__ = ("BaseRequest", "FileField", "Request")
diff --git a/aiohttp/web_urldispatcher.py b/aiohttp/web_urldispatcher.py
index f7ac32afa8e..f27a5bb6e5d 100644
--- a/aiohttp/web_urldispatcher.py
+++ b/aiohttp/web_urldispatcher.py
@@ -6,6 +6,7 @@
 import keyword
 import os
 import re
+import sys
 import warnings
 from contextlib import contextmanager
 from functools import wraps
@@ -52,9 +53,9 @@
 from .web_response import Response, StreamResponse
 from .web_routedef import AbstractRouteDef
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final, TypedDict
-except ImportError:
+else:
     from typing_extensions import Final, TypedDict
 
 __all__ = (
diff --git a/aiohttp/web_ws.py b/aiohttp/web_ws.py
index 54db21e3a41..badf6a189c0 100644
--- a/aiohttp/web_ws.py
+++ b/aiohttp/web_ws.py
@@ -3,6 +3,7 @@
 import binascii
 import hashlib
 import json
+import sys
 from typing import Any, Iterable, Optional, Tuple
 
 import async_timeout
@@ -32,9 +33,9 @@
 from .web_request import BaseRequest
 from .web_response import StreamResponse
 
-try:
+if sys.version_info >= (3, 8):
     from typing import Final
-except ImportError:
+else:
     from typing_extensions import Final
 
 __all__ = (

From d44e1e20417773daae26836e8dd336feaca50697 Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Tue, 29 Dec 2020 22:25:23 +0000
Subject: [PATCH 03/10] Add change file.

---
 CHANGES/5107.bugfix | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 CHANGES/5107.bugfix

diff --git a/CHANGES/5107.bugfix b/CHANGES/5107.bugfix
new file mode 100644
index 00000000000..4287bfad126
--- /dev/null
+++ b/CHANGES/5107.bugfix
@@ -0,0 +1 @@
+Only depend on typing_extensions for Python <3.8

From eb2669b0dc6a8fb439ef5bbe54ba740dfa823720 Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Mon, 4 Jan 2021 18:12:20 +0000
Subject: [PATCH 04/10] Import from typedefs.

---
 aiohttp/client.py            | 7 +------
 aiohttp/hdrs.py              | 6 +-----
 aiohttp/helpers.py           | 7 +------
 aiohttp/http_parser.py       | 8 +-------
 aiohttp/http_websocket.py    | 6 +-----
 aiohttp/payload.py           | 8 +-------
 aiohttp/streams.py           | 7 +------
 aiohttp/tracing.py           | 7 +------
 aiohttp/typedefs.py          | 5 +++++
 aiohttp/web_fileresponse.py  | 7 +------
 aiohttp/web_request.py       | 7 +------
 aiohttp/web_urldispatcher.py | 8 +-------
 aiohttp/web_ws.py            | 8 +-------
 13 files changed, 17 insertions(+), 74 deletions(-)

diff --git a/aiohttp/client.py b/aiohttp/client.py
index 9df0ce7fd5b..a65324e9f71 100644
--- a/aiohttp/client.py
+++ b/aiohttp/client.py
@@ -85,12 +85,7 @@
 from .http_websocket import WSHandshakeError, WSMessage, ws_ext_gen, ws_ext_parse
 from .streams import FlowControlDataQueue
 from .tracing import Trace, TraceConfig
-from .typedefs import JSONEncoder, LooseCookies, LooseHeaders, StrOrURL
-
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
+from .typedefs import Final, JSONEncoder, LooseCookies, LooseHeaders, StrOrURL
 
 __all__ = (
     # client_exceptions
diff --git a/aiohttp/hdrs.py b/aiohttp/hdrs.py
index a619f2543e4..e1896d60429 100644
--- a/aiohttp/hdrs.py
+++ b/aiohttp/hdrs.py
@@ -2,15 +2,11 @@
 
 # After changing the file content call ./tools/gen.py
 # to regenerate the headers parser
-import sys
 from typing import Set
 
 from multidict import istr
 
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
+from .typedefs import Final
 
 METH_ANY: Final[str] = "*"
 METH_CONNECT: Final[str] = "CONNECT"
diff --git a/aiohttp/helpers.py b/aiohttp/helpers.py
index 09bd748669d..162869d8842 100644
--- a/aiohttp/helpers.py
+++ b/aiohttp/helpers.py
@@ -50,7 +50,7 @@
 
 from . import hdrs
 from .log import client_logger, internal_logger
-from .typedefs import PathLike  # noqa
+from .typedefs import PathLike, Protocol  # noqa
 
