--- a/sat_pubsub/pgsql_storage.py	Fri Aug 16 12:48:34 2019 +0200
+++ b/sat_pubsub/pgsql_storage.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) 2012-2019 Jérôme Poisson
@@ -53,7 +53,7 @@
 
 import copy, logging
 
-from zope.interface import implements
+from zope.interface import implementer
 
 from twisted.internet import reactor
 from twisted.internet import defer
@@ -77,7 +77,7 @@
 
 # parseXml manage str, but we get unicode
 parseXml = lambda unicode_data: generic.parseXml(unicode_data.encode('utf-8'))
-ITEMS_SEQ_NAME = u'node_{node_id}_seq'
+ITEMS_SEQ_NAME = 'node_{node_id}_seq'
 PEP_COL_NAME = 'pep'
 CURRENT_VERSION = '5'
 # retrieve the maximum integer item id + 1
@@ -102,9 +102,9 @@
     return "{} {}".format(query, pep_check), values
 
 
+@implementer(iidavoll.IStorage)
 class Storage:
 
-    implements(iidavoll.IStorage)
 
     defaultConfig = {
             'leaf': {
@@ -435,7 +435,7 @@
         if node_accesses != ('open',) or item_accesses != ('open',):
             raise NotImplementedError('only "open" access model is handled for now')
         if not pep:
-            raise NotImplementedError(u"getLastItems is only implemented for PEP at the moment")
+            raise NotImplementedError("getLastItems is only implemented for PEP at the moment")
         d = self.dbpool.runQuery("""SELECT DISTINCT ON (node_id) pep, node, data::text, items.access_model
                                     FROM items
                                     NATURAL JOIN nodes
@@ -452,9 +452,9 @@
         return d
 
 
+@implementer(iidavoll.INode)
 class Node:
 
-    implements(iidavoll.INode)
 
     def __init__(self, nodeDbId, nodeIdentifier, config, schema):
         self.nodeDbId = nodeDbId
@@ -488,10 +488,10 @@
         if self._config[const.OPT_SERIAL_IDS]:
             d = self.dbpool.runQuery("SELECT nextval('{seq_name}')".format(
                 seq_name = ITEMS_SEQ_NAME.format(node_id=self.nodeDbId)))
-            d.addCallback(lambda rows: unicode(rows[0][0]))
+            d.addCallback(lambda rows: str(rows[0][0]))
             return d
         else:
-            return defer.succeed(unicode(uuid.uuid4()))
+            return defer.succeed(str(uuid.uuid4()))
 
     @staticmethod
     def _configurationTriggers(cursor, node_id, old_config, new_config):
@@ -645,7 +645,7 @@
 
         subscriptions = []
         for row in rows:
-            subscriber = jid.JID(u'%s/%s' % (row.jid, row.resource))
+            subscriber = jid.JID('%s/%s' % (row.jid, row.resource))
 
             options = {}
             if row.subscription_type:
@@ -730,7 +730,7 @@
         values = []
         for subscription in subscriptions:
             entity_id = entities_map[subscription.subscriber].entity_id
-            resource = subscription.subscriber.resource or u''
+            resource = subscription.subscriber.resource or ''
             values.append((self.nodeDbId, entity_id, resource, subscription.state, None, None))
         # we use upsert so new values are inserted and existing one updated. This feature is only available for PostgreSQL >= 9.5
         cursor.execute("INSERT INTO subscriptions(node_id, entity_id, resource, state, subscription_type, subscription_depth) VALUES " + placeholders + " ON CONFLICT (entity_id, resource, node_id) DO UPDATE SET state=EXCLUDED.state", [v for v in values])
@@ -808,7 +808,8 @@
         # then we construct values for affiliations update according to entity_id we just got
         placeholders = ','.join(len(affiliations) * ["(%s,%s,%s)"])
         values = []
-        map(values.extend, ((e.entity_id, affiliations[jid.JID(e.jid)], self.nodeDbId) for e in entities))
+        for e in entities:
+            values.extend((e.entity_id, affiliations[jid.JID(e.jid)], self.nodeDbId))
 
         # we use upsert so new values are inserted and existing one updated. This feature is only available for PostgreSQL >= 9.5
         cursor.execute("INSERT INTO affiliations(entity_id,affiliation,node_id) VALUES " + placeholders + " ON CONFLICT  (entity_id,node_id) DO UPDATE SET affiliation=EXCLUDED.affiliation", values)
@@ -836,9 +837,9 @@
         return [row[0] for row in rows]
 
 
+@implementer(iidavoll.ILeafNode)
 class LeafNode(Node):
 
-    implements(iidavoll.ILeafNode)
 
     nodeType = 'leaf'
 
@@ -851,7 +852,7 @@
         """
         keys = ext_data.get('order_by')
         if not keys:
-            return u'ORDER BY updated ' + direction
+            return 'ORDER BY updated ' + direction
         cols_statmnt = []
         for key in keys:
             if key == 'creation':
@@ -859,11 +860,11 @@
             elif key == 'modification':
                 column = 'updated'
             else:
-                log.msg(u"WARNING: Unknown order by key: {key}".format(key=key))
+                log.msg("WARNING: Unknown order by key: {key}".format(key=key))
                 column = 'updated'
-            cols_statmnt.append(column + u' ' + direction)
+            cols_statmnt.append(column + ' ' + direction)
 
-        return u"ORDER BY " + u",".join([col for col in cols_statmnt])
+        return "ORDER BY " + ",".join([col for col in cols_statmnt])
 
     @defer.inlineCallbacks
     def storeItems(self, items_data, publisher):
@@ -918,10 +919,10 @@
                     cursor.execute(NEXT_ITEM_ID_QUERY.format(node_id=self.nodeDbId))
                     next_id = cursor.fetchone()[0]
                     # we update the sequence, so we can skip conflicting ids
-                    cursor.execute(u"SELECT setval('{seq_name}', %s)".format(
+                    cursor.execute("SELECT setval('{seq_name}', %s)".format(
                         seq_name = ITEMS_SEQ_NAME.format(node_id=self.nodeDbId)), [next_id])
                     # and now we can retry the query with the new id
-                    item['id'] = insert_data[1] = unicode(next_id)
+                    item['id'] = insert_data[1] = str(next_id)
                     # item saved in DB must also be updated with the new id
                     insert_data[3] = item.toXml()
                     cursor.execute(insert_query, insert_data)
@@ -1059,7 +1060,7 @@
                         args.append(filter_.value)
                     else:
                         query_filters.append("AND publisher LIKE %s")
-                        args.append(u"{}%".format(filter_.value))
+                        args.append("{}%".format(filter_.value))
                 elif filter_.var == const.MAM_FILTER_CATEGORY:
                     query.append("LEFT JOIN item_categories USING (item_id)")
                     query_filters.append("AND category=%s")