diff --git a/django/applications/catmaid/apps.py b/django/applications/catmaid/apps.py
index 7ebbc787b2..8167b3d3a5 100644
--- a/django/applications/catmaid/apps.py
+++ b/django/applications/catmaid/apps.py
@@ -71,7 +71,7 @@ def check_old_version(sender, **kwargs) -> None:
     """Make sure this migration system starts with all South migrations applied,
     in case there are already existing tables."""
     # Only validate after catmaid was migrated
-    if type(sender) != CATMAIDConfig:
+    if not isinstance(sender, CATMAIDConfig):
         return
 
     cursor = connection.cursor()
@@ -174,7 +174,7 @@ def check_client_settings(app_configs, **kwargs):
         logger.info("Force setting instance client settings")
 
     try:
-        if type(instance_settings) == str:
+        if isinstance(instance_settings, str):
             instance_settings = json.loads(instance_settings)
         client.set_instance_settings(instance_settings, force_client_settings)
     except json.JSONDecodeError:
@@ -189,7 +189,7 @@ def check_client_settings(app_configs, **kwargs):
 def validate_environment(sender, **kwargs) -> None:
     """Make sure CATMAID is set up correctly."""
     # Only validate after catmaid was migrated
-    if type(sender) != CATMAIDConfig:
+    if not isinstance(sender, CATMAIDConfig):
         return
 
     sender.validate_projects()
diff --git a/django/applications/catmaid/consumers.py b/django/applications/catmaid/consumers.py
index 025b721bb8..bc0b625a61 100644
--- a/django/applications/catmaid/consumers.py
+++ b/django/applications/catmaid/consumers.py
@@ -22,7 +22,7 @@ def connect(self):
         """
         # Don't do anything, if there is no channels layer.
         if not self.channel_layer:
-            logger.error(f'UpdateConsumer: can\'t handle WebSockets connection, no channels layer')
+            logger.error("UpdateConsumer: can't handle WebSockets connection, no channels layer")
             return
         # Add user to the matching user group
         user = self.scope["user"]
@@ -34,7 +34,7 @@ def disconnect(self, message):
         """
         # Don't do anything, if there is no channels layer.
         if not self.channel_layer:
-            logger.error(f'UpdateConsumer: can\'t handle WebSockets disconnect, no channels layer')
+            logger.error("UpdateConsumer: can't handle WebSockets disconnect, no channels layer")
             return
         user = self.scope["user"]
         async_to_sync(self.channel_layer.group_discard)(get_user_group_name(user.id), self.channel_name)
@@ -44,7 +44,7 @@ def receive(self, *, text_data):
         """
         # Don't do anything, if there is no channels layer.
         if not self.channel_layer:
-            logger.error(f'UpdateConsumer: can\'t handle WebSockets message, no channels layer')
+            logger.error("UpdateConsumer: can't handle WebSockets message, no channels layer")
             return
         user = self.scope["user"]
         text_data_json = json.loads(text_data)
diff --git a/django/applications/catmaid/control/authentication.py b/django/applications/catmaid/control/authentication.py
index 74c0b8b2fd..5be6d8f4ba 100644
--- a/django/applications/catmaid/control/authentication.py
+++ b/django/applications/catmaid/control/authentication.py
@@ -894,7 +894,7 @@ def activate(request:HttpRequest, uidb64, token):
     try:
         uid = force_str(urlsafe_base64_decode(uidb64))
         user = User.objects.get(pk=uid)
-    except(TypeError, ValueError, OverflowError, User.DoesNotExist):
+    except (TypeError, ValueError, OverflowError, User.DoesNotExist):
         user = None
     if user is not None and account_activation_token.check_token(user, token):
         user.is_active = True
diff --git a/django/applications/catmaid/control/client.py b/django/applications/catmaid/control/client.py
index 988ad91f38..267471247d 100644
--- a/django/applications/catmaid/control/client.py
+++ b/django/applications/catmaid/control/client.py
@@ -220,7 +220,7 @@ def put(self, request:Request, name:Optional[int]=None, format=None) -> Response
 
