Adding range filter

homeassistant/components/sensor/filter.py

@@ -28,6 +28,7 @@
 
 _LOGGER = logging.getLogger(__name__)
 
+FILTER_NAME_RANGE = 'range'
 FILTER_NAME_LOWPASS = 'lowpass'
 FILTER_NAME_OUTLIER = 'outlier'
 FILTER_NAME_THROTTLE = 'throttle'
@@ -40,6 +41,8 @@
 CONF_FILTER_PRECISION = 'precision'
 CONF_FILTER_RADIUS = 'radius'
 CONF_FILTER_TIME_CONSTANT = 'time_constant'
+CONF_FILTER_LOWER_BOUND = 'lower_bound'
+CONF_FILTER_UPPER_BOUND = 'upper_bound'
 CONF_TIME_SMA_TYPE = 'type'
 
 TIME_SMA_LAST = 'last'
@@ -77,6 +80,12 @@
                  default=DEFAULT_FILTER_TIME_CONSTANT): vol.Coerce(int),
 })
 
+FILTER_RANGE_SCHEMA = FILTER_SCHEMA.extend({
+    vol.Required(CONF_FILTER_NAME): FILTER_NAME_RANGE,
+    vol.Optional(CONF_FILTER_LOWER_BOUND): vol.Coerce(float),
+    vol.Optional(CONF_FILTER_UPPER_BOUND): vol.Coerce(float),
+})
+
 FILTER_TIME_SMA_SCHEMA = FILTER_SCHEMA.extend({
     vol.Required(CONF_FILTER_NAME): FILTER_NAME_TIME_SMA,
     vol.Optional(CONF_TIME_SMA_TYPE,
@@ -100,7 +109,8 @@
                                         [vol.Any(FILTER_OUTLIER_SCHEMA,
                                                  FILTER_LOWPASS_SCHEMA,
                                                  FILTER_TIME_SMA_SCHEMA,
-                                                 FILTER_THROTTLE_SCHEMA)])
+                                                 FILTER_THROTTLE_SCHEMA,
+                                                 FILTER_RANGE_SCHEMA)])
 })
 
 
@@ -325,6 +335,49 @@ def filter_state(self, new_state):
         return new_state
 
 
+@FILTERS.register(FILTER_NAME_RANGE)
+class RangeFilter(Filter):
+    """Range filter.
+
+    Determines if new state is in the range of upper_bound and lower_bound.
+    If not inside, lower or upper bound is returned instead.
+
+    Args:
+        upper_bound (float): band upper bound
+        lower_bound (float): band lower bound
+    """
+
+    def __init__(self, entity,
+                 lower_bound=None, upper_bound=None):
+        """Initialize Filter."""
+        super().__init__(FILTER_NAME_RANGE, entity=entity)
+        self._lower_bound = lower_bound
+        self._upper_bound = upper_bound
+        self._stats_internal = Counter()
+
+    def _filter_state(self, new_state):
+        """Implement the range filter."""
+        if self._upper_bound and new_state.state > self._upper_bound:
+
+            self._stats_internal['erasures_up'] += 1
+
+            _LOGGER.debug("Upper outlier nr. %s in %s: %s",
+                          self._stats_internal['erasures_up'],
+                          self._entity, new_state)
+            new_state.state = self._upper_bound
+
+        elif self._lower_bound and new_state.state < self._lower_bound:
+
+            self._stats_internal['erasures_low'] += 1
+
+            _LOGGER.debug("Lower outlier nr. %s in %s: %s",
+                          self._stats_internal['erasures_low'],
+                          self._entity, new_state)
+            new_state.state = self._lower_bound
+
+        return new_state
+
+
 @FILTERS.register(FILTER_NAME_OUTLIER)
 class OutlierFilter(Filter):
     """BASIC outlier filter.

tests/components/sensor/test_filter.py

@@ -4,7 +4,8 @@
 from unittest.mock import patch
 
 from homeassistant.components.sensor.filter import (
-    LowPassFilter, OutlierFilter, ThrottleFilter, TimeSMAFilter)
+    LowPassFilter, OutlierFilter, ThrottleFilter, TimeSMAFilter,
+    RangeFilter)
 import homeassistant.util.dt as dt_util
 from homeassistant.setup import setup_component
 import homeassistant.core as ha
@@ -131,6 +132,23 @@ def test_lowpass(self):
             filtered = filt.filter_state(state)
         self.assertEqual(18.05, filtered.state)
 
+    def test_range(self):
+        """Test if range filter works."""
+        lower = 10
+        upper = 20
+        filt = RangeFilter(entity=None,
+                           lower_bound=lower,
+                           upper_bound=upper)
+        for unf_state in self.values:
+            unf = float(unf_state.state)
+            filtered = filt.filter_state(unf_state)
+            if unf < lower:
+                self.assertEqual(lower, filtered.state)
+            elif unf > upper:
+                self.assertEqual(upper, filtered.state)
+            else:
+                self.assertEqual(unf, filtered.state)
+
     def test_throttle(self):
         """Test if lowpass filter works."""
         filt = ThrottleFilter(window_size=3,