All commands should pass comm errors up

rtsp_url, storage_all, storage_used, storage_used_percent & storage_total caught comm errors. They should be passed up to let app deal with them.

src/amcrest/special.py

@@ -63,7 +63,7 @@ def rtsp_url(self, channelno=None, typeno=None):
         try:
             port = ':' + [x.split('=')[1] for x in self.rtsp_config.split()
                           if x.startswith('table.RTSP.Port=')][0]
-        except (AmcrestError, IndexError):
+        except IndexError:
             port = ''
         return 'rtsp://{}:{}@{}{}/{}'.format(
             self._user, self._password, self._host, port, cmd)

src/amcrest/storage.py

@@ -43,12 +43,7 @@ def storage_device_names(self):
         return ret.content.decode('utf-8')
 
     def _get_storage_values(self, *params):
-        try:
-            info = self.storage_device_info
-        except AmcrestError:
-            if len(params) == 1:
-                return None
-            return [None for i in range(len(params))]
+        info = self.storage_device_info
         ret = []
         for param in params:
             try: