Replace all remaining six usage with native Python 3 equivalents (#7704)

73 files changed, 111 insertions, 237 deletions

diff --git a/changelog.d/7704.misc b/changelog.d/7704.misc
new file mode 100644
index 0000000000..7838a613c8
--- /dev/null
+++ b/changelog.d/7704.misc
@@ -0,0 +1 @@
+Replace all remaining uses of `six` with native Python 3 equivalents. Contributed by @ilmari.
diff --git a/contrib/graph/graph3.py b/contrib/graph/graph3.py
index 7f9e5374a6..3154638520 100644
--- a/contrib/graph/graph3.py
+++ b/contrib/graph/graph3.py
@@ -24,8 +24,6 @@ import argparse
 from synapse.events import FrozenEvent
 from synapse.util.frozenutils import unfreeze
 
-from six import string_types
-
 
 def make_graph(file_name, room_id, file_prefix, limit):
     print("Reading lines")
@@ -62,7 +60,7 @@ def make_graph(file_name, room_id, file_prefix, limit):
         for key, value in unfreeze(event.get_dict()["content"]).items():
             if value is None:
                 value = "<null>"
-            elif isinstance(value, string_types):
+            elif isinstance(value, str):
                 pass
             else:
                 value = json.dumps(value)
diff --git a/scripts-dev/federation_client.py b/scripts-dev/federation_client.py
index 7c19e405d4..531010185d 100755
--- a/scripts-dev/federation_client.py
+++ b/scripts-dev/federation_client.py
@@ -21,8 +21,7 @@ import argparse
 import base64
 import json
 import sys
-
-from six.moves.urllib import parse as urlparse
+from urllib import parse as urlparse
 
 import nacl.signing
 import requests
diff --git a/scripts/synapse_port_db b/scripts/synapse_port_db
index 9a0fbc61d8..a0d81c77c2 100755
--- a/scripts/synapse_port_db
+++ b/scripts/synapse_port_db
@@ -23,8 +23,6 @@ import sys
 import time
 import traceback
 
-from six import string_types
-
 import yaml
 
 from twisted.internet import defer, reactor
@@ -635,7 +633,7 @@ class Porter(object):
                 return bool(col)
             if isinstance(col, bytes):
                 return bytearray(col)
-            elif isinstance(col, string_types) and "\0" in col:
+            elif isinstance(col, str) and "\0" in col:
                 logger.warning(
                     "DROPPING ROW: NUL value in table %s col %s: %r",
                     table,
diff --git a/setup.cfg b/setup.cfg
index 12a7849081..f2bca272e1 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -31,7 +31,7 @@ sections=FUTURE,STDLIB,COMPAT,THIRDPARTY,TWISTED,FIRSTPARTY,TESTS,LOCALFOLDER
 default_section=THIRDPARTY
 known_first_party = synapse
 known_tests=tests
-known_compat = mock,six
+known_compat = mock
 known_twisted=twisted,OpenSSL
 multi_line_output=3
 include_trailing_comma=true
diff --git a/synapse/_scripts/register_new_matrix_user.py b/synapse/_scripts/register_new_matrix_user.py
index d528450c78..55cce2db22 100644
--- a/synapse/_scripts/register_new_matrix_user.py
+++ b/synapse/_scripts/register_new_matrix_user.py
@@ -23,8 +23,6 @@ import hmac
 import logging
 import sys
 
-from six.moves import input
-
 import requests as _requests
 import yaml
 
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index a07a54580d..5305038c21 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -17,10 +17,9 @@
 """Contains exceptions and error codes."""
 
 import logging
+from http import HTTPStatus
 from typing import Dict, List
 
-from six.moves import http_client
-
 from canonicaljson import json
 
 from twisted.web import http
@@ -173,7 +172,7 @@ class ConsentNotGivenError(SynapseError):
             consent_url (str): The URL where the user can give their consent
         """
         super(ConsentNotGivenError, self).__init__(
-            code=http_client.FORBIDDEN, msg=msg, errcode=Codes.CONSENT_NOT_GIVEN
+            code=HTTPStatus.FORBIDDEN, msg=msg, errcode=Codes.CONSENT_NOT_GIVEN
         )
         self._consent_uri = consent_uri
 
@@ -193,7 +192,7 @@ class UserDeactivatedError(SynapseError):
             msg (str): The human-readable error message
         """
         super(UserDeactivatedError, self).__init__(
-            code=http_client.FORBIDDEN, msg=msg, errcode=Codes.USER_DEACTIVATED
+            code=HTTPStatus.FORBIDDEN, msg=msg, errcode=Codes.USER_DEACTIVATED
         )
 
 
diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index 8b64d0a285..f988f62a1e 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -17,8 +17,6 @@
 # limitations under the License.
 from typing import List
 
-from six import text_type
-
 import jsonschema
 from canonicaljson import json
 from jsonschema import FormatChecker
@@ -313,7 +311,7 @@ class Filter(object):
 
             content = event.get("content", {})
             # check if there is a string url field in the content for filtering purposes
-            contains_url = isinstance(content.get("url"), text_type)
+            contains_url = isinstance(content.get("url"), str)
             labels = content.get(EventContentFields.LABELS, [])
 
         return self.check_fields(room_id, sender, ev_type, labels, contains_url)
diff --git a/synapse/api/urls.py b/synapse/api/urls.py
index f34434bd67..bd03ebca5a 100644
--- a/synapse/api/urls.py
+++ b/synapse/api/urls.py
@@ -17,8 +17,7 @@
 """Contains the URL paths to prefix various aspects of the server with. """
 import hmac
 from hashlib import sha256
-
-from six.moves.urllib.parse import urlencode
+from urllib.parse import urlencode
 
 from synapse.config import ConfigError
 
diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index 1b13e84425..0323256472 100644
--- a/synapse/appservice/__init__.py
+++ b/synapse/appservice/__init__.py
@@ -15,8 +15,6 @@
 import logging
 import re
 