         # We expect also an actual object, not a single string or number, which
         # is represented as a dict in Python.
-        if type(value) != dict:
+        if not isinstance(value, dict):
             raise ValidationError(f'Data is of type "{type(value)}", but '
                     f'expected an object: {str(value)}')
 
@@ -336,7 +336,7 @@ def set_instance_settings(settings, force=False):
     settings familiy, e.g. "neuron-name-service" and the value is the respective
     settings data.
     """
-    if type(settings) != dict:
+    if not isinstance(settings, dict):
         raise ValueError("Settings needs to be a dictionry")
 
     data_store = ClientDatastore.objects.get(name='settings')
diff --git a/django/applications/catmaid/control/nat/r.py b/django/applications/catmaid/control/nat/r.py
index 16a24ba773..cae9d93663 100644
--- a/django/applications/catmaid/control/nat/r.py
+++ b/django/applications/catmaid/control/nat/r.py
@@ -661,7 +661,7 @@ def create_dps_data_cache(project_id, object_type, tangent_neighbors=20,
                 '.parallel': parallel,
             })
             # Make sure unneeded R objects are deleted
-            del(objects)
+            del objects
             gc.collect()
             objects = simplified_objects
 
@@ -674,7 +674,7 @@ def create_dps_data_cache(project_id, object_type, tangent_neighbors=20,
                     'OmitFailures': omit_failures,
                 })
 
-        del(objects)
+        del objects
 
         # Save cache to disk
         logger.debug(f'Storing skeleton cache with {len(objects_dps)} entries: {cache_path}')
@@ -836,7 +836,7 @@ def nblast(project_id, user_id, config_id, query_object_ids, target_object_ids,
                 # TODO: There must be a simler way to extract non-NA values only
                 query_object_id_str = rinterface.StrSexpVector(list(map(str, query_object_ids)))
                 query_cache_objects_dps = skeleton_cache.rx(query_object_id_str)
-                non_na_ids = list(filter(lambda x: type(x) == str,
+                non_na_ids = list(filter(lambda x: isinstance(x, str),
                         list(base.names(query_cache_objects_dps))))
                 cache_typed_query_object_ids = non_na_ids
                 query_cache_objects_dps = rnat.subset_neuronlist(
@@ -897,7 +897,7 @@ def nblast(project_id, user_id, config_id, query_object_ids, target_object_ids,
                 # TODO: There must be a simler way to extract non-NA values only
                 query_object_id_str = rinterface.StrSexpVector(list(map(str, query_object_ids)))
                 query_cache_objects_dps = pointcloud_cache.rx(query_object_id_str) # type: ignore # not provable that cache will be initialised
-                non_na_ids = list(filter(lambda x: type(x) == str,
+                non_na_ids = list(filter(lambda x: isinstance(x, str),
                         list(base.names(query_cache_objects_dps))))
                 query_cache_objects_dps = rnat.subset_neuronlist(
                         query_cache_objects_dps, rinterface.StrSexpVector(non_na_ids))
@@ -1000,7 +1000,7 @@ def nblast(project_id, user_id, config_id, query_object_ids, target_object_ids,
                     # TODO: There must be a simler way to extract non-NA values only
                     target_object_id_str = rinterface.StrSexpVector(list(map(str, target_object_ids)))
                     target_cache_objects_dps = skeleton_cache.rx(target_object_id_str)
-                    non_na_ids = list(filter(lambda x: type(x) == str,
+                    non_na_ids = list(filter(lambda x: isinstance(x, str),
                             list(base.names(target_cache_objects_dps))))
                     cache_typed_target_object_ids = non_na_ids
                     target_cache_objects_dps = rnat.subset_neuronlist(
@@ -1062,7 +1062,7 @@ def nblast(project_id, user_id, config_id, query_object_ids, target_object_ids,
                     # TODO: There must be a simler way to extract non-NA values only
                     target_object_id_str = rinterface.StrSexpVector(list(map(str, target_object_ids)))
                     target_cache_objects_dps = pointcloud_cache.rx(target_object_id_str) # type: ignore
-                    non_na_ids = list(filter(lambda x: type(x) == str,
+                    non_na_ids = list(filter(lambda x: isinstance(x, str),
                             list(base.names(target_cache_objects_dps))))
                     target_cache_objects_dps = rnat.subset_neuronlist(
                             target_cache_objects_dps, rinterface.StrSexpVector(non_na_ids))
@@ -1633,7 +1633,7 @@ def neuronlist_for_skeletons(project_id, skeleton_ids, omit_failures=False,
             })
     print(f"Converted {len(objects)}/{len(skeleton_ids)} neurons")
 
