rename states to more sensible names; make idle not useless

Author: Golf Player

nbclient/client.py

@@ -34,8 +34,8 @@ def timestamp():
 
 
 class ExecutionState(enum.Enum):
-    NOTHING = 0
-    STARTUP = 1
+    IDLE = 0
+    STARTING_UP = 1
     STARTING_KERNEL_CLIENT = 2
     EXECUTING = 3
     CLEANING_UP = 4
@@ -323,7 +323,7 @@ def reset_execution_trackers(self):
         self.output_hook_stack = collections.defaultdict(list)
         # our front-end mimicing Output widgets
         self.comm_objects = {}
-        self.state_history = []
+        self.state_history = [ExecutionState.IDLE, timestamp()]
         self.current_cell = None
         self.current_cell_index = -1
 
@@ -518,7 +518,7 @@ async def async_execute(self, reset_kc=False, **kwargs):
         if reset_kc and self.km:
             await self._async_cleanup_kernel()
         self.reset_execution_trackers()
-        self._update_state(ExecutionState.STARTUP)
+        self._update_state(ExecutionState.STARTING_UP)
 
         async with self.async_setup_kernel(**kwargs):
             self._update_state(ExecutionState.EXECUTING)