diff --git a/mdb/admin.py b/mdb/admin.py
index 05801fe..d760063 100644
--- a/mdb/admin.py
+++ b/mdb/admin.py
@@ -3,9 +3,10 @@ import ipaddress
 from django.contrib import admin, messages
 from django.db.models import Count
 from mdb.forms import InterfaceForm
-from mdb.models import Ip6Address, Interface, Ip4Address, DhcpOption, DhcpCustomField, DomainSrvRecord, DomainTxtRecord, \
-    DomainCnameRecord, DomainARecord, Domain, Host, Ip4Subnet, Ip6Subnet, Nameserver, MailExchange, OperatingSystem, \
-    HostType, DhcpConfig, DomainAAAARecord
+from mdb.models import (
+    Ip6Address, Interface, Ip4Address, DhcpOption, DhcpCustomField, DomainSrvRecord, DomainTxtRecord,
+    DomainCnameRecord, DomainARecord, Domain, Host, Ip4Subnet, Ip6Subnet, Nameserver, MailExchange, OperatingSystem,
+    HostType, DhcpConfig, DomainAAAARecord)
 
 
 class Ip6AddressInline(admin.TabularInline):
@@ -37,22 +38,22 @@ class HostAdmin(admin.ModelAdmin):
             'fields': ('owner', 'location', 'description')
         }),
         ('Hardware and Software Information', {
-            'fields': (('hostname', 'host_type'), ('pxe_key', 'pxe_installable'), ('brand', 'model'), 'serial_number', ('operating_system', 'virtual'))
+            'fields': (
+                ('hostname', 'host_type'),
+                ('pxe_key', 'pxe_installable'),
+                ('brand', 'model'),
+                'serial_number',
+                ('operating_system', 'virtual'))
         }),
-        # FIXME: Not in use
-        # ('Domain and Kerberos Information', {
-        #     'description': 'If this host is a member of the LDAP domain, you need to tick the request kerberos principal checkbox. A principal will then be created for the host.',
-        #     'classes': ['collapse'],
-        #     'fields': ('request_kerberos_principal', 'kerberos_principal_created',
-        #                ('kerberos_principal_name', 'kerberos_principal_created_date'))
-        # }),
     )
     actions = ['set_installable']
 
+    @staticmethod
     def mac_addresses(self, host):
         addresses = host.interface_set.filter(macaddr__isnull=False).values_list('macaddr', flat=True)
         return ", ".join(addresses)
 
+    @staticmethod
     def ip_addresses(self, host):
         addresses = host.interface_set.filter(ip4address__isnull=False).values_list('ip4address__address', flat=True)
         return ", ".join(addresses)
@@ -69,7 +70,8 @@ class HostAdmin(admin.ModelAdmin):
 
     ipv6_enabled.boolean = True
 
-    def _get_host_warning_message(self, host, ifs):
+    @staticmethod
+    def _get_host_warning_message(host, ifs):
         ifs_str = ', '.join([_if.name for _if in ifs])
         return 'Host {} might not be installable since interface(s) {} has no IP set.'.format(host, ifs_str)
 
diff --git a/mdb/api/views.py b/mdb/api/views.py
index dd9ec89..20e8966 100644
--- a/mdb/api/views.py
+++ b/mdb/api/views.py
@@ -15,6 +15,6 @@ class HostPXEValidate(APIView):
 
         serializer.is_valid(raise_exception=True)
 
-        host = serializer.save()  # sets Host.pxe_installable=False
+        serializer.save()  # sets Host.pxe_installable=False
 
         return Response({'valid_pxe_key': True})
diff --git a/mdb/apps.py b/mdb/apps.py
index 159d9aa..6a0f310 100644
--- a/mdb/apps.py
+++ b/mdb/apps.py
@@ -7,4 +7,4 @@ class MdbAppConfig(AppConfig):
 
     def ready(self):
         # all models are loaded, now attach signals
-        import mdb.signals
\ No newline at end of file
+        import mdb.signals  # noqa
diff --git a/mdb/models.py b/mdb/models.py
index adf5ed7..0b9b470 100644
--- a/mdb/models.py
+++ b/mdb/models.py
@@ -319,7 +319,7 @@ class Ip6Subnet(models.Model):
         # content += "$ORIGIN " + ".".join(network.exploded.replace(":","")[:16])[::-1] + ".ip6.arpa.\n"
 
         for addr in self.ip6address_set.all():
-            #if addr.interface_set.count() == 0: continue
+            # if addr.interface_set.count() == 0: continue
 
             if addr.interface.domain is None:
                 continue
diff --git a/mdb/tests.py b/mdb/tests.py
index 8a48d96..d4b27eb 100644
--- a/mdb/tests.py
+++ b/mdb/tests.py
@@ -68,13 +68,13 @@ class RunManagementCommands(TestCase):
     fixtures = ['test_data']
 
     def test_zone_sync(self):
-        expected_zone_file = ''
+        # expected_zone_file = ''
         with io.BytesIO() as f:
             call_command('zone-sync', debug=True, stdout=f)
         # TODO check expected_zone_file
 
     def test_dhcp_sync(self):
-        expected_dhcp_file = ''
+        # expected_dhcp_file = ''
         with io.BytesIO() as f:
             call_command('dhcp-sync', stdout=f)
         # TODO check expected_dhcp_file
diff --git a/mdb/utils.py b/mdb/utils.py
index 7f16f3d..c930bfc 100644
--- a/mdb/utils.py
+++ b/mdb/utils.py
@@ -17,7 +17,7 @@ def format_domain_serial_and_add_one(serial):
         """ The serial contains todays date, just update it. """
         try:
             number = int(res[0])
-        except:
+        except ValueError:
             number = 1
         if number >= 99:
             """ This is bad... Just keep the number on 99.
@@ -31,4 +31,4 @@ def format_domain_serial_and_add_one(serial):
     else:
         """ Just return the first serial for today. """
         return "%4d%02d%02d%02d" % \
-            (today.year, today.month, today.day, 1)
\ No newline at end of file
+            (today.year, today.month, today.day, 1)
diff --git a/mdbsite/settings.py b/mdbsite/settings.py
index 23c99d7..ee78e03 100644
--- a/mdbsite/settings.py
+++ b/mdbsite/settings.py
@@ -116,7 +116,7 @@ SUIT_CONFIG = {
     ),
 
     # misc
-    'LIST_PER_PAGE': 30
+    'LIST_PER_PAGE': 35
 }
 REST_FRAMEWORK = {
     'DEFAULT_PERMISSION_CLASSES': ('rest_framework.permissions.IsAuthenticated',),