Add float() operator to templates

homeassistant/helpers/template.py

@@ -52,6 +52,7 @@ def render(hass, template, variables=None, **kwargs):
         return ENV.from_string(template, {
             'closest': location_methods.closest,
             'distance': location_methods.distance,
+            'float': forgiving_float,
             'is_state': hass.states.is_state,
             'is_state_attr': hass.states.is_state_attr,
             'now': dt_util.as_local(utcnow),
@@ -240,6 +241,14 @@ def multiply(value, amount):
         return value
 
 
+def forgiving_float(value):
+    """Try to convert value to a float."""
+    try:
+        return float(value)
+    except (ValueError, TypeError):
+        return value
+
+
 class TemplateEnvironment(ImmutableSandboxedEnvironment):
     """Home Assistant template environment."""
 

tests/helpers/test_template.py

@@ -51,6 +51,21 @@ class TestUtilTemplate(unittest.TestCase):
 {% for state in states.sensor %}{{ state.state }}{% endfor %}
                 """))
 
+    def test_float(self):
+        self.hass.states.set('sensor.temperature', '12')
+
+        self.assertEqual(
+            '12.0',
+            template.render(
+                self.hass,
+                '{{ float(states.sensor.temperature.state) }}'))
+
+        self.assertEqual(
+            'True',
+            template.render(
+                self.hass,
+                '{{ float(states.sensor.temperature.state) > 11 }}'))
+
     def test_rounding_value(self):
         self.hass.states.set('sensor.temperature', 12.78)