-    del(cs_r)
+    del cs_r
     gc.collect()
 
     return objects
diff --git a/django/applications/catmaid/control/node.py b/django/applications/catmaid/control/node.py
index fe2d7c9641..27edda2a65 100644
--- a/django/applications/catmaid/control/node.py
+++ b/django/applications/catmaid/control/node.py
@@ -1432,7 +1432,7 @@ def get_tuples(self, params, project_id, explicit_treenode_ids,
 def get_node_provider_configs():
     """Get a list of specified node provider configurationss."""
     configs = settings.NODE_PROVIDERS
-    if type(configs) == str:
+    if isinstance(configs, str):
         configs = [configs]
     return configs
 
@@ -1440,7 +1440,7 @@ def get_node_provider_configs():
 def get_configured_node_providers(provider_entries, connection=None,
         enabled_only=False) -> List:
     node_providers = []
-    if type(provider_entries) == str:
+    if isinstance(provider_entries, str):
         provider_entries = [provider_entries]
     for entry in provider_entries:
         options:Dict = {}
diff --git a/django/applications/catmaid/control/similarity.py b/django/applications/catmaid/control/similarity.py
index df45286df8..8b23e16e2f 100644
--- a/django/applications/catmaid/control/similarity.py
+++ b/django/applications/catmaid/control/similarity.py
@@ -338,16 +338,16 @@ def put(self, request:Request, project_id) -> Response:
         if matching_subset:
             matching_subset = json.loads(matching_subset)
 
-            if type(matching_subset) != list:
+            if not isinstance(matching_subset, list):
                 raise ValueError("Expected matching_subset to be a list")
 
             for subset in matching_subset:
-                if type(subset) != list:
+                if not isinstance(subset, list):
                     raise ValueError("Expected all matching_subset elements to be list")
                 for element in subset:
-                    if type(element) != list or len(element) != 2:
+                    if not isinstance(element, list) or len(element) != 2:
                         raise ValueError("Expeceted subset elements to be lists with two elements")
-                    if type(element[0]) not in (int, list) or type(element[1]) != int:
+                    if type(element[0]) not in (int, list) or not isinstance(element[1], int):
                         raise ValueError("Expected subset selements to consist of ints or lists of ints")
 
         # Load and store point sets, if there are any.
diff --git a/django/applications/catmaid/control/skeletonexport.py b/django/applications/catmaid/control/skeletonexport.py
index d6a99b6dcb..76ad4c2cbc 100644
--- a/django/applications/catmaid/control/skeletonexport.py
+++ b/django/applications/catmaid/control/skeletonexport.py
@@ -668,7 +668,7 @@ def _compact_skeleton(project_id, skeleton_id, with_connectors=True,
                 SELECT relation_name, id FROM relation WHERE project_id=%(project_id)s
             """, {
                 'project_id': project_id,
-            })
+        })
         relations = dict(cursor.fetchall())
 
