diff --git a/setup.py b/setup.py
index 523921b..9393ca8 100644
--- a/setup.py
+++ b/setup.py
@@ -1,15 +1,14 @@
 #! /usr/bin/env python
-# -*- coding: utf-8 -*-
 
 import os
 import subprocess
 import sys
-
-from setuptools.command.install_lib import install_lib as _install_lib
+from distutils.cmd import Command
 from distutils.command.build import build as _build
 from distutils.command.sdist import sdist
-from distutils.cmd import Command
-from setuptools import setup, find_packages
+
+from setuptools import find_packages, setup
+from setuptools.command.install_lib import install_lib as _install_lib
 
 
 class eo_sdist(sdist):
@@ -29,7 +28,7 @@ def get_version():
     tag exists, take 0.0- and add the length of the commit log.
     """
     if os.path.exists('VERSION'):
-        with open('VERSION', 'r') as v:
+        with open('VERSION') as v:
             return v.read()
     if os.path.exists('.git'):
         p = subprocess.Popen(
diff --git a/tests/conftest.py b/tests/conftest.py
index 0e38d8b..664cda5 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -14,8 +14,8 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import pytest
 import django_webtest
+import pytest
 
 
 @pytest.fixture
diff --git a/tests/test_contacts_manager.py b/tests/test_contacts_manager.py
index db8e8c2..5ccc7d5 100644
--- a/tests/test_contacts_manager.py
+++ b/tests/test_contacts_manager.py
@@ -14,11 +14,11 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+from unittest import mock
+
 import httmock
-import mock
 import pytest
 import requests
-
 from django.contrib.contenttypes.models import ContentType
 from django.core.files.base import ContentFile
 
diff --git a/tests/test_mail_command.py b/tests/test_mail_command.py
index 35aa43e..65a5e7e 100644
--- a/tests/test_mail_command.py
+++ b/tests/test_mail_command.py
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import pytest
-
 from django.core.management import call_command
 from django.core.management.base import CommandError
 
diff --git a/tests/test_mail_manager.py b/tests/test_mail_manager.py
index d4b04c9..265aa32 100644
--- a/tests/test_mail_manager.py
+++ b/tests/test_mail_manager.py
@@ -14,14 +14,14 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import httmock
 import json
-import requests
-from webtest import Upload
 
+import httmock
+import requests
 from django.contrib.contenttypes.models import ContentType
 from django.core.files.base import ContentFile
 from django.utils.encoding import force_text
+from webtest import Upload
 
 from welco.sources.mail.models import Mail
 
diff --git a/tests/test_manager.py b/tests/test_manager.py
index b760643..1200dce 100644
--- a/tests/test_manager.py
+++ b/tests/test_manager.py
@@ -14,10 +14,10 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import httmock
-import mock
-import pytest
+from unittest import mock
 
+import httmock
+import pytest
 from django.contrib.contenttypes.models import ContentType
 from django.core.files.base import ContentFile
 
@@ -201,7 +201,7 @@ def test_menu_json_view(app, user, mail_group, phone_group, counter_group, kb_gr
     app.set_user(user.username)
     resp = app.get('/menu.json', status=200)
     assert resp.content_type == 'application/json'
-    assert sorted([x['label'] for x in resp.json]) == ['Call Center', 'Counter', 'Knowledge Base', 'Mails']
+    assert sorted(x['label'] for x in resp.json) == ['Call Center', 'Counter', 'Knowledge Base', 'Mails']
 
     resp = app.get('/menu.json?callback=foo', status=200)
     assert resp.content_type == 'application/javascript'
diff --git a/tests/test_qualification.py b/tests/test_qualification.py
index b46091c..2f79651 100644
--- a/tests/test_qualification.py
+++ b/tests/test_qualification.py
@@ -14,9 +14,9 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import mock
-import pytest
+from unittest import mock
 
+import pytest
 from django.test import override_settings
 
 from welco.forms import QualificationForm
diff --git a/tests/test_source_maarch.py b/tests/test_source_maarch.py
index c323122..c783fe8 100644
--- a/tests/test_source_maarch.py
+++ b/tests/test_source_maarch.py
@@ -17,14 +17,12 @@
 import json
 
 import pytest
-
 from django.contrib.auth.models import User
 from django.utils.encoding import force_text
-
-from httmock import urlmatch, HTTMock
+from httmock import HTTMock, urlmatch
 
 
-class BaseMock(object):
+class BaseMock:
     def __init__(self, netloc):
         self.netloc = netloc
         self.clear()
@@ -177,8 +175,10 @@ PDF_MOCK = b'%PDF-1.4 ...'
 
 def test_feed(settings, app, maarch, wcs, user):
     import base64
-    from django.core.management import call_command
+
     from django.contrib.contenttypes.models import ContentType
+    from django.core.management import call_command
+
     from welco.sources.mail.models import Mail
 
     app.set_user(user.username)
diff --git a/tests/test_source_phone.py b/tests/test_source_phone.py
index 4f9415d..6cae2c6 100644
--- a/tests/test_source_phone.py
+++ b/tests/test_source_phone.py
@@ -18,9 +18,8 @@ import json
 import re
 
 import pytest
-
-from django.urls import reverse
 from django.test import override_settings
+from django.urls import reverse
 from django.utils import six
 from django.utils.encoding import force_text
 from django.utils.timezone import now, timedelta
@@ -166,10 +165,10 @@ def test_current_calls(user, client):
     assert response['content-type'] == 'application/json'
     payload = response.json()
     assert isinstance(payload, dict)
-    assert set(payload.keys()) == set(['err', 'data'])
+    assert set(payload.keys()) == {'err', 'data'}
     assert payload['err'] == 0
     data = payload['data']
-    assert set(data.keys()) == set(['calls', 'lines', 'all-lines'])
+    assert set(data.keys()) == {'calls', 'lines', 'all-lines'}
     assert isinstance(data['calls'], list)
     assert isinstance(data['lines'], list)
     assert isinstance(data['all-lines'], list)
@@ -177,14 +176,14 @@ def test_current_calls(user, client):
     assert len(data['lines']) == 5
     assert len(data['all-lines']) == 10
     for call in data['calls']:
-        assert set(call.keys()) <= set(['caller', 'callee', 'start', 'data'])
-        assert isinstance(call['caller'], six.string_types)
-        assert isinstance(call['callee'], six.string_types)
-        assert isinstance(call['start'], six.string_types)
+        assert set(call.keys()) <= {'caller', 'callee', 'start', 'data'}
+        assert isinstance(call['caller'], str)
+        assert isinstance(call['callee'], str)
+        assert isinstance(call['start'], str)
         if 'data' in call:
             assert isinstance(call['data'], dict)
-    assert len([call for call in data['lines'] if isinstance(call, six.string_types)]) == 5
-    assert len([call for call in data['all-lines'] if isinstance(call, six.string_types)]) == 10
+    assert len([call for call in data['lines'] if isinstance(call, str)]) == 5
+    assert len([call for call in data['all-lines'] if isinstance(call, str)]) == 10
 
     # unregister user to all remaining lines
     for number in range(0, 5):
@@ -194,9 +193,9 @@ def test_current_calls(user, client):
     assert response['content-type'] == 'application/json'
     payload = response.json()
     assert isinstance(payload, dict)
-    assert set(payload.keys()) == set(['err', 'data'])
+    assert set(payload.keys()) == {'err', 'data'}
     assert payload['err'] == 0
-    assert set(payload['data'].keys()) == set(['calls', 'lines', 'all-lines'])
+    assert set(payload['data'].keys()) == {'calls', 'lines', 'all-lines'}
     assert len(payload['data']['calls']) == 0
     assert len(payload['data']['lines']) == 0
     assert len(payload['data']['all-lines']) == 10
diff --git a/welco/contacts/forms.py b/welco/contacts/forms.py
index e9d890a..2aa1976 100644
--- a/welco/contacts/forms.py
+++ b/welco/contacts/forms.py
@@ -15,8 +15,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from django import forms
-from django.utils.translation import ugettext_lazy as _, pgettext_lazy
-
+from django.utils.translation import pgettext_lazy
+from django.utils.translation import ugettext_lazy as _
 
 DEFAULT_TITLE_CHOICES = (
     ('', ''),
diff --git a/welco/contacts/views.py b/welco/contacts/views.py
index 331195b..43c2dcd 100644
--- a/welco/contacts/views.py
+++ b/welco/contacts/views.py
@@ -17,9 +17,9 @@
 import json
 import logging
 import random
-import requests
 import time
 
+import requests
 from django import template
 from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
@@ -27,14 +27,14 @@ from django.core.exceptions import PermissionDenied
 from django.http import HttpResponse
 from django.template import RequestContext
 from django.views.decorators.csrf import csrf_exempt
-from django.views.generic import TemplateView, FormView
+from django.views.generic import FormView, TemplateView
 
 from welco.utils import get_wcs_data, sign_url
 
 from .forms import ContactAddForm
 
 
-class HomeZone(object):
+class HomeZone:
     def __init__(self, request):
         self.request = request
 
@@ -47,7 +47,7 @@ class ContactsZone(TemplateView):
     template_name = 'contacts/zone.html'
 
     def get_context_data(self, **kwargs):
-        context = super(ContactsZone, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['source_pk'] = self.request.GET.get('source_pk')
         if 'source_pk' in self.request.GET:
             source_class = ContentType.objects.get(id=self.request.GET['source_type']).model_class()
@@ -68,7 +68,7 @@ zone = csrf_exempt(ContactsZone.as_view())
 
 
 def search_json(request):
-    user_groups = set([x.name for x in request.user.groups.all()])
+    user_groups = {x.name for x in request.user.groups.all()}
     for channel in settings.CHANNEL_ROLES:
         channel_groups = set(settings.CHANNEL_ROLES[channel])
         if user_groups.intersection(channel_groups):
@@ -104,7 +104,7 @@ class ContactDetailFragmentView(TemplateView):
     template_name = 'contacts/contact_detail_fragment.html'
 
     def get_context_data(self, **kwargs):
-        context = super(ContactDetailFragmentView, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
 
         user_id = self.kwargs.get('slug').split('-')[-1]
         user_details = get_wcs_data('api/users/%s/' % user_id)
diff --git a/welco/forms.py b/welco/forms.py
index 0c94561..b0cac84 100644
--- a/welco/forms.py
+++ b/welco/forms.py
@@ -24,7 +24,7 @@ class QualificationForm(forms.Form):
     formdef_reference = forms.CharField(label=_('Associated Form'))
 
