gh-154205: threading: Deprecated items to be removed in 3.21.

Doc/deprecations/pending-removal-in-3.21.rst

@@ -28,3 +28,13 @@ Pending removal in Python 3.21
 
   * ``tempfile._TemporaryFileWrapper`` will be removed in Python 3.21. Use the
     public :class:`tempfile.TemporaryFileWrapper` instead.
+
+* :mod:`threading`:
+
+  * ``threading.Condition.notifyAll``, ``threading.Event.isSet``,  and
+    ``threading.activeCount`` will be removed in Python 3.21. Use the snake case
+    names (e.g., ``notify_all``) instead.
+  * ``threading.Thread.isDaemon``, ``threading.Thread.setDaemon`` will be removed
+    in Python 3.21. Use the property ``threading.Thread.daemon`` instead.
+  * ``threading.Thread.getName`` and ``threading.Thread.setName`` will be removed
+    in Python 3.21. Use the property ``threading.Thread.name`` instead.

Doc/whatsnew/3.16.rst

@@ -720,6 +720,16 @@ New deprecations
     Use the new public :class:`tempfile.TemporaryFileWrapper` instead,
     which is the return type of :func:`tempfile.NamedTemporaryFile`.
 
+* :mod:`threading`:
+
+  * ``threading.Condition.notifyAll``, ``threading.Event.isSet``,  and
+    ``threading.activeCount`` will be removed in Python 3.21. Use the snake case
+    names (e.g., ``notify_all``) instead.
+  * ``threading.Thread.isDaemon``, ``threading.Thread.setDaemon`` will be removed
+    in Python 3.21. Use the property ``threading.Thread.daemon`` instead.
+  * ``threading.Thread.getName`` and ``threading.Thread.setName`` will be removed
+    in Python 3.21. Use the property ``threading.Thread.name`` instead.
+
 * :mod:`tkinter`:
 
   * :func:`tkinter.filedialog.askopenfiles` is deprecated and slated for

Lib/threading.py

@@ -4,6 +4,7 @@
 import sys as _sys
 import _thread
 import _contextvars
+lazy import warnings
 
 from time import monotonic as _time
 from _weakrefset import WeakSet
@@ -444,9 +445,7 @@ def notifyAll(self):
         This method is deprecated, use notify_all() instead.
 
         """
-        import warnings
-        warnings.warn('notifyAll() is deprecated, use notify_all() instead',
-                      DeprecationWarning, stacklevel=2)
+        warnings._deprecated("notifyAll", 'notifyAll() is deprecated, use notify_all() instead', remove=(3, 21))
         self.notify_all()
 
 
@@ -616,9 +615,7 @@ def isSet(self):
         This method is deprecated, use is_set() instead.
 
         """
-        import warnings
-        warnings.warn('isSet() is deprecated, use is_set() instead',
-                      DeprecationWarning, stacklevel=2)
+        warnings._deprecated("isSet", 'isSet() is deprecated, use is_set() instead', remove=(3, 21))
         return self.is_set()
 
     def set(self):
@@ -1352,9 +1349,7 @@ def isDaemon(self):
         This method is deprecated, use the daemon attribute instead.
 
         """
-        import warnings
-        warnings.warn('isDaemon() is deprecated, get the daemon attribute instead',
-                      DeprecationWarning, stacklevel=2)
+        warnings._deprecated('isDaemon', 'isDaemon() is deprecated, get the daemon attribute instead',remove=(3,21))
         return self.daemon
 
     def setDaemon(self, daemonic):
@@ -1363,9 +1358,7 @@ def setDaemon(self, daemonic):
         This method is deprecated, use the .daemon property instead.
 
         """
-        import warnings
-        warnings.warn('setDaemon() is deprecated, set the daemon attribute instead',
-                      DeprecationWarning, stacklevel=2)
+        warnings._deprecated('setDaemon', 'setDaemon() is deprecated, set the daemon attribute instead', remove=(3,21))
         self.daemon = daemonic
 
     def getName(self):
@@ -1374,9 +1367,7 @@ def getName(self):
         This method is deprecated, use the name attribute instead.
 
         """
-        import warnings
-        warnings.warn('getName() is deprecated, get the name attribute instead',
-                      DeprecationWarning, stacklevel=2)
+        warnings._deprecated('getName', 'getName() is deprecated, get the name attribute instead', remove=(3,21))
         return self.name
 
     def setName(self, name):
@@ -1385,9 +1376,7 @@ def setName(self, name):
         This method is deprecated, use the name attribute instead.
 
         """
-        import warnings
-        warnings.warn('setName() is deprecated, set the name attribute instead',
-                      DeprecationWarning, stacklevel=2)
+        warnings._deprecated('setName', 'setName() is deprecated, set the name attribute instead', remove=(3,21))
         self.name = name
 
 
@@ -1621,9 +1610,7 @@ def currentThread():
     This function is deprecated, use current_thread() instead.
 
     """
-    import warnings
-    warnings.warn('currentThread() is deprecated, use current_thread() instead',
-                  DeprecationWarning, stacklevel=2)
+    warnings._deprecated('currentThread', 'currentThread() is deprecated, use current_thread() instead', remove=(3,21))
     return current_thread()
 
 def active_count():
@@ -1644,9 +1631,7 @@ def activeCount():
     This function is deprecated, use active_count() instead.
 
     """
-    import warnings
-    warnings.warn('activeCount() is deprecated, use active_count() instead',
-                  DeprecationWarning, stacklevel=2)
+    warnings._deprecated('activeCount', 'activeCount() is deprecated, use active_count() instead', remove=(3,21))
     return active_count()
 
 def _enumerate():

Misc/NEWS.d/next/Library/2026-07-19-17-39-08.gh-issue-154205.B9rNEh.rst

@@ -0,0 +1,5 @@
+The methods ``threading.Condition.notifyAll``, ``threading.Event.isSet``,
+``threading.Thread.isDaemon``, ``threading.Thread.setDaemon``,
+``threading.Thread.getName``, ``threading.Thread.setName``, and the function
+``threading.activeCount``, which have been deprecated since Python 3.10, are
+now scheduled for removal in Python 3.21.