Have logbook only report each sensor every 15 minutes

homeassistant/components/logbook.py

@@ -5,6 +5,7 @@ homeassistant.components.logbook
 Parses events and generates a human log
 """
 from datetime import datetime
+from itertools import groupby
 
 from homeassistant import State, DOMAIN as HA_DOMAIN
 from homeassistant.const import (
@@ -25,6 +26,8 @@ QUERY_EVENTS_BETWEEN = """
     ORDER BY time_fired
 """
 
+GROUP_BY_MINUTES = 15
+
 
 def setup(hass, config):
     """ Listens for download events to download files. """
@@ -72,9 +75,34 @@ class Entry(object):
 
 
 def humanify(events):
-    """ Generator that converts a list of events into Entry objects. """
+    """
+    Generator that converts a list of events into Entry objects.
+
+    Will try to group events if possible:
+     - if 2+ sensor updates in GROUP_BY_MINUTES, show last
+    """
     # pylint: disable=too-many-branches
-    for event in events:
+
+    # Group events in batches of GROUP_BY_MINUTES
+    for _, g_events in groupby(
+            events,
+            lambda event: event.time_fired.minute // GROUP_BY_MINUTES):
+
+        events_batch = list(g_events)
+
+        # Keep track of last sensor states
+        last_sensor_event = {}
+
+        # Process events
+        for event in events_batch:
+            if event.event_type == EVENT_STATE_CHANGED:
+                entity_id = event.data['entity_id']
+
+                if entity_id.startswith('sensor.'):
+                    last_sensor_event[entity_id] = event
+
+        # Yield entries
+        for event in events_batch:
             if event.event_type == EVENT_STATE_CHANGED:
 
                 # Do not report on new entities
@@ -88,6 +116,11 @@ def humanify(events):
 
                 domain = to_state.domain
 
+                # Skip all but the last sensor state
+                if domain == 'sensor' and \
+                   event != last_sensor_event[to_state.entity_id]:
+                    continue
+
                 entry = Entry(
                     event.time_fired, domain=domain,
                     name=to_state.name, entity_id=to_state.entity_id)