     def __init__(self, user, *args, **kwargs):
-        super(QualificationForm, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         params = {'backoffice-submission': 'on'}
         if hasattr(user, 'saml_identifiers') and user.saml_identifiers.exists():
             params['NameID'] = user.saml_identifiers.first().name_id
diff --git a/welco/kb/forms.py b/welco/kb/forms.py
index 9e0feef..b84d2fa 100644
--- a/welco/kb/forms.py
+++ b/welco/kb/forms.py
@@ -38,4 +38,4 @@ class PageForm(forms.ModelForm):
                 i += 1
                 slug = '%s-%s' % (base_slug, i)
             self.instance.slug = slug
-        return super(PageForm, self).save(commit=commit)
+        return super().save(commit=commit)
diff --git a/welco/kb/migrations/0001_initial.py b/welco/kb/migrations/0001_initial.py
index 10fdb7b..40cf809 100644
--- a/welco/kb/migrations/0001_initial.py
+++ b/welco/kb/migrations/0001_initial.py
@@ -1,8 +1,5 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
 import ckeditor.fields
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/kb/migrations/0002_page_keywords.py b/welco/kb/migrations/0002_page_keywords.py
index b1980a6..0d5e3a7 100644
--- a/welco/kb/migrations/0002_page_keywords.py
+++ b/welco/kb/migrations/0002_page_keywords.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/kb/migrations/0003_page_tags.py b/welco/kb/migrations/0003_page_tags.py
index 0f76b13..80a9677 100644
--- a/welco/kb/migrations/0003_page_tags.py
+++ b/welco/kb/migrations/0003_page_tags.py
@@ -1,8 +1,5 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
 import taggit.managers
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/kb/migrations/0004_remove_page_keywords.py b/welco/kb/migrations/0004_remove_page_keywords.py
index 099b634..c4826f2 100644
--- a/welco/kb/migrations/0004_remove_page_keywords.py
+++ b/welco/kb/migrations/0004_remove_page_keywords.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/kb/models.py b/welco/kb/models.py
index 7c40dfa..bd6370f 100644
--- a/welco/kb/models.py
+++ b/welco/kb/models.py
@@ -14,11 +14,10 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from django.urls import reverse
-from django.db import models
-from django.utils.translation import ugettext_lazy as _
-
 from ckeditor.fields import RichTextField
+from django.db import models
+from django.urls import reverse
+from django.utils.translation import ugettext_lazy as _
 from taggit.managers import TaggableManager
 
 
diff --git a/welco/kb/search_indexes.py b/welco/kb/search_indexes.py
index 5cbafed..3f723e6 100644
--- a/welco/kb/search_indexes.py
+++ b/welco/kb/search_indexes.py
@@ -17,7 +17,6 @@
 import html
 
 from django.utils.html import strip_tags
-
 from haystack import indexes
 
 from .models import Page
diff --git a/welco/kb/views.py b/welco/kb/views.py
index 64366c4..3cf2e5d 100644
--- a/welco/kb/views.py
+++ b/welco/kb/views.py
@@ -20,20 +20,19 @@ from django import template
 from django.conf import settings
 from django.contrib.auth.decorators import login_required, user_passes_test
 from django.core.exceptions import PermissionDenied
-from django.urls import reverse_lazy
 from django.db.models import Count
 from django.http import HttpResponse, HttpResponseRedirect
 from django.template import RequestContext
+from django.urls import reverse_lazy
 from django.views.decorators.csrf import csrf_exempt
-from django.views.generic import DetailView, CreateView, UpdateView, ListView, DeleteView, TemplateView
-
+from django.views.generic import CreateView, DeleteView, DetailView, ListView, TemplateView, UpdateView
 from haystack.forms import SearchForm
 from haystack.generic_views import SearchView
 from haystack.query import SearchQuerySet
 from taggit.models import Tag
 
-from .models import Page
 from .forms import PageForm
+from .models import Page
 
 
 def check_user_perms(user, access=False):
@@ -42,7 +41,7 @@ def check_user_perms(user, access=False):
         allowed_roles.extend(settings.KB_ACCESS_ROLES)
     if settings.KB_ROLE:
         allowed_roles.append(settings.KB_ROLE)  # legacy
-    user_groups = set([x.name for x in user.groups.all()])
+    user_groups = {x.name for x in user.groups.all()}
     return user_groups.intersection(allowed_roles)
 
 
@@ -56,10 +55,10 @@ class PageListView(ListView):
 
     def dispatch(self, request, *args, **kwargs):
         check_request_perms(request, access=True)
-        return super(PageListView, self).dispatch(request, *args, **kwargs)
+        return super().dispatch(request, *args, **kwargs)
 
     def get_context_data(self, **kwargs):
-        context = super(PageListView, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['form'] = SearchForm()
         context['can_manage'] = check_user_perms(self.request.user)
         return context
@@ -74,7 +73,7 @@ class PageAddView(CreateView):
 
     def dispatch(self, request, *args, **kwargs):
         check_request_perms(request)
-        return super(PageAddView, self).dispatch(request, *args, **kwargs)
+        return super().dispatch(request, *args, **kwargs)
 
 
 page_add = login_required(PageAddView.as_view())
@@ -86,7 +85,7 @@ class PageEditView(UpdateView):
 
     def dispatch(self, request, *args, **kwargs):
         check_request_perms(request)
-        return super(PageEditView, self).dispatch(request, *args, **kwargs)
+        return super().dispatch(request, *args, **kwargs)
 
 
 page_edit = login_required(PageEditView.as_view())
@@ -97,10 +96,10 @@ class PageDetailView(DetailView):
 
     def dispatch(self, request, *args, **kwargs):
         check_request_perms(request, access=True)
-        return super(PageDetailView, self).dispatch(request, *args, **kwargs)
+        return super().dispatch(request, *args, **kwargs)
 
     def get_context_data(self, **kwargs):
-        context = super(PageDetailView, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['can_manage'] = check_user_perms(self.request.user)
         return context
 
@@ -122,7 +121,7 @@ class PageDeleteView(DeleteView):
 
     def dispatch(self, request, *args, **kwargs):
         check_request_perms(request)
-        return super(PageDeleteView, self).dispatch(request, *args, **kwargs)
+        return super().dispatch(request, *args, **kwargs)
 
 
 page_delete = login_required(PageDeleteView.as_view())
@@ -134,7 +133,7 @@ class PageSearchView(SearchView):
 
     def dispatch(self, request, *args, **kwargs):
         check_request_perms(request, access=True)
-        return super(PageSearchView, self).dispatch(request, *args, **kwargs)
+        return super().dispatch(request, *args, **kwargs)
 
 
 page_search = login_required(PageSearchView.as_view())
@@ -144,7 +143,7 @@ class KbZone(TemplateView):
     template_name = 'kb/zone.html'
 
     def get_context_data(self, **kwargs):
-        context = super(KbZone, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['source_pk'] = self.request.GET.get('source_pk')
         context['form'] = SearchForm()
         context['tags'] = (
@@ -190,7 +189,7 @@ def page_search_json(request):
     return response
 