     if with_connectors:
diff --git a/django/applications/catmaid/control/textlabel.py b/django/applications/catmaid/control/textlabel.py
index db9639616a..2831b7c923 100644
--- a/django/applications/catmaid/control/textlabel.py
+++ b/django/applications/catmaid/control/textlabel.py
@@ -175,14 +175,14 @@ def textlabels(request:HttpRequest, project_id=None) -> JsonResponse:
         response_on_error = 'Failed to format output'
         for tl in textlabels:
             tl['colour'] = {'r': tl['r'], 'g': tl['g'], 'b': tl['b'], 'a': tl['a']}
-            del(tl['r'])
-            del(tl['g'])
-            del(tl['b'])
-            del(tl['a'])
+            del tl['r']
+            del tl['g']
+            del tl['b']
+            del tl['a']
             tl['location'] = {'x': tl['x'], 'y': tl['y'], 'z': tl['z']}
-            del(tl['x'])
-            del(tl['y'])
-            del(tl['z'])
+            del tl['x']
+            del tl['y']
+            del tl['z']
             if tl['scaling']:
                 tl['scaling'] = 1
             else:
diff --git a/django/applications/catmaid/management/commands/catmaid_export_data.py b/django/applications/catmaid/management/commands/catmaid_export_data.py
index 427ae2cd5c..b67d5118d6 100644
--- a/django/applications/catmaid/management/commands/catmaid_export_data.py
+++ b/django/applications/catmaid/management/commands/catmaid_export_data.py
@@ -989,7 +989,7 @@ def collect_data(self):
         seen_deep_links = set()
         if self.export_public_deep_links:
             deep_links = DeepLink.objects.filter(project_id=self.project.id, is_public=True)
-            seen_deep_links.update([l.id for l in deep_links])
+            seen_deep_links.update([link.id for link in deep_links])
             logger.info(f'Exporting {len(deep_links)} public deep links')
             self.to_serialize.append(deep_links)
 
@@ -998,7 +998,7 @@ def collect_data(self):
             deep_links = DeepLink.objects.filter(project_id=self.project.id, is_exportable=True)
             n_exportable_deep_links = len(deep_links)
             deep_links = list(filter(lambda x: x.id not in seen_deep_links, deep_links))
-            seen_deep_links.update([l.id for l in deep_links])
+            seen_deep_links.update([link.id for link in deep_links])
             logger.info(f'Exporting {n_exportable_deep_links} exportable deep links ({len(deep_links)} are not already prev. included)')
             self.to_serialize.append(deep_links)
 
diff --git a/django/applications/catmaid/management/commands/catmaid_import_from_trakem2.py b/django/applications/catmaid/management/commands/catmaid_import_from_trakem2.py
index 12d3bf074a..15a8b6b7a0 100644
--- a/django/applications/catmaid/management/commands/catmaid_import_from_trakem2.py
+++ b/django/applications/catmaid/management/commands/catmaid_import_from_trakem2.py
@@ -116,7 +116,7 @@ def __init__(self, t, r, transformer, side:SynapseSides, parent_neuron_id:int,
                 if type(d) in (TrakEM2.AreaTree, TrakEM2.AreaList)]
 
         if len(self.displayables) > 1:
-            arealists = list(filter(lambda x: type(x) == TrakEM2.AreaList, self.displayables))
+            arealists = list(filter(lambda x: isinstance(x, TrakEM2.AreaList), self.displayables))
             n_arealists = len(arealists)
             if n_arealists == 1:
                 log('Can only assign connector node to a single displayable, '
diff --git a/django/applications/catmaid/state.py b/django/applications/catmaid/state.py
index bde39c3f29..443ea7cbf0 100644
--- a/django/applications/catmaid/state.py
+++ b/django/applications/catmaid/state.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 import decimal
 from functools import reduce
 import json
@@ -216,7 +214,7 @@ def collect_state_checks(node_id, state, cursor, node=False,
         if not all(has_only_truthy_values(e) for e in child_nodes):
             raise ValueError("No valid state provided, invalid children")
 
-        if type(children) == bool:
+        if isinstance(children, bool):
             state_checks.append(make_all_children_query(
                 [int(c[0]) for c in child_nodes], node_id))
         state_checks.extend(StateCheck(SQL.was_edited, (c[0], c[1], c[1])) for c in child_nodes)
@@ -331,7 +329,7 @@ def lock_nodes(node_ids, cursor) -> None:
         raise ValueError("No nodes to lock")
 
 def is_disabled(state) -> bool:
-    return state and type(state) == dict and state.get('nocheck') is True
+    return state and isinstance(state, dict) and state.get('nocheck') is True
 
