Make filename, stream, and handlers parameters of logging.basicConfig mutually-exclusive (#15435)

stdlib/@tests/test_cases/check_logging.py

@@ -28,3 +28,27 @@ logging.handlers.QueueHandler(multiprocessing.Queue())
 logging.handlers.QueueListener(queue.Queue())
 logging.handlers.QueueListener(queue.SimpleQueue())
 logging.handlers.QueueListener(multiprocessing.Queue())
+
+# These all raise at runtime.
+logging.basicConfig(filename="foo.log", handlers=[])  # type: ignore
+logging.basicConfig(filemode="w", handlers=[])  # type: ignore
+logging.basicConfig(stream=None, handlers=[])  # type: ignore
+logging.basicConfig(filename="foo.log", stream=None)  # type: ignore
+logging.basicConfig(filename=None, stream=None)  # type: ignore
+# These are ok.
+logging.basicConfig()
+logging.basicConfig(handlers=[])
+logging.basicConfig(filename="foo.log", filemode="w")
+logging.basicConfig(filename="foo.log", filemode="w", handlers=None)
+logging.basicConfig(stream=None)
+logging.basicConfig(stream=None, handlers=None)
+# dubious but accepted, has same meaning as 'stream=None'.
+logging.basicConfig(filename=None)
+# These are technically accepted at runtime, but are forbidden in the stubs to help
+# prevent user mistakes. Passing 'filemode' / 'encoding' / 'errors' does nothing
+# if 'filename' is not specified.
+logging.basicConfig(stream=None, filemode="w")  # type: ignore
+logging.basicConfig(stream=None, encoding="utf-8")  # type: ignore
+logging.basicConfig(stream=None, errors="strict")  # type: ignore
+logging.basicConfig(handlers=[], encoding="utf-8")  # type: ignore
+logging.basicConfig(handlers=[], errors="strict")  # type: ignore

stdlib/logging/__init__.pyi

@@ -576,20 +576,41 @@ if sys.version_info >= (3, 11):
     def getLevelNamesMapping() -> dict[str, int]: ...
 
 def makeLogRecord(dict: Mapping[str, object]) -> LogRecord: ...
+@overload  # handlers is non-None
 def basicConfig(
     *,
-    filename: StrPath | None = None,
+    format: str = ...,  # default value depends on the value of `style`
+    datefmt: str | None = None,
+    style: _FormatStyle = "%",
+    level: _Level | None = None,
+    handlers: Iterable[Handler],
+    force: bool | None = False,
+) -> None: ...
+@overload  # handlers is None, filename is passed (but possibly None)
+def basicConfig(
+    *,
+    filename: StrPath | None,
     filemode: str = "a",
     format: str = ...,  # default value depends on the value of `style`
     datefmt: str | None = None,
     style: _FormatStyle = "%",
     level: _Level | None = None,
-    stream: SupportsWrite[str] | None = None,
-    handlers: Iterable[Handler] | None = None,
+    handlers: None = None,
     force: bool | None = False,
     encoding: str | None = None,
     errors: str | None = "backslashreplace",
 ) -> None: ...
+@overload  # handlers is None, filename is not passed
+def basicConfig(
+    *,
+    format: str = ...,  # default value depends on the value of `style`
+    datefmt: str | None = None,
+    style: _FormatStyle = "%",
+    level: _Level | None = None,
+    stream: SupportsWrite[str] | None = None,
+    handlers: None = None,
+    force: bool | None = False,
+) -> None: ...
 def shutdown(handlerList: Sequence[Any] = ...) -> None: ...  # handlerList is undocumented
 def setLoggerClass(klass: type[Logger]) -> None: ...
 def captureWarnings(capture: bool) -> None: ...