Add __setattr__ to logging.LogRecord (#8064)

stdlib/logging/__init__.pyi

@@ -413,6 +413,8 @@ class LogRecord:
         sinfo: str | None = ...,
     ) -> None: ...
     def getMessage(self) -> str: ...
+    # Allows setting contextual information on LogRecord objects as per the docs, see #7833
+    def __setattr__(self, __name: str, __value: Any) -> None: ...
 
 _L = TypeVar("_L", bound=Logger | LoggerAdapter[Any])
 

test_cases/stdlib/test_logging.py

@@ -0,0 +1,16 @@
+import logging
+from typing import Any
+
+# This pattern comes from the logging docs, and should therefore pass a type checker
+# See https://docs.python.org/3/library/logging.html#logrecord-objects
+
+old_factory = logging.getLogRecordFactory()
+
+
+def record_factory(*args: Any, **kwargs: Any) -> logging.LogRecord:
+    record = old_factory(*args, **kwargs)
+    record.custom_attribute = 0xDECAFBAD
+    return record
+
+
+logging.setLogRecordFactory(record_factory)