zhangyangyu · Feb 27, 2017 · Feb 22, 2017 · Feb 27, 2017 · Feb 27, 2017
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
@@ -170,6 +170,9 @@ def f(mutex):
         mutex.acquire()
         self.assertIn(tid, threading._active)
         self.assertIsInstance(threading._active[tid], threading._DummyThread)
+        #Issue 29376
+        self.assertTrue(threading._active[tid].is_alive())
+        self.assertRegex(repr(threading._active[tid]), '_DummyThread')
         del threading._active[tid]
 
     # PyThreadState_SetAsyncExc() is a CPython-only gimmick, not (currently)

diff --git a/Lib/threading.py b/Lib/threading.py
@@ -1217,6 +1217,10 @@ def __init__(self):
     def _stop(self):
         pass
 
+    def is_alive(self):
+        assert not self._is_stopped and self._started.is_set()
+        return True
+
     def join(self, timeout=None):
         assert False, "cannot join a dummy thread"
 

diff --git a/Misc/NEWS b/Misc/NEWS
@@ -239,6 +239,8 @@ Extension Modules
 Library
 -------
 
+- bpo-29376: Fix assertion error in threading._DummyThread.is_alive().
+
 - bpo-29532: Altering a kwarg dictionary passed to functools.partial()
   no longer affects a partial object after creation.
-Original file line number
+Diff line change
@@ Expand Up / @@ -239,6 +239,8 @@ Extension Modules @@
     Library
     -------
+    - bpo-29376: Fix assertion error in threading._DummyThread.is_alive().
     - bpo-29532: Altering a kwarg dictionary passed to functools.partial()
       no longer affects a partial object after creation.
@@ Expand Down @@