 
-class HomeZone(object):
+class HomeZone:
     def __init__(self, request):
         self.request = request
 
diff --git a/welco/monkeypatch.py b/welco/monkeypatch.py
index d31465c..c70bfbb 100644
--- a/welco/monkeypatch.py
+++ b/welco/monkeypatch.py
@@ -14,16 +14,15 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from django.urls import reverse
+import ckeditor.widgets
 from django.forms.utils import flatatt
 from django.template.loader import render_to_string
+from django.urls import reverse
 from django.utils.encoding import force_text
 from django.utils.html import conditional_escape
 from django.utils.safestring import mark_safe
 from django.utils.translation import get_language
 
-import ckeditor.widgets
-
 
 def ckeditor_render(self, name, value, attrs=None, renderer=None):
     if value is None:
diff --git a/welco/qualif/migrations/0001_initial.py b/welco/qualif/migrations/0001_initial.py
index 61c9943..e4de212 100644
--- a/welco/qualif/migrations/0001_initial.py
+++ b/welco/qualif/migrations/0001_initial.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/qualif/migrations/0002_association_triaged.py b/welco/qualif/migrations/0002_association_triaged.py
index b1b0a47..faf44c5 100644
--- a/welco/qualif/migrations/0002_association_triaged.py
+++ b/welco/qualif/migrations/0002_association_triaged.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/qualif/migrations/0003_association_comments.py b/welco/qualif/migrations/0003_association_comments.py
index 7accd18..a3e82cd 100644
--- a/welco/qualif/migrations/0003_association_comments.py
+++ b/welco/qualif/migrations/0003_association_comments.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/qualif/migrations/0004_association_user_id.py b/welco/qualif/migrations/0004_association_user_id.py
index 476ba2d..fc1454c 100644
--- a/welco/qualif/migrations/0004_association_user_id.py
+++ b/welco/qualif/migrations/0004_association_user_id.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/qualif/migrations/0005_auto_20151009_1110.py b/welco/qualif/migrations/0005_auto_20151009_1110.py
index 8c83224..2df6dcf 100644
--- a/welco/qualif/migrations/0005_auto_20151009_1110.py
+++ b/welco/qualif/migrations/0005_auto_20151009_1110.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/qualif/migrations/0006_remove_association_user_id.py b/welco/qualif/migrations/0006_remove_association_user_id.py
index 49a22bb..94240c4 100644
--- a/welco/qualif/migrations/0006_remove_association_user_id.py
+++ b/welco/qualif/migrations/0006_remove_association_user_id.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/qualif/migrations/0007_remove_association_triaged.py b/welco/qualif/migrations/0007_remove_association_triaged.py
index 5d79a2a..680baba 100644
--- a/welco/qualif/migrations/0007_remove_association_triaged.py
+++ b/welco/qualif/migrations/0007_remove_association_triaged.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/qualif/migrations/0008_association_formdata_url_backoffice.py b/welco/qualif/migrations/0008_association_formdata_url_backoffice.py
index 91ddc18..03c8900 100644
--- a/welco/qualif/migrations/0008_association_formdata_url_backoffice.py
+++ b/welco/qualif/migrations/0008_association_formdata_url_backoffice.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 
 
diff --git a/welco/qualif/models.py b/welco/qualif/models.py
index 6eaa6b5..0da32c4 100644
--- a/welco/qualif/models.py
+++ b/welco/qualif/models.py
@@ -14,13 +14,13 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes.fields import GenericForeignKey
-from django.urls import reverse
+from django.contrib.contenttypes.models import ContentType
 from django.db import models
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
-from welco.utils import get_wcs_formdef_details, push_wcs_formdata, get_wcs_services
+from welco.utils import get_wcs_formdef_details, get_wcs_services, push_wcs_formdata
 
 
 class Association(models.Model):
diff --git a/welco/settings.py b/welco/settings.py
index 9bc97ff..cfe3dc0 100644
--- a/welco/settings.py
+++ b/welco/settings.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 """
 Django settings for welco project.
 
@@ -11,6 +9,7 @@ https://docs.djangoproject.com/en/1.7/ref/settings/
 """
 
 import os
+
 from django.conf import global_settings
 from django.utils.translation import ugettext_lazy as _
 
diff --git a/welco/sources/counter/migrations/0001_initial.py b/welco/sources/counter/migrations/0001_initial.py
index d154133..2962d06 100644
--- a/welco/sources/counter/migrations/0001_initial.py
+++ b/welco/sources/counter/migrations/0001_initial.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/counter/views.py b/welco/sources/counter/views.py
index 6138f90..e45e9c9 100644
--- a/welco/sources/counter/views.py
+++ b/welco/sources/counter/views.py
@@ -18,17 +18,17 @@ import json
 
 from django import template
 from django.conf import settings
+from django.contrib.auth.decorators import login_required
 from django.contrib.contenttypes.models import ContentType
+from django.http import HttpResponse
 from django.template import RequestContext
 from django.views.decorators.csrf import csrf_exempt
-from django.contrib.auth.decorators import login_required
-from django.http import HttpResponse
 from django.views.generic import TemplateView
 
 from .models import CounterPresence
 
 
-class Home(object):
+class Home:
     source_key = 'counter'
 
     def __init__(self, request, **kwargs):
@@ -46,7 +46,7 @@ class CounterZone(TemplateView):
     template_name = 'welco/counter_home.html'
 
     def get_context_data(self, **kwargs):
-        context = super(CounterZone, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['source_type'] = ContentType.objects.get_for_model(CounterPresence)
         new_source = CounterPresence()
         new_source.save()
diff --git a/welco/sources/mail/__init__.py b/welco/sources/mail/__init__.py
index 5a86f3f..94c300e 100644
--- a/welco/sources/mail/__init__.py
+++ b/welco/sources/mail/__init__.py
@@ -26,9 +26,10 @@ class AppConfig(django.apps.AppConfig):
         return urls.urlpatterns
 
     def ready(self):
-        from welco.qualif.models import Association
         from django.db.models import signals
 
