diff --git a/mayan/apps/authentication/views.py b/mayan/apps/authentication/views.py
index 09d6db22d7..207aa05de3 100644
--- a/mayan/apps/authentication/views.py
+++ b/mayan/apps/authentication/views.py
@@ -7,9 +7,8 @@ from django.contrib.auth.views import (
     login, password_change, password_reset, password_reset_confirm,
     password_reset_complete, password_reset_done
 )
-from django.http import HttpResponse, HttpResponseRedirect
+from django.http import HttpResponseRedirect
 from django.shortcuts import redirect, resolve_url
-from django.template.loader import render_to_string
 from django.urls import reverse
 from django.utils.http import is_safe_url
 from django.utils.translation import ugettext_lazy as _
diff --git a/mayan/apps/checkouts/views.py b/mayan/apps/checkouts/views.py
index e5d7f6ef19..fcacd5a753 100644
--- a/mayan/apps/checkouts/views.py
+++ b/mayan/apps/checkouts/views.py
@@ -110,7 +110,7 @@ class CheckoutListView(DocumentListView):
                     'time.'
                 ),
                 'no_results_title': _('No documents have been checked out'),
-                'title': _('Documents checked out'),                
+                'title': _('Documents checked out'),
             }
         )
         return context
diff --git a/mayan/apps/common/exceptions.py b/mayan/apps/common/exceptions.py
index 8322d46e48..e74b95ecf5 100644
--- a/mayan/apps/common/exceptions.py
+++ b/mayan/apps/common/exceptions.py
@@ -15,6 +15,7 @@ class ActionError(BaseCommonException):
     it is used to announce that one item in the queryset failed to process.
     """
 
+
 class CompressionFileError(BaseCommonException):
     """
     Base exception for file decompression class
diff --git a/mayan/apps/common/templatetags/common_tags.py b/mayan/apps/common/templatetags/common_tags.py
index 7193c677ee..6b19585eb6 100644
--- a/mayan/apps/common/templatetags/common_tags.py
+++ b/mayan/apps/common/templatetags/common_tags.py
@@ -45,6 +45,7 @@ def check_sqlite():
 def get_collections():
     return Collection.get_all()
 
+
 @register.filter
 def get_encoded_parameter(item, parameters_dict):
     result = {}
diff --git a/mayan/apps/common/tests/test_compressed_files.py b/mayan/apps/common/tests/test_compressed_files.py
index 83f17fe3e0..5775fecd94 100644
--- a/mayan/apps/common/tests/test_compressed_files.py
+++ b/mayan/apps/common/tests/test_compressed_files.py
@@ -1,15 +1,13 @@
 from __future__ import unicode_literals
 
 from common.tests import BaseTestCase
-from django.test import override_settings
 
 from ..compressed_files import Archive, TarArchive, ZipArchive
 
 from .literals import (
-    TEST_COMPRESSED_FILE_CONTENTS, TEST_FILE_CONTENTS_1, TEST_FILE_CONTENTS_2,
-    TEST_FILE3_PATH, TEST_FILENAME1, TEST_FILENAME2, TEST_FILENAME3,
-    TEST_TAR_BZ2_FILE_PATH, TEST_TAR_FILE_PATH, TEST_TAR_GZ_FILE_PATH,
-    TEST_ZIP_FILE_PATH
+    TEST_COMPRESSED_FILE_CONTENTS, TEST_FILE_CONTENTS_1, TEST_FILE3_PATH,
+    TEST_FILENAME1, TEST_FILENAME3, TEST_TAR_BZ2_FILE_PATH,
+    TEST_TAR_FILE_PATH, TEST_TAR_GZ_FILE_PATH, TEST_ZIP_FILE_PATH
 )
 
 
@@ -43,7 +41,8 @@ class TarArchiveClassTestCase(BaseTestCase):
         with open(self.archive_path) as file_object:
             archive = Archive.open(file_object=file_object)
             self.assertEqual(
-                archive.member_contents(filename=self.member_name), self.member_contents
+                archive.member_contents(filename=self.member_name),
+                self.member_contents
             )
 
