diff --git a/mautrix_appservice/appservice.py b/mautrix_appservice/appservice.py
index 70d883b3..6cf35da0 100644
--- a/mautrix_appservice/appservice.py
+++ b/mautrix_appservice/appservice.py
@@ -106,7 +106,7 @@ class AppService:
 
         try:
             response = self.query_user(user_id)
-        except:
+        except Exception:
             self.log.exception("Exception in user query handler")
             return web.Response(status=500)
 
@@ -122,7 +122,7 @@ class AppService:
 
         try:
             response = self.query_alias(alias)
-        except:
+        except Exception:
             self.log.exception("Exception in alias query handler")
             return web.Response(status=500)
 
@@ -164,7 +164,7 @@ class AppService:
         for handler in self.event_handlers:
             try:
                 handler(event)
-            except:
+            except Exception:
                 self.log.exception("Exception in Matrix event handler")
 
     def matrix_event_handler(self, func):
diff --git a/mautrix_appservice/intent_api.py b/mautrix_appservice/intent_api.py
index a578d45e..67c7d7ff 100644
--- a/mautrix_appservice/intent_api.py
+++ b/mautrix_appservice/intent_api.py
@@ -25,11 +25,8 @@ from matrix_client.errors import MatrixRequestError
 class HTTPAPI(MatrixHttpApi):
     def __init__(self, base_url, domain=None, bot_mxid=None, token=None, identity=None, log=None,
                  state_store=None):
-        self.base_url = base_url
+        super().__init__(base_url, token, identity)
         self.domain = domain
-        self.token = token
-        self.identity = identity
-        self.txn_id = 0
         self.bot_mxid = bot_mxid
         self.intent_log = log.getChild("intent")
         self.log = log.getChild("api")
@@ -51,25 +48,17 @@ class HTTPAPI(MatrixHttpApi):
     def intent(self, user):
         return IntentAPI(user, self.user(user), self, self.state_store, self.intent_log)
 
-    def _send(self, method, path, content=None, query_params={}, headers={},
+    def _send(self, method, path, content=None, query_params=None, headers=None,
               api_path="/_matrix/client/r0"):
         if not query_params:
             query_params = {}
         query_params["user_id"] = self.identity
         log_content = content if not isinstance(content, bytes) else f"<{len(content)} bytes>"
         self.log.debug("%s %s %s", method, path, log_content)
-        return super()._send(method, path, content, query_params, headers, api_path=api_path)
+        return super()._send(method, path, content, query_params, headers or {}, api_path=api_path)
 
     def create_room(self, alias=None, is_public=False, name=None, topic=None, is_direct=False,
-                    invitees=(), initial_state=[]):
-        """Perform /createRoom.
-        Args:
-            alias (str): Optional. The room alias name to set for this room.
-            is_public (bool): Optional. The public/private visibility.
-            name (str): Optional. The name for the room.
-            topic (str): Optional. The topic for the room.
-            invitees (list<str>): Optional. The list of user IDs to invite.
-        """
+                    invitees=(), initial_state=None):
         content = {
             "visibility": "public" if is_public else "private"
         }
@@ -106,9 +95,10 @@ class HTTPAPI(MatrixHttpApi):
 
 class ChildHTTPAPI(HTTPAPI):
     def __init__(self, user, parent):
-        self.identity = user
-        self.token = parent.token
         self.base_url = parent.base_url
+        self.token = parent.token
+        self.identity = user
+        self.validate_cert = True
         self.validate_cert = parent.validate_cert
         self.log = parent.log
         self.domain = parent.domain
@@ -133,7 +123,7 @@ def matrix_error_code(err):
     try:
         data = json.loads(err.content)
         return data["errcode"]
-    except:
+    except Exception:
         return err.content
 
 
@@ -189,10 +179,10 @@ class IntentAPI:
     # region Room actions
 
     def create_room(self, alias=None, is_public=False, name=None, topic=None, is_direct=False,
-                    invitees=(), initial_state=[]):
+                    invitees=(), initial_state=None):
         self.ensure_registered()
         return self.client.create_room(alias, is_public, name, topic, is_direct, invitees,
-                                       initial_state)
+                                       initial_state or {})
 
     def invite(self, room_id, user_id):
         self.ensure_joined(room_id)
@@ -251,31 +241,31 @@ class IntentAPI:
     def send_emote(self, room_id, text, html=None):
         return self.send_text(room_id, text, html, "m.emote")
 
