--- a/sat/plugins/plugin_xep_0280.py	Wed Jun 27 07:51:29 2018 +0200
+++ b/sat/plugins/plugin_xep_0280.py	Wed Jun 27 20:14:46 2018 +0200
@@ -19,6 +19,7 @@
 
 from sat.core.i18n import _, D_
 from sat.core.log import getLogger
+
 log = getLogger(__name__)
 from sat.core import exceptions
 from sat.core.constants import Const as C
@@ -27,6 +28,7 @@
 from twisted.internet import defer
 from wokkel import disco, iwokkel
 from zope.interface import implements
+
 try:
     from twisted.words.protocols.xmlstream import XMPPHandler
 except ImportError:
@@ -36,7 +38,7 @@
 PARAM_CATEGORY = "Misc"
 PARAM_NAME = "carbon"
 PARAM_LABEL = D_(u"Message carbons")
-NS_CARBONS = 'urn:xmpp:carbons:2'
+NS_CARBONS = "urn:xmpp:carbons:2"
 
 PLUGIN_INFO = {
     C.PI_NAME: u"XEP-0280 Plugin",
@@ -46,12 +48,12 @@
     C.PI_DEPENDENCIES: [],
     C.PI_MAIN: u"XEP_0280",
     C.PI_HANDLER: u"yes",
-    C.PI_DESCRIPTION: D_(u"""Implementation of Message Carbons""")
+    C.PI_DESCRIPTION: D_(u"""Implementation of Message Carbons"""),
 }
 
 
 class XEP_0280(object):
-    # TODO: param is only checked at profile connection
+    #  TODO: param is only checked at profile connection
     #       activate carbons on param change even after profile connection
     # TODO: chat state notifications are not handled yet (and potentially other XEPs?)
 
@@ -64,11 +66,11 @@
     </individual>
     </params>
     """.format(
-        category_name = PARAM_CATEGORY,
-        category_label = D_(PARAM_CATEGORY),
-        param_name = PARAM_NAME,
-        param_label = PARAM_LABEL,
-        )
+        category_name=PARAM_CATEGORY,
+        category_label=D_(PARAM_CATEGORY),
+        param_name=PARAM_NAME,
+        param_label=PARAM_LABEL,
+    )
 
     def __init__(self, host):
         log.info(_("Plugin XEP_0280 initialization"))
@@ -86,15 +88,17 @@
         (in particular end 2 end encryption plugins)
         @param message_elt(domish.Element): <message> stanza
         """
-        if message_elt.name != u'message':
+        if message_elt.name != u"message":
             log.error(u"addPrivateElt must be used with <message> stanzas")
             return
-        message_elt.addElement((NS_CARBONS, u'private'))
+        message_elt.addElement((NS_CARBONS, u"private"))
 
     @defer.inlineCallbacks
     def profileConnected(self, client):
         """activate message carbons on connection if possible and activated in config"""
-        activate = self.host.memory.getParamA(PARAM_NAME, PARAM_CATEGORY, profile_key=client.profile)
+        activate = self.host.memory.getParamA(
+            PARAM_NAME, PARAM_CATEGORY, profile_key=client.profile
+        )
         if not activate:
             log.info(_(u"Not activating message carbons as requested in params"))
             return
@@ -105,7 +109,7 @@
         else:
             log.info(_(u"message carbons available, enabling it"))
             iq_elt = client.IQ()
-            iq_elt.addElement((NS_CARBONS, 'enable'))
+            iq_elt.addElement((NS_CARBONS, "enable"))
             try:
                 yield iq_elt.send()
             except StanzaError as e:
@@ -126,40 +130,45 @@
             # we continue normal behaviour
             return True
 
-        if message_elt['from'] != client.jid.userhost():
-            log.warning(u"The message carbon received is not from our server, hack attempt?\n{xml}".format(
-                xml = message_elt.toXml(),
-                ))
+        if message_elt["from"] != client.jid.userhost():
+            log.warning(
+                u"The message carbon received is not from our server, hack attempt?\n{xml}".format(
+                    xml=message_elt.toXml()
+                )
+            )
             return
-        forwarded_elt = next(carbons_elt.elements(C.NS_FORWARD, 'forwarded'))
-        cc_message_elt = next(forwarded_elt.elements(C.NS_CLIENT, 'message'))
-        if carbons_elt.name == 'received':
+        forwarded_elt = next(carbons_elt.elements(C.NS_FORWARD, "forwarded"))
+        cc_message_elt = next(forwarded_elt.elements(C.NS_CLIENT, "message"))
+        if carbons_elt.name == "received":
             # on receive we replace the wrapping message with the CCed one
             # and continue the normal behaviour
-            message_elt['from'] = cc_message_elt['from']
+            message_elt["from"] = cc_message_elt["from"]
             del message_elt.children[:]
             for c in cc_message_elt.children:
                 message_elt.addChild(c)
             return True
-        elif carbons_elt.name == 'sent':
+        elif carbons_elt.name == "sent":
             # on send we parse the message and just add it to history
             # and send it to frontends (without normal sending treatments)
             mess_data = SatMessageProtocol.parseMessage(cc_message_elt, client)
-            if not mess_data['message'] and not mess_data['subject']:
+            if not mess_data["message"] and not mess_data["subject"]:
                 return False
             client.messageAddToHistory(mess_data)
             client.messageSendToBridge(mess_data)
         else:
-            log.warning(u"invalid message carbons received:\n{xml}".format(
-                xml = message_elt.toXml()))
+            log.warning(
+                u"invalid message carbons received:\n{xml}".format(
+                    xml=message_elt.toXml()
+                )
+            )
         return False
 
 
 class XEP_0280_handler(XMPPHandler):
     implements(iwokkel.IDisco)
 
-    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
         return [disco.DiscoFeature(NS_CARBONS)]
 
-    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
+    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
         return []