Patch task for Python>=3.7 again, reverts #57, fixes #64

nest_asyncio.py

@@ -176,6 +176,17 @@ def _check_running(self):
 
 def _patch_task():
     """Patch the Task's step and enter/leave methods to make it reentrant."""
+
+    def step(task, exc=None):
+        curr_task = curr_tasks.get(task._loop)
+        try:
+            step_orig(task, exc)
+        finally:
+            if curr_task is None:
+                curr_tasks.pop(task._loop, None)
+            else:
+                curr_tasks[task._loop] = curr_task
+
     Task = asyncio.Task
     if sys.version_info >= (3, 7, 0):
 
@@ -188,18 +199,9 @@ def leave_task(loop, task):
         asyncio.tasks._enter_task = enter_task
         asyncio.tasks._leave_task = leave_task
         curr_tasks = asyncio.tasks._current_tasks
+        step_orig = Task._Task__step
+        Task._Task__step = step
     else:
-
-        def step(task, exc=None):
-            curr_task = curr_tasks.get(task._loop)
-            try:
-                step_orig(task, exc)
-            finally:
-                if curr_task is None:
-                    curr_tasks.pop(task._loop, None)
-                else:
-                    curr_tasks[task._loop] = curr_task
-
         curr_tasks = Task._current_tasks
         step_orig = Task._step
         Task._step = step