Fix typing in the FirmwareUpdateChecker plugin.

plugins/FirmwareUpdateChecker/FirmwareUpdateChecker.py

@@ -1,10 +1,12 @@
 # Copyright (c) 2017 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
-import json, os
+import os
 from PyQt5.QtCore import QUrl
 from PyQt5.QtGui import QDesktopServices
 
+from typing import List
+
 from UM.Extension import Extension
 from UM.Application import Application
 from UM.Logger import Logger
@@ -19,12 +21,13 @@ from .FirmwareUpdateCheckerLookup import FirmwareUpdateCheckerLookup, get_settin
 
 i18n_catalog = i18nCatalog("cura")
 
+
 ## This Extension checks for new versions of the firmware based on the latest checked version number.
 #  The plugin is currently only usable for applications maintained by Ultimaker. But it should be relatively easy
 #  to change it to work for other applications.
 class FirmwareUpdateChecker(Extension):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
 
         # Listen to a Signal that indicates a change in the list of printers, just if the user has enabled the
@@ -36,7 +39,8 @@ class FirmwareUpdateChecker(Extension):
         self._late_init = True  # Init some things after creation, since we need the path from the plugin-mgr.
         self._download_url = None
         self._check_job = None
-        self._name_cache = []
+        self._name_cache = []  # type: List[str]
+        self._lookups = None
 
     ##  Callback for the message that is spawned when there is a new version.
     def _onActionTriggered(self, message, action):
@@ -46,8 +50,8 @@ class FirmwareUpdateChecker(Extension):
                 QDesktopServices.openUrl(QUrl(download_url))
             else:
                 Logger.log('e', "Can't find URL for {0}".format(action))
-        except:
-            Logger.log('e', "Don't know what to do with {0}".format(action))
+        except Exception as ex:
+            Logger.log('e', "Don't know what to do with '{0}' because {1}".format(action, ex))
 
     def _onContainerAdded(self, container):
         # Only take care when a new GlobalStack was added