 __all__ = ("BasicAuth", "ChainMapProxy")
 
@@ -63,11 +63,6 @@
 
     idna_ssl.patch_match_hostname()
 
-if sys.version_info >= (3, 8):
-    from typing import Protocol
-else:
-    from typing_extensions import Protocol
-
 
 def all_tasks(
     loop: Optional[asyncio.AbstractEventLoop] = None,
diff --git a/aiohttp/http_parser.py b/aiohttp/http_parser.py
index 903270d24d7..6781e901921 100644
--- a/aiohttp/http_parser.py
+++ b/aiohttp/http_parser.py
@@ -3,7 +3,6 @@
 import collections
 import re
 import string
-import sys
 import zlib
 from contextlib import suppress
 from enum import IntEnum
@@ -37,12 +36,7 @@
 from .http_writer import HttpVersion, HttpVersion10
 from .log import internal_logger
 from .streams import EMPTY_PAYLOAD, StreamReader
-from .typedefs import RawHeaders
-
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
+from .typedefs import Final, RawHeaders
 
 try:
     import brotli
diff --git a/aiohttp/http_websocket.py b/aiohttp/http_websocket.py
index f7972d732e9..ff490e112cd 100644
--- a/aiohttp/http_websocket.py
+++ b/aiohttp/http_websocket.py
@@ -14,11 +14,7 @@
 from .base_protocol import BaseProtocol
 from .helpers import NO_EXTENSIONS
 from .streams import DataQueue
-
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
+from .typedefs import Final
 
 __all__ = (
     "WS_CLOSED_MESSAGE",
diff --git a/aiohttp/payload.py b/aiohttp/payload.py
index 0c9c6f76b8f..eaef597f3db 100644
--- a/aiohttp/payload.py
+++ b/aiohttp/payload.py
@@ -4,7 +4,6 @@
 import json
 import mimetypes
 import os
-import sys
 import warnings
 from abc import ABC, abstractmethod
 from itertools import chain
@@ -35,12 +34,7 @@
     sentinel,
 )
 from .streams import StreamReader
-from .typedefs import JSONEncoder, _CIMultiDict
-
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
+from .typedefs import Final, JSONEncoder, _CIMultiDict
 
 __all__ = (
     "PAYLOAD_REGISTRY",
diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index 1770638463a..2822ede10f7 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -1,17 +1,12 @@
 import asyncio
 import collections
-import sys
 import warnings
 from typing import Awaitable, Callable, Deque, Generic, List, Optional, Tuple, TypeVar
 
 from .base_protocol import BaseProtocol
 from .helpers import BaseTimerContext, set_exception, set_result
 from .log import internal_logger
-
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
+from .typedefs import Final
 
 __all__ = (
     "EMPTY_PAYLOAD",
diff --git a/aiohttp/tracing.py b/aiohttp/tracing.py
index 16c58fb11e8..a4d188f147b 100644
--- a/aiohttp/tracing.py
+++ b/aiohttp/tracing.py
@@ -1,4 +1,3 @@
-import sys
 from types import SimpleNamespace
 from typing import TYPE_CHECKING, Awaitable, Optional, Type, TypeVar
 
@@ -10,11 +9,7 @@
 from .client_reqrep import ClientResponse
 
 if TYPE_CHECKING:  # pragma: no cover
-    if sys.version_info >= (3, 8):
-        from typing import Protocol
-    else:
-        from typing_extensions import Protocol
-
+    from .typedefs import Protocol
     from .client import ClientSession
 
     _ParamT_contra = TypeVar("_ParamT_contra", contravariant=True)
diff --git a/aiohttp/typedefs.py b/aiohttp/typedefs.py
index 1b68a242af5..b550e85942e 100644
--- a/aiohttp/typedefs.py
+++ b/aiohttp/typedefs.py
@@ -7,6 +7,11 @@
 from multidict import CIMultiDict, CIMultiDictProxy, MultiDict, MultiDictProxy, istr
 from yarl import URL
 
+if sys.version_info >= (3, 8):
+    from typing import Final, Protocol, TypedDict
+else:
+    from typing_extensions import Final, Protocol, TypedDict
+
 DEFAULT_JSON_ENCODER = json.dumps
 DEFAULT_JSON_DECODER = json.loads
 
diff --git a/aiohttp/web_fileresponse.py b/aiohttp/web_fileresponse.py
index 15283ddbda1..207d6a39712 100644
--- a/aiohttp/web_fileresponse.py
+++ b/aiohttp/web_fileresponse.py
@@ -17,7 +17,7 @@
 
 from . import hdrs
 from .abc import AbstractStreamWriter
-from .typedefs import LooseHeaders
+from .typedefs import Final, LooseHeaders
 from .web_exceptions import (
     HTTPNotModified,
     HTTPPartialContent,
@@ -26,11 +26,6 @@
 )
 from .web_response import StreamResponse
 
