v2.34.2

---------

Co-authored-by: Nate Prewitt <nate.prewitt@gmail.com>

HISTORY.md

@@ -6,6 +6,28 @@ dev
 
 - \[Short description of non-trivial change.\]
 
+
+2.34.2 (2026-05-14)
+-------------------
+- Moved `headers` input type back to `Mapping` to avoid invariance issues
+  with `MutableMapping` and inferred dict types. Users calling
+  `Request.headers.update()` may need to narrow typing in their code. (#7441)
+
+
+2.34.1 (2026-05-13)
+-------------------
+
+**Bugfixes**
+- Widened `json` input type from `dict` and `list` to `Mapping`
+  and `Sequence`. (#7436)
+- Changed `headers` input type to MutableMapping and removed `None` from
+  `Request.headers` typing to improve handling for users. (#7431)
+- `Response.reason` moved from `str | None` to `str` to improve handling
+  for users. (#7437)
+- Fixed a bug where some bodies with custom `__getattr__` implementations
+  weren't being properly detected as Iterables. (#7433)
+
+
 2.34.0 (2026-05-11)
 -------------------
 

src/requests/__version__.py

@@ -5,8 +5,8 @@
 __title__ = "requests"
 __description__ = "Python HTTP for Humans."
 __url__ = "https://requests.readthedocs.io"
-__version__ = "2.34.0"
-__build__ = 0x023400
+__version__ = "2.34.2"
+__build__ = 0x023402
 __author__ = "Kenneth Reitz"
 __author_email__ = "me@kennethreitz.org"
 __license__ = "Apache-2.0"

src/requests/_types.py

@@ -9,7 +9,7 @@ by external code.
 
 from __future__ import annotations
 
-from collections.abc import Callable, Iterable, Mapping, MutableMapping
+from collections.abc import Callable, Iterable, Mapping, MutableMapping, Sequence
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -109,8 +109,7 @@ if TYPE_CHECKING:
         bytes | str | Iterable[bytes | str] | SupportsRead[bytes | str] | None
     )
 
-    HeadersType: TypeAlias = CaseInsensitiveDict[str] | Mapping[str, str | bytes]
-    HeadersUpdateType: TypeAlias = Mapping[str, str | bytes | None]
+    HeadersType: TypeAlias = Mapping[str, str | bytes] | None
 
     CookiesType: TypeAlias = RequestsCookieJar | Mapping[str, str]
 
@@ -139,13 +138,19 @@ if TYPE_CHECKING:
     VerifyType: TypeAlias = bool | str
     CertType: TypeAlias = str | tuple[str, str] | None
     JsonType: TypeAlias = (
-        None | bool | int | float | str | list["JsonType"] | dict[str, "JsonType"]
+        None
+        | bool
+        | int
+        | float
+        | str
+        | Sequence["JsonType"]
+        | Mapping[str, "JsonType"]
     )
 
     # TypedDicts for Unpack kwargs (PEP 692)
 
     class BaseRequestKwargs(TypedDict, total=False):
-        headers: Mapping[str, str | bytes] | None
+        headers: HeadersType
         cookies: RequestsCookieJar | CookieJar | dict[str, str] | None
         files: FilesType
         auth: AuthType

src/requests/models.py

@@ -310,7 +310,7 @@ class Request(RequestHooksMixin):
 
     method: str | None
     url: _t.UriType | None
-    headers: CaseInsensitiveDict[str] | Mapping[str, str | bytes] | None
+    headers: Mapping[str, str | bytes]
     files: _t.FilesType
     data: _t.DataType
     json: _t.JsonType
@@ -322,7 +322,7 @@ class Request(RequestHooksMixin):
         self,
         method: str | None = None,
         url: _t.UriType | None = None,
-        headers: Mapping[str, str | bytes] | None = None,
+        headers: _t.HeadersType = None,
         files: _t.FilesType = None,
         data: _t.DataType = None,
         params: _t.ParamsType = None,
@@ -596,9 +596,9 @@ class PreparedRequest(RequestEncodingMixin, RequestHooksMixin):
             if not isinstance(body, bytes):
                 body = body.encode("utf-8")
 
-        if isinstance(data, Iterable) and not isinstance(
-            data, (str, bytes, list, tuple, Mapping)
-        ):
+        # data that proxies attributes to underlying objects needs hasattr
+        is_iterable = isinstance(data, Iterable) or hasattr(data, "__iter__")
+        if is_iterable and not isinstance(data, (str, bytes, list, tuple, Mapping)):
             try:
                 length = super_len(data)
             except (TypeError, AttributeError, UnsupportedOperation):
@@ -741,7 +741,7 @@ class Response:
     url: str
     encoding: str | None
     history: list[Response]
-    reason: str | None
+    reason: str
     cookies: RequestsCookieJar
     elapsed: datetime.timedelta
     request: PreparedRequest
@@ -790,7 +790,7 @@ class Response:
         self.history = []
 
         #: Textual reason of responded HTTP Status, e.g. "Not Found" or "OK".
-        self.reason = None
+        self.reason = None  # type: ignore[assignment]
 
         #: A CookieJar of Cookies the server sent back.
         self.cookies = cookiejar_from_dict({})

src/requests/sessions.py

@@ -560,7 +560,7 @@ class Session(SessionRedirectMixin):
         url: _t.UriType,
         params: _t.ParamsType = None,
         data: _t.DataType = None,
-        headers: Mapping[str, str | bytes] | None = None,
+        headers: _t.HeadersType = None,
         cookies: RequestsCookieJar | CookieJar | dict[str, str] | None = None,
         files: _t.FilesType = None,
         auth: _t.AuthType = None,

tests/test_requests.py

@@ -2073,6 +2073,21 @@ class TestRequests:
 
         assert "Unable to rewind request body" in str(e)
 
+    def test_getattr_proxy_stream_follows_redirect(self, httpbin):
+        """Ensure stream wrappers that don't implement __iter__ directly are still detected."""
+
+        class AttrProxy:
+            def __init__(self):
+                self._file = io.BytesIO(b"data")
+
+            def __getattr__(self, name):
+                return getattr(self._file, name)
+
+        r = requests.post(
+            httpbin("redirect-to?url=/post&status_code=307"), data=AttrProxy()
+        )
+        assert r.json()["data"] == "data"
+
     def _patch_adapter_gzipped_redirect(self, session, url):
         adapter = session.get_adapter(url=url)
         org_build_response = adapter.build_response