+        from welco.qualif.models import Association
+
         signals.post_save.connect(self.association_post_save, sender=Association)
 
     def association_post_save(self, sender, instance, **kwargs):
diff --git a/welco/sources/mail/forms.py b/welco/sources/mail/forms.py
index fd4136a..351496a 100644
--- a/welco/sources/mail/forms.py
+++ b/welco/sources/mail/forms.py
@@ -15,8 +15,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from django import forms
-from django.utils.translation import ugettext_lazy as _
 from django.conf import settings
+from django.utils.translation import ugettext_lazy as _
 
 
 class MailQualificationForm(forms.Form):
diff --git a/welco/sources/mail/maarch.py b/welco/sources/mail/maarch.py
index f84f46a..16d75b2 100644
--- a/welco/sources/mail/maarch.py
+++ b/welco/sources/mail/maarch.py
@@ -16,11 +16,10 @@
 
 import base64
 
+import requests
 from dateutil.parser import parse as parse_datetime
 from django.utils import six
 from django.utils.six.moves.urllib import parse as urlparse
-
-import requests
 from requests.adapters import HTTPAdapter
 from requests.packages.urllib3.util.retry import Retry
 
@@ -29,7 +28,7 @@ class MaarchError(Exception):
     pass
 
 
-class MaarchCourrier(object):
+class MaarchCourrier:
     url = None
     username = None
     password = None
@@ -44,7 +43,7 @@ class MaarchCourrier(object):
     def __repr__(self):
         return '<MaarchCourrier url:%s>' % self.url
 
-    class Courrier(object):
+    class Courrier:
         content = None
         format = None
         status = None
@@ -89,7 +88,7 @@ class MaarchCourrier(object):
             data = {key: self.__dict__[key] for key in self.__dict__ if key not in excluded_keys}
             if data:
                 for key, value in data.items():
-                    if isinstance(value, six.string_types):
+                    if isinstance(value, str):
                         d.append({'column': key, 'value': value, 'type': 'string'})
                     elif isinstance(value, int):
                         d.append({'column': key, 'value': str(value), 'type': 'int'})
diff --git a/welco/sources/mail/management/commands/feed_mail.py b/welco/sources/mail/management/commands/feed_mail.py
index baef5ea..45dc0d0 100644
--- a/welco/sources/mail/management/commands/feed_mail.py
+++ b/welco/sources/mail/management/commands/feed_mail.py
@@ -14,8 +14,8 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from optparse import make_option
 import os
+from optparse import make_option
 
 from django.core.files import File
 from django.core.management.base import BaseCommand, CommandError
diff --git a/welco/sources/mail/management/commands/feed_mail_maarch.py b/welco/sources/mail/management/commands/feed_mail_maarch.py
index 88631c3..9856fc3 100644
--- a/welco/sources/mail/management/commands/feed_mail_maarch.py
+++ b/welco/sources/mail/management/commands/feed_mail_maarch.py
@@ -14,12 +14,12 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from optparse import make_option
 import os
+from optparse import make_option
 
+from django.conf import settings
 from django.core.files.base import ContentFile
 from django.core.management.base import BaseCommand, CommandError
-from django.conf import settings
 from django.db import transaction
 
 from ...models import Mail
diff --git a/welco/sources/mail/migrations/0001_initial.py b/welco/sources/mail/migrations/0001_initial.py
index b6ef78c..a243fc5 100644
--- a/welco/sources/mail/migrations/0001_initial.py
+++ b/welco/sources/mail/migrations/0001_initial.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0002_auto_20150831_1538.py b/welco/sources/mail/migrations/0002_auto_20150831_1538.py
index 77dd556..876776c 100644
--- a/welco/sources/mail/migrations/0002_auto_20150831_1538.py
+++ b/welco/sources/mail/migrations/0002_auto_20150831_1538.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0003_auto_20151009_1144.py b/welco/sources/mail/migrations/0003_auto_20151009_1144.py
index 01d43a9..4d847e3 100644
--- a/welco/sources/mail/migrations/0003_auto_20151009_1144.py
+++ b/welco/sources/mail/migrations/0003_auto_20151009_1144.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0004_mail_contact_id.py b/welco/sources/mail/migrations/0004_mail_contact_id.py
index adc0926..eae68ac 100644
--- a/welco/sources/mail/migrations/0004_mail_contact_id.py
+++ b/welco/sources/mail/migrations/0004_mail_contact_id.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0005_auto_20151010_1819.py b/welco/sources/mail/migrations/0005_auto_20151010_1819.py
index 0967013..781f2d6 100644
--- a/welco/sources/mail/migrations/0005_auto_20151010_1819.py
+++ b/welco/sources/mail/migrations/0005_auto_20151010_1819.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0006_mail_note.py b/welco/sources/mail/migrations/0006_mail_note.py
index 6fda77a..988df12 100644
--- a/welco/sources/mail/migrations/0006_mail_note.py
+++ b/welco/sources/mail/migrations/0006_mail_note.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0007_mail_mail_number.py b/welco/sources/mail/migrations/0007_mail_mail_number.py
index 6aa7b9c..6be26ed 100644
--- a/welco/sources/mail/migrations/0007_mail_mail_number.py
+++ b/welco/sources/mail/migrations/0007_mail_mail_number.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0008_remove_mail_mail_number.py b/welco/sources/mail/migrations/0008_remove_mail_mail_number.py
index 3f5187d..6a0cc40 100644
--- a/welco/sources/mail/migrations/0008_remove_mail_mail_number.py
+++ b/welco/sources/mail/migrations/0008_remove_mail_mail_number.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/mail/migrations/0009_mail_scanner_category.py b/welco/sources/mail/migrations/0009_mail_scanner_category.py
index e41d8e3..9c0222a 100644
--- a/welco/sources/mail/migrations/0009_mail_scanner_category.py
+++ b/welco/sources/mail/migrations/0009_mail_scanner_category.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 
 