-    def send_image(self, room_id, url, info={}, text=None):
-        return self.send_file(room_id, url, info, text, "m.image")
+    def send_image(self, room_id, url, info=None, text=None):
+        return self.send_file(room_id, url, info or {}, text, "m.image")
 
-    def send_file(self, room_id, url, info={}, text=None, type="m.file"):
+    def send_file(self, room_id, url, info=None, text=None, file_type="m.file"):
         return self.send_message(room_id, {
-            "msgtype": type,
+            "msgtype": file_type,
             "url": url,
             "body": text or "Uploaded file",
-            "info": info,
+            "info": info or {},
         })
 
-    def send_text(self, room_id, text, html=None, type="m.text"):
+    def send_text(self, room_id, text, html=None, msgtype="m.text"):
         if html:
             if not text:
                 text = html
             return self.send_message(room_id, {
                 "body": text,
-                "msgtype": type,
+                "msgtype": msgtype,
                 "format": "org.matrix.custom.html",
                 "formatted_body": html or text,
             })
         else:
             return self.send_message(room_id, {
                 "body": text,
-                "msgtype": type,
+                "msgtype": msgtype,
             })
 
     def send_message(self, room_id, body):
@@ -290,15 +280,15 @@ class IntentAPI:
         self.ensure_joined(room_id)
         return self.client.kick_user(room_id, user_id, message)
 
-    def send_event(self, room_id, type, body, txn_id=None):
+    def send_event(self, room_id, event_type, body, txn_id=None):
         self.ensure_joined(room_id)
-        self._ensure_has_power_level_for(room_id, type)
-        return self.client.send_message_event(room_id, type, body, txn_id)
+        self._ensure_has_power_level_for(room_id, event_type)
+        return self.client.send_message_event(room_id, event_type, body, txn_id)
 
-    def send_state_event(self, room_id, type, body, state_key=""):
+    def send_state_event(self, room_id, event_type, body, state_key=""):
         self.ensure_joined(room_id)
-        self._ensure_has_power_level_for(room_id, type)
-        return self.client.send_state_event(room_id, type, body, state_key)
+        self._ensure_has_power_level_for(room_id, event_type)
+        return self.client.send_state_event(room_id, event_type, body, state_key)
 
     def join_room(self, room_id):
         return self.ensure_joined(room_id, ignore_cache=True)
@@ -359,7 +349,8 @@ class IntentAPI:
         elif not self.bot:
             self.log.warning(
                 f"Power level of {self.mxid} is not enough for {event_type} in {room_id}")
-            # raise IntentError(f"Power level of {self.mxid} is not enough for {event_type} in {room_id}")
+            # raise IntentError(f"Power level of {self.mxid} is not enough"
+            #                  + f"for {event_type} in {room_id}")
             return
         # TODO implement
 
diff --git a/mautrix_appservice/state_store.py b/mautrix_appservice/state_store.py
index a2c9bb37..03cab88a 100644
--- a/mautrix_appservice/state_store.py
+++ b/mautrix_appservice/state_store.py
@@ -42,13 +42,13 @@ class StateStore:
     def load(self, file):
         if isinstance(file, str):
             try:
-                input = open(file, "r")
+                input_source = open(file, "r")
             except FileNotFoundError:
                 return
         else:
-            input = file
+            input_source = file
 
-        data = json.load(input)
+        data = json.load(input_source)
         if "registrations" in data:
             self.registrations = set(data["registrations"])
         if "memberships" in data:
@@ -57,7 +57,7 @@ class StateStore:
             self.power_levels = data["power_levels"]
 
         if isinstance(file, str):
-            input.close()
+            input_source.close()
 
     def _autosave(self):
         if self.autosave_file:
@@ -104,7 +104,7 @@ class StateStore:
         return has >= required
 
     def set_power_level(self, room, user, level):
-        if not room in self.power_levels:
+        if room not in self.power_levels:
             self.power_levels[room] = {
                 "users": {},
                 "events": {},
diff --git a/mautrix_telegram/commands.py b/mautrix_telegram/commands.py
index e0499ae4..e3577ac4 100644
--- a/mautrix_telegram/commands.py
+++ b/mautrix_telegram/commands.py
@@ -47,7 +47,7 @@ class CommandHandler:
         with self.handler(sender, room, command, args, is_management, is_portal) as handle_command:
             try:
                 handle_command(self, sender, args)
-            except:
+            except Exception:
                 self.reply("Fatal error while handling command. Check logs for more details.")
                 self.log.exception(f"Fatal error handling command "
                                    + f"'$cmdprefix {command} {''.join(args)}' from {sender.mxid}")
@@ -158,7 +158,7 @@ class CommandHandler:
             }
             return self.reply("Your account has two-factor authentication."
                               "Please send your password here.")
-        except:
+        except Exception:
             self.log.exception()
             return self.reply("Unhandled exception while sending code."
                               "Check console for more details.")
@@ -177,7 +177,7 @@ class CommandHandler:
             return self.reply(f"Successfully logged in as @{user.username}")
         except PasswordHashInvalidError:
             return self.reply("Incorrect password.")
-        except:
+        except Exception:
             self.log.exception()
             return self.reply("Unhandled exception while sending password. "
                               "Check console for more details.")
@@ -199,9 +199,9 @@ class CommandHandler:
             return self.reply("**Usage:** `$cmdprefix+sp search [-r|--remote] <query>")
         elif not sender.logged_in:
             return self.reply("This command requires you to be logged in.")
-        force_remote = False
+        # force_remote = False
         if args[0] in {"-r", "--remote"}:
-            force_remote = True
+            # force_remote = True
             args.pop(0)
         query = " ".join(args)
         if len(query) < 5:
@@ -298,7 +298,7 @@ class CommandHandler:
         if arg.startswith("joinchat/"):
             invite_hash = arg[len("joinchat/"):]
             try:
-                check = sender.client(CheckChatInviteRequest(invite_hash))
+                sender.client(CheckChatInviteRequest(invite_hash))
             except InviteHashInvalidError:
                 return self.reply("Invalid invite link.")
             except InviteHashExpiredError:
diff --git a/mautrix_telegram/config.py b/mautrix_telegram/config.py
index f766deda..f2f81426 100644
--- a/mautrix_telegram/config.py
+++ b/mautrix_telegram/config.py
@@ -14,16 +14,16 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
-import ruamel.yaml
+from ruamel.yaml import YAML
 import random
 import string
 
-yaml = ruamel.yaml.YAML()
+yaml = YAML()
 
 
 class DictWithRecursion:
-    def __init__(self, data={}):
-        self._data = data
+    def __init__(self, data=None):
+        self._data = data or {}
 
     def _recursive_get(self, data, key, default_value):
         if '.' in key:
diff --git a/mautrix_telegram/formatter.py b/mautrix_telegram/formatter.py
index ca6ba027..004cea3a 100644
--- a/mautrix_telegram/formatter.py
+++ b/mautrix_telegram/formatter.py
@@ -53,12 +53,12 @@ class MatrixParser(HTMLParser):
         self._open_tags.appendleft(tag)
         self._open_tags_meta.appendleft(0)
         attrs = dict(attrs)
-        EntityType = None
+        entity_type = None
         args = {}
         if tag == "strong" or tag == "b":
-            EntityType = MessageEntityBold
+            entity_type = MessageEntityBold
         elif tag == "em" or tag == "i":
-            EntityType = MessageEntityItalic
+            entity_type = MessageEntityItalic
         elif tag == "code":
             try:
                 pre = self._building_entities["pre"]
@@ -67,9 +67,9 @@ class MatrixParser(HTMLParser):
                 except KeyError:
                     pass
             except KeyError:
-                EntityType = MessageEntityCode
+                entity_type = MessageEntityCode
         elif tag == "pre":
-            EntityType = MessageEntityPre
+            entity_type = MessageEntityPre
             args["language"] = ""
         elif tag == "a":
             try:
@@ -86,13 +86,13 @@ class MatrixParser(HTMLParser):
                     if not user:
                         return
                 if user.username:
-                    EntityType = MessageEntityMention
+                    entity_type = MessageEntityMention
                     url = f"@{user.username}"
                 else:
-                    EntityType = MessageEntityMentionName
+                    entity_type = MessageEntityMentionName
                     args["user_id"] = user.tgid
-            elif reply and self._user_id and (
-                len(self.entities) == 0 and len(self._building_entities) == 0):
+            elif reply and self._user_id and (len(self.entities) == 0
+                                              and len(self._building_entities) == 0):
                 room_id = reply.group(1)
                 message_id = reply.group(2)
                 message = DBMessage.query.filter(DBMessage.mxid == message_id
@@ -100,25 +100,25 @@ class MatrixParser(HTMLParser):
                                                  and DBMessage.user == self._user_id).one_or_none()
                 if not message:
                     return
-                EntityType = MessageEntityReply
+                entity_type = MessageEntityReply
                 args["msg_id"] = message.tgid
                 self._building_reply = True
                 url = None
             elif url.startswith("mailto:"):
                 url = url[len("mailto:"):]
-                EntityType = MessageEntityEmail
+                entity_type = MessageEntityEmail
             else:
                 if self.get_starttag_text() == url:
-                    EntityType = MessageEntityUrl
+                    entity_type = MessageEntityUrl
                 else:
-                    EntityType = MessageEntityTextUrl
+                    entity_type = MessageEntityTextUrl
                     args["url"] = url
                     url = None
             self._open_tags_meta.popleft()
             self._open_tags_meta.appendleft(url)
 
-        if EntityType and tag not in self._building_entities:
-            self._building_entities[tag] = EntityType(offset=len(self.text), length=0, **args)
+        if entity_type and tag not in self._building_entities:
+            self._building_entities[tag] = entity_type(offset=len(self.text), length=0, **args)
 
     def _list_depth(self):
         depth = 0
@@ -183,7 +183,7 @@ def matrix_to_telegram(html, user_id=None):
         parser = MatrixParser(user_id)
         parser.feed(html)
         return parser.text, parser.entities
-    except:
+    except Exception:
         log.exception("Failed to convert Matrix format:\nhtml=%s", html)
 
 
@@ -197,18 +197,20 @@ def telegram_event_to_matrix(evt, source):
     if evt.fwd_from:
         if not html:
             html = escape(text)
-        id = evt.fwd_from.from_id
-        user = u.User.get_by_tgid(id)
+        from_id = evt.fwd_from.from_id
+        user = u.User.get_by_tgid(from_id)
         if user:
             fwd_from = f"<a href='https://matrix.to/#/{user.mxid}'>{user.mxid}</a>"
         else:
-            puppet = p.Puppet.get(id, create=False)
+            puppet = p.Puppet.get(from_id, create=False)
             if puppet and puppet.displayname:
                 fwd_from = f"<a href='https://matrix.to/#/{puppet.mxid}'>{puppet.displayname}</a>"
             else:
-                user = source.client.get_entity(id)
+                user = source.client.get_entity(from_id)
                 if user:
                     fwd_from = p.Puppet.get_displayname(user, format=False)
+                else:
+                    fwd_from = None
         if not fwd_from:
             fwd_from = "Unknown user"
         html = (f"Forwarded message from <b>{fwd_from}</b><br/>"
@@ -232,7 +234,7 @@ def telegram_event_to_matrix(evt, source):
 def telegram_to_matrix(text, entities):
     try:
         return _telegram_to_matrix(text, entities)
-    except:
+    except Exception:
         log.exception("Failed to convert Telegram format:\n"
                       "message=%s\n"
                       "entities=%s",
diff --git a/mautrix_telegram/portal.py b/mautrix_telegram/portal.py
index 8de57792..d3d8bb19 100644
--- a/mautrix_telegram/portal.py
+++ b/mautrix_telegram/portal.py
@@ -87,12 +87,14 @@ class Portal:
             self._main_intent = puppet.intent if direct else self.az.intent
         return self._main_intent
 
-    def invite_matrix(self, users=[]):
+    def invite_matrix(self, users):
         if isinstance(users, str):
             self.main_intent.invite(self.mxid, users)
-        else:
+        elif isinstance(users, list):
             for user in users:
                 self.main_intent.invite(self.mxid, user)
+        else:
+            raise ValueError("Invalid invite identifier given to invite_matrix()")
 
     def update_after_create(self, user, entity, direct, puppet=None):
         if not direct:
@@ -106,7 +108,7 @@ class Portal:
             puppet.update_info(user, entity)
             puppet.intent.join_room(self.mxid)
 
-    def create_matrix_room(self, user, entity=None, invites=[], update_if_exists=True):
+    def create_matrix_room(self, user, entity=None, invites=None, update_if_exists=True):
         if not entity:
             entity = user.client.get_entity(self.peer)
             self.log.debug("Fetched data: %s", entity)
@@ -115,7 +117,7 @@ class Portal:
         if self.mxid:
             if update_if_exists:
                 self.update_after_create(user, entity, direct)
-            self.invite_matrix(invites)
+            self.invite_matrix(invites or [])
             return self.mxid
 
         self.log.debug(f"Creating room for {self.tgid_log}")
@@ -141,8 +143,8 @@ class Portal:
         if alias:
             # TODO properly handle existing room aliases
             intent.remove_room_alias(alias)
-        room = intent.create_room(alias=alias, is_public=public, invitees=invites, name=self.title,
-                                  is_direct=direct)
+        room = intent.create_room(alias=alias, is_public=public, invitees=invites or [],
+                                  name=self.title, is_direct=direct)
         if not room:
             raise Exception(f"Failed to create room for {self.tgid_log}")
 
@@ -166,7 +168,7 @@ class Portal:
         return config.get("bridge.alias_template", "telegram_{groupname}").format(
             groupname=username)
 
-    def sync_telegram_users(self, source, users=[]):
+    def sync_telegram_users(self, source, users):
         for entity in users:
             puppet = p.Puppet.get(entity.id)
             puppet.update_info(source, entity)
@@ -243,8 +245,8 @@ class Portal:
 
     @staticmethod
     def _get_largest_photo_size(photo):
-        return max(photo.sizes, key=(lambda photo: (
-            len(photo.bytes) if isinstance(photo, PhotoCachedSize) else photo.size)))
+        return max(photo.sizes, key=(lambda photo2: (
+            len(photo2.bytes) if isinstance(photo2, PhotoCachedSize) else photo2.size)))
 
     def update_avatar(self, user, photo):
         photo_id = f"{photo.volume_id}-{photo.local_id}"
@@ -293,8 +295,8 @@ class Portal:
     # endregion
     # region Matrix event handling
 
-    def _get_file_meta(self, body, mime):
-        file_name = None
+    @staticmethod
+    def _get_file_meta(body, mime):
         try:
             current_extension = body[body.rindex("."):]
             if mimetypes.types_map[current_extension] == mime:
@@ -510,14 +512,14 @@ class Portal:
         sender.intent.set_typing(self.mxid, is_typing=False)
         return sender.intent.send_image(self.mxid, uploaded["content_uri"], info=info, text=name)
 
-    @staticmethod
-    def convert_webp(file, to="png"):
+    def convert_webp(self, file, to="png"):
         try:
             image = Image.open(BytesIO(file)).convert("RGBA")
             new_file = BytesIO()
             image.save(new_file, to)
             return f"image/{to}", new_file.getvalue()
-        except:
+        except Exception:
+            self.log.exception(f"Failed to convert webp to {to}")
             return "image/webp", file
 
     def handle_telegram_document(self, source, sender, media):
@@ -551,7 +553,7 @@ class Portal:
             type = "m.image"
         sender.intent.set_typing(self.mxid, is_typing=False)
         return sender.intent.send_file(self.mxid, uploaded["content_uri"], info=info, text=name,
-                                       type=type)
+                                       file_type=type)
 
     def handle_telegram_location(self, source, sender, location):
         long = location.long
@@ -566,7 +568,8 @@ class Portal:
         url = f"https://maps.google.com/?q={lat},{long}"
 
         formatted_body = f"Location: <a href='{url}'>{body}</a>"
-        # At least Riot ignores formatting in m.location messages, so we'll add a plaintext link.
+        # At least riot-web ignores formatting in m.location messages,
+        # so we'll add a plaintext link.
         body = f"Location: {body}\n{url}"
 
         return sender.intent.send_message(self.mxid, {
diff --git a/mautrix_telegram/puppet.py b/mautrix_telegram/puppet.py
index 9dab2891..734ea435 100644
--- a/mautrix_telegram/puppet.py
+++ b/mautrix_telegram/puppet.py
@@ -75,6 +75,7 @@ class Puppet:
         }
         preferences = config.get("bridge.displayname_preference",
                                  ["full name", "username", "phone"])
+        name = None
         for preference in preferences:
             name = data[preference]
             if name:
diff --git a/mautrix_telegram/user.py b/mautrix_telegram/user.py
index efd87c81..0bfc0801 100644
--- a/mautrix_telegram/user.py
+++ b/mautrix_telegram/user.py
@@ -62,7 +62,7 @@ class User:
         return self.logged_in and self.whitelisted
 
     def get_input_entity(self, user):
-        return user.client.get_input_entity(InputUser(user_id=self.tgid))
+        return user.client.get_input_entity(InputUser(user_id=self.tgid, access_hash=0))
 
     # region Database conversion
 
@@ -202,7 +202,7 @@ class User:
     def update_catch(self, update):
         try:
             self.update(update)
-        except:
+        except Exception:
             self.log.exception("Failed to handle Telegram update")
 
     def update(self, update):