     def test_open_member(self):
diff --git a/mayan/apps/common/utils.py b/mayan/apps/common/utils.py
index e16ffda98d..8406efb1a1 100644
--- a/mayan/apps/common/utils.py
+++ b/mayan/apps/common/utils.py
@@ -10,7 +10,6 @@ from django.conf import settings
 from django.urls import resolve as django_resolve
 from django.urls.base import get_script_prefix
 from django.utils.datastructures import MultiValueDict
-from django.utils.encoding import force_text
 from django.utils.http import (
     urlencode as django_urlencode, urlquote as django_urlquote
 )
diff --git a/mayan/apps/converter/links.py b/mayan/apps/converter/links.py
index 09bb8ff301..f217428208 100644
--- a/mayan/apps/converter/links.py
+++ b/mayan/apps/converter/links.py
@@ -31,7 +31,7 @@ def get_kwargs_factory(variable_name):
 
 
 link_transformation_create = Link(
-    icon_class = icon_transformation_create,
+    icon_class=icon_transformation_create,
     kwargs=get_kwargs_factory('content_object'),
     permissions=(permission_transformation_create,),
     text=_('Create new transformation'), view='converter:transformation_create'
diff --git a/mayan/apps/converter/views.py b/mayan/apps/converter/views.py
index 63d4fbaa1d..ace519c2f7 100644
--- a/mayan/apps/converter/views.py
+++ b/mayan/apps/converter/views.py
@@ -216,7 +216,7 @@ class TransformationListView(SingleObjectListView):
             'no_results_icon': icon_transformation,
             'no_results_main_link': link_transformation_create.resolve(
                 context=RequestContext(
-                    self.request, {'content_object': self.content_object,}
+                    self.request, {'content_object': self.content_object}
                 )
             ),
             'no_results_text': _(
diff --git a/mayan/apps/document_indexing/links.py b/mayan/apps/document_indexing/links.py
index 8e2e3e4430..42e3b94d6d 100644
--- a/mayan/apps/document_indexing/links.py
+++ b/mayan/apps/document_indexing/links.py
@@ -12,7 +12,7 @@ from .permissions import (
     permission_document_indexing_create, permission_document_indexing_edit,
     permission_document_indexing_delete,
     permission_document_indexing_instance_view,
-    permission_document_indexing_rebuild,permission_document_indexing_view
+    permission_document_indexing_rebuild, permission_document_indexing_view
 )
 
 
diff --git a/mayan/apps/document_indexing/views.py b/mayan/apps/document_indexing/views.py
index 0e577eb607..7cbdb92e93 100644
--- a/mayan/apps/document_indexing/views.py
+++ b/mayan/apps/document_indexing/views.py
@@ -27,7 +27,7 @@ from .permissions import (
     permission_document_indexing_create, permission_document_indexing_delete,
     permission_document_indexing_edit,
     permission_document_indexing_instance_view,
-    permission_document_indexing_rebuild, permission_document_indexing_view
+    permission_document_indexing_view
 )
 from .tasks import task_rebuild_index
 from .widgets import node_tree
diff --git a/mayan/apps/document_indexing/widgets.py b/mayan/apps/document_indexing/widgets.py
index a55818df2f..35e6763034 100644
--- a/mayan/apps/document_indexing/widgets.py
+++ b/mayan/apps/document_indexing/widgets.py
@@ -27,16 +27,16 @@ def index_instance_item_link(index_instance_item):
 
     if isinstance(index_instance_item, IndexInstanceNode):
         if index_instance_item.index_template_node.link_documents:
-            icon = icon_node_with_documents
+            icon = icon_node_with_documents.render()
         else:
-            icon = icon_index_level_up
+            icon = icon_index_level_up.render()
     else:
-        icon_template = ''
+        icon = ''
 