 def make_nocheck_state(parsed=False):
     """Get a state representation that causes skipping of actual state checks.
diff --git a/django/applications/catmaid/templatetags/data_view_config.py b/django/applications/catmaid/templatetags/data_view_config.py
index 572d96336c..fbbf1e8189 100644
--- a/django/applications/catmaid/templatetags/data_view_config.py
+++ b/django/applications/catmaid/templatetags/data_view_config.py
@@ -100,7 +100,7 @@ def render(self, context):
                 tag = t.resolve(context)
                 if not tag:
                     continue
-                elif type(tag) == list:
+                elif isinstance(tag, list):
                     for subtag in tag:
                         current_tags.append(subtag)
                 else:
diff --git a/django/applications/catmaid/tests/apis/test_skeletons.py b/django/applications/catmaid/tests/apis/test_skeletons.py
index 996e9e82af..0d66ad23a0 100644
--- a/django/applications/catmaid/tests/apis/test_skeletons.py
+++ b/django/applications/catmaid/tests/apis/test_skeletons.py
@@ -980,8 +980,8 @@ def test_export_skeleton_reviews(self):
 
         skeleton_id = 235
 
-        def first_element(l):
-            return l[0]
+        def first_element(node_entry):
+            return node_entry[0]
 
         def sort_json_nodes(node_result):
             for k,v in expected_result.items():
diff --git a/django/applications/catmaid/tests/common.py b/django/applications/catmaid/tests/common.py
index 26f3f69c89..6a4d05400e 100644
--- a/django/applications/catmaid/tests/common.py
+++ b/django/applications/catmaid/tests/common.py
@@ -110,12 +110,12 @@ def fake_authentication(self):
         self.client.login(username='temporary', password='temporary')
 
 
-def round_list(l, digits=6):
+def round_list(value_list, digits=6):
     """Round floating point values in a list recursively to the specified number
     of digits.
     """
     new_list = []
-    for v in l:
+    for v in value_list:
         v_type = type(v)
         if v_type == float:
             new_list.append(round(v, digits))
diff --git a/django/applications/catmaid/tests/test_import_export.py b/django/applications/catmaid/tests/test_import_export.py
index 549a95ce4e..d5300faac4 100644
--- a/django/applications/catmaid/tests/test_import_export.py
+++ b/django/applications/catmaid/tests/test_import_export.py
@@ -331,12 +331,12 @@ def test_import_export_projects(self):
         def strip_ids(d):
             """ Recursively, strip all 'id' fields of dictionaries.
             """
-            if type(d) == dict:
+            if isinstance(d, dict):
                 if 'id' in d:
                     d.pop('id')
                 for _,v in d.items():
                     strip_ids(v)
-            if type(d) == list:
+            if isinstance(d, list):
                 for v in d:
                     strip_ids(v)
 
@@ -350,7 +350,7 @@ def test_result(result):
                 # results in tuples).
                 if 'project' in p:
                     if 'stacks' in p['project']:
-                        if type(p['project']['stacks']) == tuple:
+                        if isinstance(p['project']['stacks'], tuple):
                             p['project']['stacks'] = list(p['project']['stacks'])
                 self.assertDictEqual(cp, p)
 
@@ -358,7 +358,7 @@ def test_result(result):
 
         def parse_list(d):
             for k in d:
-                if type(d[k]) == tuple:
+                if isinstance(d[k], tuple):
                     d[k] = list(d[k])
             return d
 
diff --git a/django/lib/custom_swagger_schema.py b/django/lib/custom_swagger_schema.py
index d705bd37f2..9f9832f2d4 100644
--- a/django/lib/custom_swagger_schema.py
+++ b/django/lib/custom_swagger_schema.py
@@ -58,7 +58,7 @@ def get_link(self, path, method, base_url):
         # a block quote (due to Python comments being indented).
         _method_desc = '\n'.join(line.strip() for line in _method_desc.splitlines())
 
-        if yaml_doc and type(yaml_doc) != str:
+        if yaml_doc and not isinstance(yaml_doc, str):
             params = yaml_doc.get('parameters', [])
 
             params_type = type(params)