--- a/sat/plugins/plugin_xep_0264.py	Wed Jun 27 07:51:29 2018 +0200
+++ b/sat/plugins/plugin_xep_0264.py	Wed Jun 27 20:14:46 2018 +0200
@@ -21,6 +21,7 @@
 from sat.core.i18n import _
 from sat.core.constants import Const as C
 from sat.core.log import getLogger
+
 log = getLogger(__name__)
 from twisted.internet import threads
 from twisted.python.failure import Failure
@@ -31,13 +32,17 @@
 
 from sat.core import exceptions
 import hashlib
+
 try:
     from PIL import Image
 except:
-    raise exceptions.MissingModule(u"Missing module pillow, please download/install it from https://python-pillow.github.io")
+    raise exceptions.MissingModule(
+        u"Missing module pillow, please download/install it from https://python-pillow.github.io"
+    )
 
-# cf. https://stackoverflow.com/a/23575424
+#  cf. https://stackoverflow.com/a/23575424
 from PIL import ImageFile
+
 ImageFile.LOAD_TRUNCATED_IMAGES = True
 
 try:
@@ -46,10 +51,10 @@
     from wokkel.subprotocols import XMPPHandler
 
 
-MIME_TYPE = u'image/jpeg'
-SAVE_FORMAT = u'JPEG' # (cf. Pillow documentation)
+MIME_TYPE = u"image/jpeg"
+SAVE_FORMAT = u"JPEG"  # (cf. Pillow documentation)
 
-NS_THUMBS = 'urn:xmpp:thumbs:1'
+NS_THUMBS = "urn:xmpp:thumbs:1"
 
 PLUGIN_INFO = {
     C.PI_NAME: "XEP-0264",
@@ -60,7 +65,7 @@
     C.PI_DEPENDENCIES: ["XEP-0234"],
     C.PI_MAIN: "XEP_0264",
     C.PI_HANDLER: "yes",
-    C.PI_DESCRIPTION: _("""Thumbnails handling""")
+    C.PI_DESCRIPTION: _("""Thumbnails handling"""),
 }
 
 
@@ -81,39 +86,39 @@
 
     def _addFileThumbnails(self, file_elt, extra_args):
         try:
-            thumbnails = extra_args[u'extra'][C.KEY_THUMBNAILS]
+            thumbnails = extra_args[u"extra"][C.KEY_THUMBNAILS]
         except KeyError:
             return
         for thumbnail in thumbnails:
-            thumbnail_elt = file_elt.addElement((NS_THUMBS, u'thumbnail'))
-            thumbnail_elt['uri'] = u'cid:' + thumbnail['id']
-            thumbnail_elt['media-type'] = MIME_TYPE
-            width, height = thumbnail['size']
-            thumbnail_elt['width'] = unicode(width)
-            thumbnail_elt['height'] = unicode(height)
+            thumbnail_elt = file_elt.addElement((NS_THUMBS, u"thumbnail"))
+            thumbnail_elt["uri"] = u"cid:" + thumbnail["id"]
+            thumbnail_elt["media-type"] = MIME_TYPE
+            width, height = thumbnail["size"]
+            thumbnail_elt["width"] = unicode(width)
+            thumbnail_elt["height"] = unicode(height)
         return True
 
     def _getFileThumbnails(self, file_elt, file_data):
         thumbnails = []
-        for thumbnail_elt in file_elt.elements(NS_THUMBS, u'thumbnail'):
-            uri = thumbnail_elt['uri']
-            if uri.startswith ('cid:'):
-                thumbnail = {'id': uri[4:]}
-            width = thumbnail_elt.getAttribute('width')
-            height = thumbnail_elt.getAttribute('height')
+        for thumbnail_elt in file_elt.elements(NS_THUMBS, u"thumbnail"):
+            uri = thumbnail_elt["uri"]
+            if uri.startswith("cid:"):
+                thumbnail = {"id": uri[4:]}
+            width = thumbnail_elt.getAttribute("width")
+            height = thumbnail_elt.getAttribute("height")
             if width and height:
                 try:
-                    thumbnail['size'] = int(width), int(height)
+                    thumbnail["size"] = int(width), int(height)
                 except ValueError:
                     pass
             try:
-                thumbnail['mime_type'] = thumbnail_elt['media-type']
+                thumbnail["mime_type"] = thumbnail_elt["media-type"]
             except KeyError:
                 pass
             thumbnails.append(thumbnail)
 
         if thumbnails:
-            file_data.setdefault('extra', {})[C.KEY_THUMBNAILS] = thumbnails
+            file_data.setdefault("extra", {})[C.KEY_THUMBNAILS] = thumbnails
         return True
 
     ## thumbnails generation ##
@@ -145,11 +150,8 @@
         uid = self.getThumbId(image_uid or source_path, size)
 
         with self.host.common_cache.cacheData(
-            PLUGIN_INFO[C.PI_IMPORT_NAME],
-            uid,
-            MIME_TYPE,
-            max_age,
-            ) as f:
+            PLUGIN_INFO[C.PI_IMPORT_NAME], uid, MIME_TYPE, max_age
+        ) as f:
             img.save(f, SAVE_FORMAT)
 
         return img.size, uid
@@ -171,17 +173,19 @@
         """
 
         d = threads.deferToThread(
-                self._blockingGenThumb, source_path, size, max_age, image_uid=image_uid)
-        d.addErrback(lambda failure_:
-            log.error(u"thumbnail generation error: {}".format(failure_)))
+            self._blockingGenThumb, source_path, size, max_age, image_uid=image_uid
+        )
+        d.addErrback(
+            lambda failure_: log.error(u"thumbnail generation error: {}".format(failure_))
+        )
         return d
 
 
 class XEP_0264_handler(XMPPHandler):
     implements(iwokkel.IDisco)
 
-    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
         return [disco.DiscoFeature(NS_THUMBS)]
 
-    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
+    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
         return []