diff --git a/welco/sources/mail/migrations/0010_mail_subject.py b/welco/sources/mail/migrations/0010_mail_subject.py
index e7642f2..e2f8743 100644
--- a/welco/sources/mail/migrations/0010_mail_subject.py
+++ b/welco/sources/mail/migrations/0010_mail_subject.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 
 
diff --git a/welco/sources/mail/migrations/0011_mail_reference.py b/welco/sources/mail/migrations/0011_mail_reference.py
index a1af01e..e63fe43 100644
--- a/welco/sources/mail/migrations/0011_mail_reference.py
+++ b/welco/sources/mail/migrations/0011_mail_reference.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 
 
diff --git a/welco/sources/mail/migrations/0012_mail_external_id.py b/welco/sources/mail/migrations/0012_mail_external_id.py
index 430f910..d1ae7c3 100644
--- a/welco/sources/mail/migrations/0012_mail_external_id.py
+++ b/welco/sources/mail/migrations/0012_mail_external_id.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 
 
diff --git a/welco/sources/mail/models.py b/welco/sources/mail/models.py
index 365847e..ea185e0 100644
--- a/welco/sources/mail/models.py
+++ b/welco/sources/mail/models.py
@@ -15,16 +15,16 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import re
-import requests
 import subprocess
 
+import requests
 from django.conf import settings
 from django.contrib.contenttypes.fields import GenericRelation
 from django.contrib.contenttypes.models import ContentType
-from django.urls import reverse
 from django.db import models
 from django.db.models.signals import post_save
 from django.dispatch import receiver
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from welco.qualif.models import Association
diff --git a/welco/sources/mail/urls.py b/welco/sources/mail/urls.py
index 5df4848..359ede8 100644
--- a/welco/sources/mail/urls.py
+++ b/welco/sources/mail/urls.py
@@ -16,7 +16,7 @@
 
 from django.conf.urls import url
 
-from .views import viewer, feeder, qualification_save, edit_note, note, reject, mail_count, mail_response
+from .views import edit_note, feeder, mail_count, mail_response, note, qualification_save, reject, viewer
 
 urlpatterns = [
     url('viewer/$', viewer, name='mail-viewer'),
diff --git a/welco/sources/mail/utils.py b/welco/sources/mail/utils.py
index 2d9b1a0..ee4b97d 100644
--- a/welco/sources/mail/utils.py
+++ b/welco/sources/mail/utils.py
@@ -32,7 +32,7 @@ class WelcoMaarchCourrier(MaarchCourrier):
         grc_response_status,
         batch_size=10,
     ):
-        super(WelcoMaarchCourrier, self).__init__(url, username, password)
+        super().__init__(url, username, password)
         self.grc_status = grc_status
         self.grc_received_status = grc_received_status
         self.grc_send_status = grc_send_status
diff --git a/welco/sources/mail/views.py b/welco/sources/mail/views.py
index 64979a3..bccd171 100644
--- a/welco/sources/mail/views.py
+++ b/welco/sources/mail/views.py
@@ -18,27 +18,25 @@ import json
 import logging
 
 from django import template
+from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.contrib.contenttypes.models import ContentType
-from django.contrib import messages
-from django.urls import reverse
-from django.template import RequestContext
+from django.db.transaction import atomic
 from django.http import HttpResponse, HttpResponseRedirect
+from django.template import RequestContext
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 from django.views.decorators.csrf import csrf_exempt
 from django.views.generic import TemplateView
-from django.db.transaction import atomic
-
-from rest_framework import authentication, serializers, permissions, status
+from rest_framework import authentication, permissions, serializers, status
 from rest_framework.generics import GenericAPIView
 from rest_framework.response import Response
 
 from welco.utils import response_for_json
 
-from .models import Mail
 from .forms import MailQualificationForm
-from .utils import get_maarch, MaarchError
-
+from .models import Mail
+from .utils import MaarchError, get_maarch
 
 logger = logging.getLogger(__name__)
 
@@ -64,7 +62,7 @@ class Feeder(TemplateView):
 feeder = login_required(csrf_exempt(Feeder.as_view()))
 
