Add hasattr checks for remaining protocol isinstance checks

Author: nateprewitt

src/requests/models.py

@@ -161,7 +161,7 @@ def _encode_params(
 
         if isinstance(data, (str, bytes)):
             return data
-        elif isinstance(data, _SupportsRead):
+        elif isinstance(data, _SupportsRead) or hasattr(data, "read"):
             return data
         elif hasattr(data, "__iter__"):
             result: list[tuple[bytes, bytes]] = []
@@ -641,7 +641,8 @@ def prepare_body(
             else:
                 if raw_data:
                     body = self._encode_params(raw_data)
-                    if isinstance(data, basestring) or isinstance(data, _SupportsRead):
+                    has_read = isinstance(data, _SupportsRead) or hasattr(data, "read")
+                    if isinstance(data, basestring) or has_read:
                         content_type = None
                     else:
                         content_type = "application/x-www-form-urlencoded"

tests/test_requests.py

@@ -1098,6 +1098,21 @@ def test_post_named_tempfile(self, httpbin):
         assert r.status_code == 200
         assert r.json()["files"]["file"] == "named temp file contents\n"
 
+    def test_post_getattr_proxy_read_only(self, httpbin):
+
+        class ReadProxy:
+            def __init__(self):
+                self._file = io.BytesIO(b"streamed body")
+
+            def __getattr__(self, name):
+                if name == "__iter__":
+                    raise AttributeError(name)
+                return getattr(self._file, name)
+
+        r = requests.post(httpbin("post"), data=ReadProxy())
+        assert r.status_code == 200
+        assert r.json()["data"] == "streamed body"
+
     @pytest.mark.parametrize(
         "data",
         (