     return mark_safe(
         '%(icon)s&nbsp;<a href="%(url)s">%(text)s</a>' % {
             'url': index_instance_item.get_absolute_url(),
-            'icon': icon.render(),
+            'icon': icon,
             'text': index_instance_item
         }
     )
diff --git a/mayan/apps/documents/apps.py b/mayan/apps/documents/apps.py
index b936a441b5..812b37662c 100644
--- a/mayan/apps/documents/apps.py
+++ b/mayan/apps/documents/apps.py
@@ -154,6 +154,7 @@ class DocumentsApp(MayanAppConfig):
         ModelEventType.register(
             model=DocumentType, event_types=(
                 event_document_create,
+                event_document_type_created,
                 event_document_type_edited,
             )
         )
diff --git a/mayan/apps/documents/dashboard_widgets.py b/mayan/apps/documents/dashboard_widgets.py
index a951c5a4c3..d570bcf7f7 100644
--- a/mayan/apps/documents/dashboard_widgets.py
+++ b/mayan/apps/documents/dashboard_widgets.py
@@ -79,7 +79,7 @@ class DashboardWidgetDocumentsTypesTotal(DashboardWidgetNumeric):
 class DashboardWidgetDocumentsNewThisMonth(DashboardWidgetNumeric):
     icon_class = icon_dashboard_new_documents_this_month
     label = _('New documents this month')
-    link=reverse_lazy(
+    link = reverse_lazy(
         'statistics:statistic_detail',
         args=('new-documents-per-month',)
     )
@@ -92,7 +92,7 @@ class DashboardWidgetDocumentsNewThisMonth(DashboardWidgetNumeric):
 class DashboardWidgetDocumentsPagesNewThisMonth(DashboardWidgetNumeric):
     icon_class = icon_dashboard_pages_per_month
     label = _('New pages this month')
-    link=reverse_lazy(
+    link = reverse_lazy(
         'statistics:statistic_detail',
         args=('new-document-pages-per-month',)
     )
diff --git a/mayan/apps/documents/views/document_type_views.py b/mayan/apps/documents/views/document_type_views.py
index 831c665d64..d7810b1ca6 100644
--- a/mayan/apps/documents/views/document_type_views.py
+++ b/mayan/apps/documents/views/document_type_views.py
@@ -15,8 +15,7 @@ from common.generics import (
 
 from ..forms import DocumentTypeFilenameForm_create
 from ..icons import (
-    icon_document_type_filename, icon_document_type_filename_create,
-    icon_document_type_setup
+    icon_document_type_filename, icon_document_type_setup
 )
 from ..links import (
     link_document_type_create, link_document_type_filename_create
diff --git a/mayan/apps/documents/views/document_views.py b/mayan/apps/documents/views/document_views.py
index b7b701e7c9..ee6477b7e2 100644
--- a/mayan/apps/documents/views/document_views.py
+++ b/mayan/apps/documents/views/document_views.py
@@ -15,9 +15,8 @@ from common.compressed_files import ZipArchive
 from common.exceptions import ActionError
 from common.generics import (
     ConfirmView, FormView, MultipleObjectConfirmActionView,
-    MultipleObjectConfirmActionView, MultipleObjectFormActionView,
-    SingleObjectDetailView, SingleObjectDownloadView, SingleObjectEditView,
-    SingleObjectListView
+    MultipleObjectFormActionView, SingleObjectDetailView,
+    SingleObjectDownloadView, SingleObjectEditView, SingleObjectListView
 )
 from common.mixins import MultipleInstanceActionMixin
 from common.utils import encapsulate
@@ -90,6 +89,7 @@ class DocumentListView(SingleObjectListView):
         else:
             return queryset
 
+
 class DeletedDocumentDeleteView(ConfirmView):
     extra_context = {
         'title': _('Delete the selected document?')
diff --git a/mayan/apps/mayan_statistics/__init__.py b/mayan/apps/mayan_statistics/__init__.py
index 59c4ee052b..23d1ac4719 100644
--- a/mayan/apps/mayan_statistics/__init__.py
+++ b/mayan/apps/mayan_statistics/__init__.py
@@ -1,5 +1,5 @@
 from __future__ import unicode_literals
 
-from .classes import StatisticLineChart, StatisticNamespace
+from .classes import StatisticLineChart, StatisticNamespace  # NOQA
 
 default_app_config = 'mayan_statistics.apps.StatisticsApp'
diff --git a/mayan/apps/mayan_statistics/apps.py b/mayan/apps/mayan_statistics/apps.py
index acf76212b9..59aba2b30a 100644
--- a/mayan/apps/mayan_statistics/apps.py
+++ b/mayan/apps/mayan_statistics/apps.py
@@ -9,7 +9,7 @@ from common import MayanAppConfig, menu_object, menu_secondary, menu_tools
 
 from navigation import SourceColumn
 
-from .classes import Statistic, StatisticLineChart, StatisticNamespace
+from .classes import StatisticLineChart, StatisticNamespace
 from .links import (
     link_execute, link_namespace_details, link_namespace_list,
     link_statistics, link_view
diff --git a/mayan/apps/mayan_statistics/classes.py b/mayan/apps/mayan_statistics/classes.py
index a1b877b0a9..5f6683b25c 100644
--- a/mayan/apps/mayan_statistics/classes.py
+++ b/mayan/apps/mayan_statistics/classes.py
@@ -1,7 +1,5 @@
 from __future__ import unicode_literals
 