 
-class Home(object):
+class Home:
     source_key = 'mail'
     display_filter = True
     allow_reject = True
@@ -112,7 +110,7 @@ class EditNote(TemplateView):
     template_name = 'welco/mail_edit_note.html'
 
     def get_context_data(self, **kwargs):
-        context = super(EditNote, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['mail'] = Mail.objects.get(id=self.request.GET['mail'])
         return context
 
diff --git a/welco/sources/phone/migrations/0001_initial.py b/welco/sources/phone/migrations/0001_initial.py
index 6072cd7..3074b62 100644
--- a/welco/sources/phone/migrations/0001_initial.py
+++ b/welco/sources/phone/migrations/0001_initial.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 
 
diff --git a/welco/sources/phone/migrations/0002_auto_20151028_1635.py b/welco/sources/phone/migrations/0002_auto_20151028_1635.py
index 4c1dd3d..8154322 100644
--- a/welco/sources/phone/migrations/0002_auto_20151028_1635.py
+++ b/welco/sources/phone/migrations/0002_auto_20151028_1635.py
@@ -1,11 +1,8 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import migrations, models
-from django.utils.timezone import utc
-from django.utils.timezone import now
 import datetime
+
 from django.conf import settings
+from django.db import migrations, models
+from django.utils.timezone import now, utc
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/phone/migrations/0003_auto_20151103_1202.py b/welco/sources/phone/migrations/0003_auto_20151103_1202.py
index ea90523..4348653 100644
--- a/welco/sources/phone/migrations/0003_auto_20151103_1202.py
+++ b/welco/sources/phone/migrations/0003_auto_20151103_1202.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/phone/migrations/0004_auto_20160204_0252.py b/welco/sources/phone/migrations/0004_auto_20160204_0252.py
index 10efdac..12e2eee 100644
--- a/welco/sources/phone/migrations/0004_auto_20160204_0252.py
+++ b/welco/sources/phone/migrations/0004_auto_20160204_0252.py
@@ -1,7 +1,4 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
diff --git a/welco/sources/phone/models.py b/welco/sources/phone/models.py
index 7d152cd..c3f0c67 100644
--- a/welco/sources/phone/models.py
+++ b/welco/sources/phone/models.py
@@ -18,10 +18,10 @@ import logging
 
 from django.conf import settings
 from django.contrib.contenttypes.fields import GenericRelation
-from django.urls import reverse
 from django.db import models
-from django.utils.translation import ugettext_lazy as _
+from django.urls import reverse
 from django.utils.timezone import now, timedelta
+from django.utils.translation import ugettext_lazy as _
 
 from welco.qualif.models import Association
 
diff --git a/welco/sources/phone/views.py b/welco/sources/phone/views.py
index dc50404..f3143f3 100644
--- a/welco/sources/phone/views.py
+++ b/welco/sources/phone/views.py
@@ -19,20 +19,20 @@ import logging
 
 from django import template
 from django.conf import settings
-from django.contrib.contenttypes.models import ContentType
-from django.template import RequestContext
-from django.views.decorators.csrf import csrf_exempt
 from django.contrib.auth.decorators import login_required
-from django.http import HttpResponseBadRequest, HttpResponse
+from django.contrib.contenttypes.models import ContentType
+from django.http import HttpResponse, HttpResponseBadRequest
+from django.template import RequestContext
 from django.utils import six
 from django.utils.encoding import force_text
 from django.utils.timezone import now
+from django.views.decorators.csrf import csrf_exempt
 from django.views.generic import TemplateView
 
 from .models import PhoneCall, PhoneLine
 
 
-class Home(object):
+class Home:
     source_key = 'phone'
 
     def __init__(self, request, **kwargs):
@@ -60,7 +60,7 @@ class PhoneZone(TemplateView):
                 username = username[0].split('@', 1)[0][:80]  # remove realm
                 if username:
                     PhoneLine.take(callee=username, user=self.request.user)
-        context = super(PhoneZone, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['source_type'] = ContentType.objects.get_for_model(PhoneCall)
         context['phonelines'] = PhoneLine.objects.filter(users__id=self.request.user.id)
         context['phonecalls'] = PhoneCall.get_current_calls(self.request.user)
@@ -87,15 +87,18 @@ def call_event(request):
     try:
         payload = json.loads(force_text(request.body))
         assert isinstance(payload, dict), 'payload is not a JSON object'
-        assert set(payload.keys()) <= set(
-            ['event', 'caller', 'callee', 'data']
-        ), 'payload keys must be "event", "caller", "callee" and optionnaly "data"'
-        assert set(['event', 'caller', 'callee']) <= set(
+        assert set(payload.keys()) <= {
+            'event',
+            'caller',
+            'callee',
+            'data',
+        }, 'payload keys must be "event", "caller", "callee" and optionnaly "data"'
+        assert {'event', 'caller', 'callee'} <= set(
             payload.keys()
         ), 'payload keys must be "event", "caller", "callee" and optionnaly "data"'
         assert payload['event'] in ('start', 'stop'), 'event must be "start" or "stop"'
-        assert isinstance(payload['caller'], six.string_types), 'caller must be a string'
-        assert isinstance(payload['callee'], six.string_types), 'callee must be a string'
+        assert isinstance(payload['caller'], str), 'caller must be a string'
+        assert isinstance(payload['callee'], str), 'callee must be a string'
         if 'data' in payload:
             assert isinstance(payload['data'], dict), 'data must be a JSON object'
     except (TypeError, ValueError, AssertionError) as e:
@@ -208,7 +211,7 @@ def take_line(request):
             json.dumps({'err': 1, 'msg': force_text(e)}), content_type='application/json'
         )
     PhoneLine.take(payload['callee'], request.user)
-    logger.info(u'user %s took line %s', request.user, payload['callee'])
+    logger.info('user %s took line %s', request.user, payload['callee'])
     return HttpResponse(json.dumps({'err': 0}), content_type='application/json')
 
 
@@ -229,5 +232,5 @@ def release_line(request):
             json.dumps({'err': 1, 'msg': force_text(e)}), content_type='application/json'
         )
     PhoneLine.release(payload['callee'], request.user)
-    logger.info(u'user %s released line %s', request.user, payload['callee'])
+    logger.info('user %s released line %s', request.user, payload['callee'])
     return HttpResponse(json.dumps({'err': 0}), content_type='application/json')
diff --git a/welco/urls.py b/welco/urls.py
index fc9fc5b..db0400e 100644
--- a/welco/urls.py
+++ b/welco/urls.py
@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+from ckeditor import views as ckeditor_views
 from django.conf import settings
 from django.conf.urls import include, url
 from django.conf.urls.static import static
@@ -21,16 +22,13 @@ from django.contrib import admin
 from django.contrib.staticfiles.urls import staticfiles_urlpatterns
 from django.views.decorators.cache import never_cache
 
