--- a/sat_pubsub/pubsub_admin.py	Fri Aug 16 12:48:34 2019 +0200
+++ b/sat_pubsub/pubsub_admin.py	Fri Aug 16 12:53:33 2019 +0200
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 #-*- coding: utf-8 -*-
 
 # Copyright (c) 2019 Jérôme Poisson
@@ -21,7 +21,7 @@
 
 """
 
-from zope.interface import implements
+from zope.interface import implementer
 from twisted.python import log
 from twisted.internet import defer
 from twisted.words.protocols.jabber import jid, error as jabber_error, xmlstream
@@ -29,12 +29,12 @@
 from wokkel.subprotocols import XMPPHandler
 from wokkel import disco, iwokkel, pubsub
 
-NS_PUBSUB_ADMIN = u"https://salut-a-toi.org/spec/pubsub_admin:0"
+NS_PUBSUB_ADMIN = "https://salut-a-toi.org/spec/pubsub_admin:0"
 ADMIN_REQUEST = '/iq[@type="set"]/admin[@xmlns="{}"]'.format(NS_PUBSUB_ADMIN)
 
 
+@implementer(iwokkel.IDisco)
 class PubsubAdminHandler(XMPPHandler):
-    implements(iwokkel.IDisco)
 
     def __init__(self, backend):
         super(PubsubAdminHandler, self).__init__()
@@ -43,7 +43,7 @@
     def connectionInitialized(self):
         self.xmlstream.addObserver(ADMIN_REQUEST, self.onAdminRequest)
 
-    def sendError(self, iq_elt, condition=u'bad-request'):
+    def sendError(self, iq_elt, condition='bad-request'):
         stanza_error = jabber_error.StanzaError(condition)
         iq_error = stanza_error.toResponse(iq_elt)
         self.parent.xmlstream.send(iq_error)
@@ -58,42 +58,42 @@
             pep = False
 
         # is the sender really an admin?
-        admins = self.backend.config[u'admins_jids_list']
-        from_jid = jid.JID(iq_elt[u'from'])
+        admins = self.backend.config['admins_jids_list']
+        from_jid = jid.JID(iq_elt['from'])
         if from_jid.userhostJID() not in admins:
             log.msg("WARNING: admin request done by non admin entity {from_jid}"
                 .format(from_jid=from_jid.full()))
-            self.sendError(iq_elt, u'forbidden')
+            self.sendError(iq_elt, 'forbidden')
             return
 
         # alright, we can proceed
-        recipient = jid.JID(iq_elt[u'to'])
+        recipient = jid.JID(iq_elt['to'])
         admin_elt = iq_elt.admin
         try:
-            pubsub_elt = next(admin_elt.elements(pubsub.NS_PUBSUB, u'pubsub'))
-            publish_elt = next(pubsub_elt.elements(pubsub.NS_PUBSUB, u'publish'))
+            pubsub_elt = next(admin_elt.elements(pubsub.NS_PUBSUB, 'pubsub'))
+            publish_elt = next(pubsub_elt.elements(pubsub.NS_PUBSUB, 'publish'))
         except StopIteration:
             self.sendError(iq_elt)
             return
         try:
-            node = publish_elt[u'node']
+            node = publish_elt['node']
         except KeyError:
             self.sendError(iq_elt)
             return
 
         # we prepare the result IQ request, we will fill it with item ids
-        iq_result_elt = xmlstream.toResponse(iq_elt, u'result')
-        result_admin_elt = iq_result_elt.addElement((NS_PUBSUB_ADMIN, u'admin'))
-        result_pubsub_elt = result_admin_elt.addElement((pubsub.NS_PUBSUB, u'pubsub'))
-        result_publish_elt = result_pubsub_elt.addElement(u'publish')
-        result_publish_elt[u'node'] = node
+        iq_result_elt = xmlstream.toResponse(iq_elt, 'result')
+        result_admin_elt = iq_result_elt.addElement((NS_PUBSUB_ADMIN, 'admin'))
+        result_pubsub_elt = result_admin_elt.addElement((pubsub.NS_PUBSUB, 'pubsub'))
+        result_publish_elt = result_pubsub_elt.addElement('publish')
+        result_publish_elt['node'] = node
 
         # now we can send the items
-        for item in publish_elt.elements(pubsub.NS_PUBSUB, u'item'):
+        for item in publish_elt.elements(pubsub.NS_PUBSUB, 'item'):
             try:
-                requestor = jid.JID(item.attributes.pop(u'publisher'))
+                requestor = jid.JID(item.attributes.pop('publisher'))
             except Exception as e:
-                log.msg(u"WARNING: invalid jid in publisher ({requestor}): {msg}"
+                log.msg("WARNING: invalid jid in publisher ({requestor}): {msg}"
                     .format(requestor=requestor, msg=e))
                 self.sendError(iq_elt)
                 return
@@ -111,20 +111,20 @@
                     recipient=recipient)
             except (error.Forbidden, error.ItemForbidden):
                 __import__('pudb').set_trace()
-                self.sendError(iq_elt, u"forbidden")
+                self.sendError(iq_elt, "forbidden")
                 return
             except Exception as e:
-                self.sendError(iq_elt, u"internal-server-error")
-                log.msg(u"INTERNAL ERROR: {msg}".format(msg=e))
+                self.sendError(iq_elt, "internal-server-error")
+                log.msg("INTERNAL ERROR: {msg}".format(msg=e))
                 return
 
-            result_item_elt = result_publish_elt.addElement(u'item')
+            result_item_elt = result_publish_elt.addElement('item')
             # either the id was given and it is available in item
             # either it's a new item, and we can retrieve it from return payload
             try:
-                result_item_elt[u'id'] = item[u'id']
+                result_item_elt['id'] = item['id']
             except KeyError:
-                result_item_elt = payload.publish.item[u'id']
+                result_item_elt = payload.publish.item['id']
 
         self.xmlstream.send(iq_result_elt)