-import json
-
 from django.apps import apps
 from django.utils.encoding import force_text, python_2_unicode_compatible
 
diff --git a/mayan/apps/mayan_statistics/renderers.py b/mayan/apps/mayan_statistics/renderers.py
index 4ca67aee36..91b75779bf 100644
--- a/mayan/apps/mayan_statistics/renderers.py
+++ b/mayan/apps/mayan_statistics/renderers.py
@@ -2,13 +2,6 @@ from __future__ import unicode_literals
 
 import json
 
-from django.apps import apps
-from django.utils.encoding import force_text, python_2_unicode_compatible
-
-from celery.schedules import crontab
-
-from mayan.celery import app
-
 
 class ChartRenderer(object):
     def __init__(self, data):
diff --git a/mayan/apps/metadata/views.py b/mayan/apps/metadata/views.py
index 3594d90771..465999d530 100644
--- a/mayan/apps/metadata/views.py
+++ b/mayan/apps/metadata/views.py
@@ -420,7 +420,6 @@ class DocumentMetadataListView(SingleObjectListView):
             'title': _('Metadata for document: %s') % document,
         }
 
-
     def get_object_list(self):
         return self.get_document().metadata.all()
 
diff --git a/mayan/apps/motd/links.py b/mayan/apps/motd/links.py
index 511992f120..93429e3ba2 100644
--- a/mayan/apps/motd/links.py
+++ b/mayan/apps/motd/links.py
@@ -1,11 +1,8 @@
 from __future__ import absolute_import, unicode_literals
 
-from django.apps import apps
-from django.core.exceptions import PermissionDenied
 from django.utils.translation import ugettext_lazy as _
 
 from navigation import Link, get_cascade_condition
-from permissions import Permission
 
 from .icons import icon_message_create, icon_message_list
 from .permissions import (
diff --git a/mayan/apps/navigation/classes.py b/mayan/apps/navigation/classes.py
index bf9fcef57f..38fe0fa003 100644
--- a/mayan/apps/navigation/classes.py
+++ b/mayan/apps/navigation/classes.py
@@ -259,7 +259,7 @@ class Menu(object):
                 for source in self.non_sorted_sources:
                     if isinstance(resolved_navigation_object, source):
                         unsorted_source = True
-                        break;
+                        break
 
             if sort_results and not unsorted_source:
                 result[0] = sorted(
diff --git a/mayan/apps/navigation/utils.py b/mayan/apps/navigation/utils.py
index f933786ee6..7600d22ad8 100644
--- a/mayan/apps/navigation/utils.py
+++ b/mayan/apps/navigation/utils.py
@@ -2,7 +2,6 @@ from __future__ import absolute_import, unicode_literals
 
 from django.apps import apps
 from django.core.exceptions import PermissionDenied
-from django.utils.translation import ugettext_lazy as _
 
 from permissions import Permission
 
diff --git a/mayan/apps/sources/models.py b/mayan/apps/sources/models.py
index 9dc418537f..16d42d43db 100644
--- a/mayan/apps/sources/models.py
+++ b/mayan/apps/sources/models.py
@@ -36,8 +36,7 @@ from .exceptions import SourceException
 from .literals import (
     DEFAULT_INTERVAL, DEFAULT_POP3_TIMEOUT, DEFAULT_IMAP_MAILBOX,
     DEFAULT_METADATA_ATTACHMENT_NAME, SCANNER_ADF_MODE_CHOICES,
-    SCANNER_ADF_MODE_SIMPLEX, SCANNER_MODE_COLOR, SCANNER_MODE_CHOICES,
-    SCANNER_SOURCE_CHOICES, SCANNER_SOURCE_FLATBED,
+    SCANNER_MODE_COLOR, SCANNER_MODE_CHOICES, SCANNER_SOURCE_CHOICES,
     SOURCE_CHOICES, SOURCE_CHOICE_STAGING, SOURCE_CHOICE_WATCH,
     SOURCE_CHOICE_WEB_FORM, SOURCE_INTERACTIVE_UNCOMPRESS_CHOICES,
     SOURCE_UNCOMPRESS_CHOICES, SOURCE_UNCOMPRESS_CHOICE_N,