processed first round of feedback, plus extra's

- ruff formatting
- docstrings
- variable names
- type annotations
- don't return ret = startup() which is annotated to return None
- moved time sleep intervals to singular global, for clarity

bittensor/axon.py

@@ -63,6 +63,12 @@
 from bittensor.utils import networking
 
 
+"""
+The quantum of time to sleep in waiting loops, in seconds.
+"""
+TIME_SLEEP_INTERVAL: float = 1e-3
+
+
 class FastAPIThreadedServer(uvicorn.Server):
     """
     The ``FastAPIThreadedServer`` class is a specialized server implementation for the Axon server in the Bittensor network.
@@ -109,27 +115,36 @@ class FastAPIThreadedServer(uvicorn.Server):
     _thread: threading.Thread = None
     _started: bool = False
 
-    def set_exception(self, ex):
+    def set_exception(self, exception: Exception) -> None:
+        """
+        Set self._exception in a thread safe manner, so the worker thread can communicate exceptions to the main thread.
+        """
         with self._lock:
-            self._exception = ex
+            self._exception = exception
 
-    def get_exception(self):
+    def get_exception(self) -> Optional[Exception]:
         with self._lock:
             return self._exception
 
-    def set_thread(self, thread):
+    def set_thread(self, thread: threading.Thread):
+        """
+        Set self._thread in a thread safe manner, so the main thread can get the worker thread object.
+        """
         with self._lock:
             self._thread = thread
 
-    def get_thread(self):
+    def get_thread(self) -> Optional[threading.Thread]:
         with self._lock:
             return self._thread
 
-    def set_started(self, started):
+    def set_started(self, started: bool) -> None:
+        """
+        Set self._started in a thread safe manner, so the main thread can get the worker thread status.
+        """
         with self._lock:
             self._started = started
 
-    def get_started(self):
+    def get_started(self) -> bool:
         with self._lock:
             return self._started
 
@@ -143,9 +158,8 @@ async def startup(self, sockets: Optional[List[socket.socket]] = None) -> None:
         """
         Adds a thread-safe call to set a 'started' flag on the object.
         """
-        ret = await super().startup(sockets)
+        await super().startup(sockets)
         self.set_started(True)
-        return ret
 
     @contextlib.contextmanager
     def run_in_thread(self):
@@ -161,9 +175,9 @@ def run_in_thread(self):
         thread = threading.Thread(target=self.run, daemon=True)
         thread.start()
         try:
-            t0 = time.time()
-            while not self.get_started() and time.time()-t0<1:
-                time.sleep(1e-3)
+            time_start = time.time()
+            while not self.get_started() and time.time() - time_start < 1:
+                time.sleep(TIME_SLEEP_INTERVAL)
             if not self.get_started():
                 raise Exception("failed to start server")
             yield thread
@@ -181,7 +195,7 @@ def _wrapper_run(self):
                 while not self.should_exit:
                     if not thread.is_alive():
                         raise Exception("worker thread died")
-                    time.sleep(1e-3)
+                    time.sleep(TIME_SLEEP_INTERVAL)
         except Exception as e:
             self.set_exception(e)
 
@@ -458,23 +472,25 @@ def info(self) -> "bittensor.AxonInfo":
             placeholder2=0,
         )
 
-    # Our instantiator should be able to test axon.exception to see if any
-    # exception occurred.
     @property
-    def exception(self):
+    def exception(self) -> Optional[Exception]:
+        """
+        Axon objects expose exceptions that occurred internally through the .exception property.
+        """
         # for future use: setting self._exception to signal an exception
-        e = getattr(self,'_exception',None)
-        if e:
-            return e
+        exception = getattr(self, "_exception", None)
+        if exception:
+            return exception
         return self.fast_server.get_exception()
 
-    # Our instantiator should be able to test axon.is_running() to see if all
-    # required threads etc are running.
-    def is_running(self):
-        t = self.fast_server.get_thread()
-        if t is None:
+    def is_running(self) -> bool:
+        """
+        Axon objects can be queried using .is_running() to test whether worker threads are running.
+        """
+        thread = self.fast_server.get_thread()
+        if thread is None:
             return False
-        return t.is_alive()
+        return thread.is_alive()
 
     def attach(
         self,