Handle errors in storage methods

Address problem noted in home-assistant/core#19982. Fix will also require an update to HA amcrest component to bump the version requirement of this package.

src/amcrest/storage.py

@@ -10,7 +10,8 @@
 # GNU General Public License for more details.
 #
 # vim:sw=4:ts=4:et
-from amcrest.utils import to_unit, percent
+from .exceptions import AmcrestError
+from .utils import to_unit, percent, pretty
 
 
 class Storage(object):
@@ -29,26 +30,26 @@ def storage_device_names(self):
         )
         return ret.content.decode('utf-8')
 
-    @property
-    def storage_used(self, dev='/dev/mmc0', unit='GB'):
-        ret = self.storage_device_info
-
-        # pylint: disable=fixme
-        # TODO
-        # Use regex to enhance the filter
-        status = [s for s in ret.split() if '.UsedBytes=' in s][0]
-        return to_unit(status.split('=')[-1], unit)
+    def _extract_storage_value(self, param, unit):
+        try:
+            return to_unit(
+                pretty([part for part in self.storage_device_info.split()
+                        if '.{}='.format(param) in part][0]),
+                unit)
+        except (AmcrestError, AttributeError, IndexError):
+            return 'unknown', 'GB'
 
     @property
-    def storage_total(self, dev='/dev/mmc0', unit='GB'):
-        ret = self.storage_device_info
+    def storage_used(self):
+        return self._extract_storage_value('UsedBytes', 'GB')
 
-        # pylint: disable=fixme
-        # TODO
-        # Use regex to enhance the filter
-        status = [s for s in ret.split() if '.TotalBytes=' in s][0]
-        return to_unit(status.split('=')[-1], unit)
+    @property
+    def storage_total(self):
+        return self._extract_storage_value('TotalBytes', 'GB')
 
     @property
     def storage_used_percent(self):
-        return percent(self.storage_used[0], self.storage_total[0])
+        try:
+            return percent(self.storage_used[0], self.storage_total[0])
+        except (ValueError, ZeroDivisionError):
+            return 'unknown'

src/amcrest/utils.py

@@ -35,8 +35,7 @@ def pretty(value, delimiter='='):
 
 def percent(part, whole):
     """Convert data to percent"""
-    result = 100 * float(part) / float(whole)
-    return float('{:.{prec}f}'.format(result, prec=PRECISION))
+    return round(100 * float(part) / float(whole), PRECISION)
 
 
 def str2bool(value):
@@ -64,7 +63,7 @@ def to_unit(value, unit='B'):
 
     if unit in byte_array:
         result = value / 1024**byte_array.index(unit)
-        return (float('{:.{prec}f}'.format(result, prec=PRECISION)), unit)
+        return round(result, PRECISION), unit
 
     return value
 

src/amcrest/video.py

@@ -132,7 +132,7 @@ def video_in_options(self):
     def video_in_option(self, param, profile='Day'):
         """
         Return video input option.
-        
+
         Params:
             param - parameter, such as 'DayNightColor'
             profile - 'Day', 'Night' or 'Normal'
@@ -160,7 +160,7 @@ def set_video_in_option(self, param, value, profile='Day'):
     def day_night_color(self):
         """
         Return Day & Night Color Mode for Day profile.
-        
+
         Result is 0: always multicolor
                   1: autoswitch along with brightness
                   2: always monochrome