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
-
 __all__ = ("FileResponse",)
 
 if TYPE_CHECKING:  # pragma: no cover
diff --git a/aiohttp/web_request.py b/aiohttp/web_request.py
index 744a2e34396..91b9e6b1deb 100644
--- a/aiohttp/web_request.py
+++ b/aiohttp/web_request.py
@@ -4,7 +4,6 @@
 import re
 import socket
 import string
-import sys
 import tempfile
 import types
 import warnings
@@ -39,6 +38,7 @@
 from .streams import EmptyStreamReader, StreamReader
 from .typedefs import (
     DEFAULT_JSON_DECODER,
+    Final,
     JSONDecoder,
     LooseHeaders,
     RawHeaders,
@@ -47,11 +47,6 @@
 from .web_exceptions import HTTPRequestEntityTooLarge
 from .web_response import StreamResponse
 
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
-
 __all__ = ("BaseRequest", "FileField", "Request")
 
 
diff --git a/aiohttp/web_urldispatcher.py b/aiohttp/web_urldispatcher.py
index f27a5bb6e5d..e5031141c31 100644
--- a/aiohttp/web_urldispatcher.py
+++ b/aiohttp/web_urldispatcher.py
@@ -6,7 +6,6 @@
 import keyword
 import os
 import re
-import sys
 import warnings
 from contextlib import contextmanager
 from functools import wraps
@@ -40,7 +39,7 @@
 from .abc import AbstractMatchInfo, AbstractRouter, AbstractView
 from .helpers import DEBUG
 from .http import HttpVersion11
-from .typedefs import PathLike
+from .typedefs import Final, PathLike, TypedDict
 from .web_exceptions import (
     HTTPException,
     HTTPExpectationFailed,
@@ -53,11 +52,6 @@
 from .web_response import Response, StreamResponse
 from .web_routedef import AbstractRouteDef
 
-if sys.version_info >= (3, 8):
-    from typing import Final, TypedDict
-else:
-    from typing_extensions import Final, TypedDict
-
 __all__ = (
     "UrlDispatcher",
     "UrlMappingMatchInfo",
diff --git a/aiohttp/web_ws.py b/aiohttp/web_ws.py
index badf6a189c0..3ec5d8e7484 100644
--- a/aiohttp/web_ws.py
+++ b/aiohttp/web_ws.py
@@ -3,7 +3,6 @@
 import binascii
 import hashlib
 import json
-import sys
 from typing import Any, Iterable, Optional, Tuple
 
 import async_timeout
@@ -28,16 +27,11 @@
 )
 from .log import ws_logger
 from .streams import EofStream, FlowControlDataQueue
-from .typedefs import JSONDecoder, JSONEncoder
+from .typedefs import Final, JSONDecoder, JSONEncoder
 from .web_exceptions import HTTPBadRequest, HTTPException
 from .web_request import BaseRequest
 from .web_response import StreamResponse
 
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
-
 __all__ = (
     "WebSocketResponse",
     "WebSocketReady",

From 4801dd17a34945f8436a7f4162cb6920e3d4e2db Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Mon, 4 Jan 2021 18:17:32 +0000
Subject: [PATCH 05/10] Order imports.

---
 aiohttp/tracing.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aiohttp/tracing.py b/aiohttp/tracing.py
index a4d188f147b..0d119ebbc58 100644
--- a/aiohttp/tracing.py
+++ b/aiohttp/tracing.py
@@ -9,8 +9,8 @@
 from .client_reqrep import ClientResponse
 
 if TYPE_CHECKING:  # pragma: no cover
-    from .typedefs import Protocol
     from .client import ClientSession
+    from .typedefs import Protocol
 
     _ParamT_contra = TypeVar("_ParamT_contra", contravariant=True)
 

From e402da0e1a5e45d1ddd87ebc43e8a6a63c229f66 Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Mon, 4 Jan 2021 18:24:02 +0000
Subject: [PATCH 06/10] Lint.