-from ckeditor import views as ckeditor_views
+import welco.contacts.views
+import welco.kb.views
+import welco.views
 
 from . import apps
 from .kb.views import kb_manager_required
 
-import welco.views
-import welco.contacts.views
-import welco.kb.views
-
-
 urlpatterns = [
     url(r'^$', welco.views.home, name='home'),
     url(r'^mail/$', welco.views.home_mail, name='home-mail'),
diff --git a/welco/utils.py b/welco/utils.py
index b179003..3a68648 100644
--- a/welco/utils.py
+++ b/welco/utils.py
@@ -16,18 +16,18 @@
 
 import base64
 import datetime
-import hmac
 import hashlib
+import hmac
 import json
 import random
 import re
-import requests
 
+import requests
 from django.conf import settings
 from django.core.cache import cache
 from django.http import HttpResponse, HttpResponseBadRequest
 from django.utils.encoding import smart_bytes
-from django.utils.http import urlencode, quote
+from django.utils.http import quote, urlencode
 from django.utils.six.moves.urllib import parse as urlparse
 
 
diff --git a/welco/views.py b/welco/views.py
index 0e69fa8..860a549 100644
--- a/welco/views.py
+++ b/welco/views.py
@@ -16,17 +16,17 @@
 
 import json
 
+from django import template
 from django.conf import settings
 from django.contrib.auth import logout as auth_logout
 from django.contrib.auth import views as auth_views
 from django.contrib.auth.decorators import login_required
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import PermissionDenied
-from django.urls import reverse
 from django.http import HttpResponse, HttpResponseRedirect
 from django.shortcuts import resolve_url
-from django import template
 from django.template import RequestContext
+from django.urls import reverse
 from django.utils.encoding import force_text
 from django.utils.http import quote
 from django.utils.translation import ugettext_lazy as _
@@ -38,13 +38,14 @@ if 'mellon' in settings.INSTALLED_APPS:
 else:
     get_idps = lambda: []
 
-from .sources.mail.views import Home as MailHome
-from .sources.phone.views import Home as PhoneHome
-from .sources.counter.views import Home as CounterHome
-from .qualif.models import Association
-from .kb.views import HomeZone as KbHomeZone, check_user_perms as check_kb_user_perms
 from .contacts.views import HomeZone as ContactsHomeZone
 from .forms import QualificationForm
+from .kb.views import HomeZone as KbHomeZone
+from .kb.views import check_user_perms as check_kb_user_perms
+from .qualif.models import Association
+from .sources.counter.views import Home as CounterHome
+from .sources.mail.views import Home as MailHome
+from .sources.phone.views import Home as PhoneHome
 
 
 class LoginView(auth_views.LoginView):
@@ -59,7 +60,7 @@ class LoginView(auth_views.LoginView):
             except KeyError:
                 return HttpResponseBadRequest('invalid value for "next" parameter')
             return HttpResponseRedirect(resolve_url('mellon_login') + '?next=' + quoted_next_url)
-        return super(LoginView, self).dispatch(request, *args, **kwargs)
+        return super().dispatch(request, *args, **kwargs)
 
 
 login = LoginView.as_view()
@@ -80,7 +81,7 @@ class Qualification(TemplateView):
     template_name = 'welco/qualification_no_validation.html'
 
     def get_context_data(self, **kwargs):
-        context = super(Qualification, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['form'] = QualificationForm(self.request.user)
         context['source_type'] = self.request.GET['source_type']
         source_type = ContentType.objects.get(id=self.request.GET['source_type'])
@@ -112,21 +113,21 @@ class ChannelHome(TemplateView):
     source_klass = MailHome
 
     def check_user_ok(self):
-        user_groups = set([x.name for x in self.request.user.groups.all()])
+        user_groups = {x.name for x in self.request.user.groups.all()}
         channel_groups = set(settings.CHANNEL_ROLES[self.source_klass.source_key])
         return user_groups.intersection(channel_groups)
 
     def get_context_data(self, **kwargs):
         if not self.check_user_ok():
             raise PermissionDenied()
-        context = super(ChannelHome, self).get_context_data(**kwargs)
+        context = super().get_context_data(**kwargs)
         context['panels'] = [{'key': x, 'zone_url': x + '-zone'} for x in settings.SCREEN_PANELS]
         context['source'] = self.source_klass(self.request, **kwargs)
         context['kb'] = KbHomeZone(self.request)
         context['contacts'] = ContactsHomeZone(self.request)
         context['channels'] = []
 
-        user_groups = set([x.name for x in self.request.user.groups.all()])
+        user_groups = {x.name for x in self.request.user.groups.all()}
         for channel in settings.CHANNEL_ROLES:
             channel_groups = set(settings.CHANNEL_ROLES[channel])
             if user_groups.intersection(channel_groups):
@@ -136,7 +137,7 @@ class ChannelHome(TemplateView):
 
 @login_required
 def home(request):
-    user_groups = set([x.name for x in request.user.groups.all()])
+    user_groups = {x.name for x in request.user.groups.all()}
     for channel in settings.CHANNEL_ROLES:
         channel_groups = set(settings.CHANNEL_ROLES[channel])
         if user_groups.intersection(channel_groups):
@@ -209,7 +210,7 @@ def create_formdata(request, *args, **kwargs):
 @login_required
 def menu_json(request):
     response = HttpResponse(content_type='application/json')
-    user_groups = set([x.name for x in request.user.groups.all()])
+    user_groups = {x.name for x in request.user.groups.all()}
     menu = []
     labels = {
         'mail': _('Mails'),