bpo-36492: Deprecate passing some arguments as keyword arguments. (GH-12637)
Deprecated passing the following arguments as keyword arguments:
- "func" in functools.partialmethod(), weakref.finalize(),
profile.Profile.runcall(), cProfile.Profile.runcall(),
bdb.Bdb.runcall(), trace.Trace.runfunc() and
curses.wrapper().
- "function" in unittest.addModuleCleanup() and
unittest.TestCase.addCleanup().
- "fn" in the submit() method of concurrent.futures.ThreadPoolExecutor
and concurrent.futures.ProcessPoolExecutor.
- "callback" in contextlib.ExitStack.callback(),
contextlib.AsyncExitStack.callback() and
contextlib.AsyncExitStack.push_async_callback().
- "c" and "typeid" in the create() method of multiprocessing.managers.Server
and multiprocessing.managers.SharedMemoryServer.
- "obj" in weakref.finalize().
Also allowed to pass arbitrary keyword arguments (even "self" and "func")
if the above arguments are passed as positional argument.
diff --git a/Lib/contextlib.py b/Lib/contextlib.py
index c06ec73..ae498a2 100644
--- a/Lib/contextlib.py
+++ b/Lib/contextlib.py
@@ -377,7 +377,8 @@
return MethodType(cm_exit, cm)
@staticmethod
- def _create_cb_wrapper(callback, *args, **kwds):
+ def _create_cb_wrapper(*args, **kwds):
+ callback, *args = args
def _exit_wrapper(exc_type, exc, tb):
callback(*args, **kwds)
return _exit_wrapper
@@ -426,11 +427,26 @@
self._push_cm_exit(cm, _exit)
return result
- def callback(self, callback, *args, **kwds):
+ def callback(*args, **kwds):
"""Registers an arbitrary callback and arguments.
Cannot suppress exceptions.
"""
+ if len(args) >= 2:
+ self, callback, *args = args
+ elif not args:
+ raise TypeError("descriptor 'callback' of '_BaseExitStack' object "
+ "needs an argument")
+ elif 'callback' in kwds:
+ callback = kwds.pop('callback')
+ self, *args = args
+ import warnings
+ warnings.warn("Passing 'callback' as keyword argument is deprecated",
+ DeprecationWarning, stacklevel=2)
+ else:
+ raise TypeError('callback expected at least 1 positional argument, '
+ 'got %d' % (len(args)-1))
+
_exit_wrapper = self._create_cb_wrapper(callback, *args, **kwds)
# We changed the signature, so using @wraps is not appropriate, but
@@ -536,7 +552,8 @@
return MethodType(cm_exit, cm)
@staticmethod
- def _create_async_cb_wrapper(callback, *args, **kwds):
+ def _create_async_cb_wrapper(*args, **kwds):
+ callback, *args = args
async def _exit_wrapper(exc_type, exc, tb):
await callback(*args, **kwds)
return _exit_wrapper
@@ -571,11 +588,26 @@
self._push_async_cm_exit(exit, exit_method)
return exit # Allow use as a decorator
- def push_async_callback(self, callback, *args, **kwds):
+ def push_async_callback(*args, **kwds):
"""Registers an arbitrary coroutine function and arguments.
Cannot suppress exceptions.
"""
+ if len(args) >= 2:
+ self, callback, *args = args
+ elif not args:
+ raise TypeError("descriptor 'push_async_callback' of "
+ "'AsyncExitStack' object needs an argument")
+ elif 'callback' in kwds:
+ callback = kwds.pop('callback')
+ self, *args = args
+ import warnings
+ warnings.warn("Passing 'callback' as keyword argument is deprecated",
+ DeprecationWarning, stacklevel=2)
+ else:
+ raise TypeError('push_async_callback expected at least 1 '
+ 'positional argument, got %d' % (len(args)-1))
+
_exit_wrapper = self._create_async_cb_wrapper(callback, *args, **kwds)
# We changed the signature, so using @wraps is not appropriate, but