---
 aiohttp/typedefs.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/aiohttp/typedefs.py b/aiohttp/typedefs.py
index b550e85942e..f42e343ff07 100644
--- a/aiohttp/typedefs.py
+++ b/aiohttp/typedefs.py
@@ -7,10 +7,11 @@
 from multidict import CIMultiDict, CIMultiDictProxy, MultiDict, MultiDictProxy, istr
 from yarl import URL
 
+# These are for other modules to use (to avoid repeating the conditional import).
 if sys.version_info >= (3, 8):
-    from typing import Final, Protocol, TypedDict
+    from typing import Final, Protocol, TypedDict  # noqa: F401
 else:
-    from typing_extensions import Final, Protocol, TypedDict
+    from typing_extensions import Final, Protocol, TypedDict  # noqa: F401
 
 DEFAULT_JSON_ENCODER = json.dumps
 DEFAULT_JSON_DECODER = json.loads

From 0a3ba8e9438535e89885fa1624205a50cd379e30 Mon Sep 17 00:00:00 2001
From: Sam Bull <aa6bs0@sambull.org>
Date: Mon, 4 Jan 2021 18:33:18 +0000
Subject: [PATCH 07/10] Update typedefs.py

---
 aiohttp/typedefs.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aiohttp/typedefs.py b/aiohttp/typedefs.py
index f42e343ff07..9f552b1bcc2 100644
--- a/aiohttp/typedefs.py
+++ b/aiohttp/typedefs.py
@@ -9,7 +9,7 @@
 
 # These are for other modules to use (to avoid repeating the conditional import).
 if sys.version_info >= (3, 8):
-    from typing import Final, Protocol, TypedDict  # noqa: F401
+    from typing import Final, Protocol, TypedDict
 else:
     from typing_extensions import Final, Protocol, TypedDict  # noqa: F401
 

From 2eab9bbd57fdc114aa2ba0a1e3823fc2f6b581ae Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Mon, 4 Jan 2021 18:42:40 +0000
Subject: [PATCH 08/10] Revert hdrs.py

---
 aiohttp/hdrs.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/aiohttp/hdrs.py b/aiohttp/hdrs.py
index e1896d60429..a619f2543e4 100644
--- a/aiohttp/hdrs.py
+++ b/aiohttp/hdrs.py
@@ -2,11 +2,15 @@
 
 # After changing the file content call ./tools/gen.py
 # to regenerate the headers parser
+import sys
 from typing import Set
 
 from multidict import istr
 
-from .typedefs import Final
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
+    from typing_extensions import Final
 
 METH_ANY: Final[str] = "*"
 METH_CONNECT: Final[str] = "CONNECT"

From a08357cb2272cf8a350640d19fba1fbccf64a330 Mon Sep 17 00:00:00 2001
From: Sam Bull <git@sambull.org>
Date: Sun, 14 Mar 2021 18:24:34 +0000
Subject: [PATCH 09/10] Fix typing.

---
 aiohttp/typedefs.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/aiohttp/typedefs.py b/aiohttp/typedefs.py
index 9f552b1bcc2..916895a6d6c 100644
--- a/aiohttp/typedefs.py
+++ b/aiohttp/typedefs.py
@@ -9,9 +9,9 @@
 
 # These are for other modules to use (to avoid repeating the conditional import).
 if sys.version_info >= (3, 8):
-    from typing import Final, Protocol, TypedDict
+    from typing import Final as Final, Protocol as Protocol, TypedDict as TypedDict
 else:
-    from typing_extensions import Final, Protocol, TypedDict  # noqa: F401
+    from typing_extensions import Final, Protocol as Protocol, TypedDict as TypedDict  # noqa: F401
 
 DEFAULT_JSON_ENCODER = json.dumps
 DEFAULT_JSON_DECODER = json.loads

From ff09e432ec4c4037b634eff69ec067186ab81b15 Mon Sep 17 00:00:00 2001
From: Sam Bull <aa6bs0@sambull.org>
Date: Sun, 14 Mar 2021 18:27:51 +0000
Subject: [PATCH 10/10] Line wrap

---
 aiohttp/typedefs.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/aiohttp/typedefs.py b/aiohttp/typedefs.py
index 916895a6d6c..0e5051910e5 100644
--- a/aiohttp/typedefs.py
+++ b/aiohttp/typedefs.py
@@ -11,7 +11,11 @@
 if sys.version_info >= (3, 8):
     from typing import Final as Final, Protocol as Protocol, TypedDict as TypedDict
 else:
-    from typing_extensions import Final, Protocol as Protocol, TypedDict as TypedDict  # noqa: F401
+    from typing_extensions import (  # noqa: F401
+        Final,
+        Protocol as Protocol,
+        TypedDict as TypedDict,
+    )
 
 DEFAULT_JSON_ENCODER = json.dumps
 DEFAULT_JSON_DECODER = json.loads