Minor improvements

[osm/N2VC.git] / juju / model.py

diff --git a/juju/model.py b/juju/model.py
index 621ae06..7897d42 100644 (file)
--- a/juju/model.py
+++ b/juju/model.py
@@ -207,18 +207,16 @@ class ModelEntity(object):
         self.connected = connected
         self.connection = model.connection
 
+    def __repr__(self):
+        return '<{} entity_id="{}">'.format(type(self).__name__,
+                                            self.entity_id)
+
     def __getattr__(self, name):
         """Fetch object attributes from the underlying data dict held in the
         model.
 
         """
-        if self.data is None:
-            raise DeadEntityException(
-                "Entity {}:{} is dead - its attributes can no longer be "
-                "accessed. Use the .previous() method on this object to get "
-                "a copy of the object at its previous state.".format(
-                    self.entity_type, self.entity_id))
-        return self.data[name]
+        return self.safe_data[name]
 
     def __bool__(self):
         return bool(self.data)
@@ -285,6 +283,22 @@ class ModelEntity(object):
         return self.model.state.entity_data(
             self.entity_type, self.entity_id, self._history_index)
 
+    @property
+    def safe_data(self):
+        """The data dictionary for this entity.
+
+        If this `ModelEntity` points to the dead state, it will
+        raise `DeadEntityException`.
+
+        """
+        if self.data is None:
+            raise DeadEntityException(
+                "Entity {}:{} is dead - its attributes can no longer be "
+                "accessed. Use the .previous() method on this object to get "
+                "a copy of the object at its previous state.".format(
+                    self.entity_type, self.entity_id))
+        return self.data
+
     def previous(self):
         """Return a copy of this object as was at its previous state in
         history.
@@ -425,13 +439,13 @@ class Model(object):
             lambda: len(self.machines) == 0
         )
 
-    async def block_until(self, *conditions, timeout=None):
+    async def block_until(self, *conditions, timeout=None, wait_period=0.5):
         """Return only after all conditions are true.
 
         """
         async def _block():
             while not all(c() for c in conditions):
-                await asyncio.sleep(0)
+                await asyncio.sleep(wait_period)
         await asyncio.wait_for(_block(), timeout)
 
     @property