-from six import string_types
-
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes
@@ -156,7 +154,7 @@ class ApplicationService(object):
                         )
 
                 regex = regex_obj.get("regex")
-                if isinstance(regex, string_types):
+                if isinstance(regex, str):
                     regex_obj["regex"] = re.compile(regex)  # Pre-compile regex
                 else:
                     raise ValueError("Expected string for 'regex' in ns '%s'" % ns)
diff --git a/synapse/appservice/api.py b/synapse/appservice/api.py
index 57174da021..da9a5e86d4 100644
--- a/synapse/appservice/api.py
+++ b/synapse/appservice/api.py
@@ -13,8 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-
-from six.moves import urllib
+import urllib
 
 from prometheus_client import Counter
 
diff --git a/synapse/config/_base.py b/synapse/config/_base.py
index 30d1050a91..1391e5fc43 100644
--- a/synapse/config/_base.py
+++ b/synapse/config/_base.py
@@ -22,8 +22,6 @@ from collections import OrderedDict
 from textwrap import dedent
 from typing import Any, MutableMapping, Optional
 
-from six import integer_types
-
 import yaml
 
 
@@ -117,7 +115,7 @@ class Config(object):
 
     @staticmethod
     def parse_size(value):
-        if isinstance(value, integer_types):
+        if isinstance(value, int):
             return value
         sizes = {"K": 1024, "M": 1024 * 1024}
         size = 1
@@ -129,7 +127,7 @@ class Config(object):
 
     @staticmethod
     def parse_duration(value):
-        if isinstance(value, integer_types):
+        if isinstance(value, int):
             return value
         second = 1000
         minute = 60 * second
diff --git a/synapse/config/appservice.py b/synapse/config/appservice.py
index ca43e96bd1..8ed3e24258 100644
--- a/synapse/config/appservice.py
+++ b/synapse/config/appservice.py
@@ -14,9 +14,7 @@
 
 import logging
 from typing import Dict
-
-from six import string_types
-from six.moves.urllib import parse as urlparse
+from urllib import parse as urlparse
 
 import yaml
 from netaddr import IPSet
@@ -98,17 +96,14 @@ def load_appservices(hostname, config_files):
 def _load_appservice(hostname, as_info, config_filename):
     required_string_fields = ["id", "as_token", "hs_token", "sender_localpart"]
     for field in required_string_fields:
-        if not isinstance(as_info.get(field), string_types):
+        if not isinstance(as_info.get(field), str):
             raise KeyError(
                 "Required string field: '%s' (%s)" % (field, config_filename)
             )
 
     # 'url' must either be a string or explicitly null, not missing
     # to avoid accidentally turning off push for ASes.
-    if (
-        not isinstance(as_info.get("url"), string_types)
-        and as_info.get("url", "") is not None
-    ):
+    if not isinstance(as_info.get("url"), str) and as_info.get("url", "") is not None:
         raise KeyError(
             "Required string field or explicit null: 'url' (%s)" % (config_filename,)
         )
@@ -138,7 +133,7 @@ def _load_appservice(hostname, as_info, config_filename):
                         ns,
                         regex_obj,
                     )
-                if not isinstance(regex_obj.get("regex"), string_types):
+                if not isinstance(regex_obj.get("regex"), str):
                     raise ValueError("Missing/bad type 'regex' key in %s", regex_obj)
                 if not isinstance(regex_obj.get("exclusive"), bool):
                     raise ValueError(
diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index a65538562b..e368ea564d 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -20,8 +20,6 @@ from datetime import datetime
 from hashlib import sha256
 from typing import List
 
-import six
-
 from unpaddedbase64 import encode_base64
 
 from OpenSSL import SSL, crypto
@@ -59,7 +57,7 @@ class TlsConfig(Config):
             logger.warning(ACME_SUPPORT_ENABLED_WARN)
 
         # hyperlink complains on py2 if this is not a Unicode
-        self.acme_url = six.text_type(
+        self.acme_url = str(
             acme_config.get("url", "https://acme-v01.api.letsencrypt.org/directory")
         )
         self.acme_port = acme_config.get("port", 80)
diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py
index a9f4025bfe..dbfc3e8972 100644
--- a/synapse/crypto/keyring.py
+++ b/synapse/crypto/keyring.py
@@ -15,11 +15,9 @@
 # limitations under the License.
 
 import logging
+import urllib
 from collections import defaultdict
 
-import six
-from six.moves import urllib
-
 import attr
 from signedjson.key import (
     decode_verify_key_bytes,
@@ -661,7 +659,7 @@ class PerspectivesKeyFetcher(BaseV2KeyFetcher):
         for response in query_response["server_keys"]:
             # do this first, so that we can give useful errors thereafter
             server_name = response.get("server_name")
-            if not isinstance(server_name, six.string_types):
+            if not isinstance(server_name, str):
                 raise KeyLookupError(
                     "Malformed response from key notary server %s: invalid server_name"
                     % (perspective_name,)
diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index dd340be9a7..f6b507977f 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -16,8 +16,6 @@ import collections
 import re
 from typing import Any, Mapping, Union
 
-from six import string_types
-
 from frozendict import frozendict
 
 from twisted.internet import defer
@@ -318,7 +316,7 @@ def serialize_event(
 
     if only_event_fields:
         if not isinstance(only_event_fields, list) or not all(
-            isinstance(f, string_types) for f in only_event_fields
+            isinstance(f, str) for f in only_event_fields
         ):
             raise TypeError("only_event_fields must be a list of strings")
         d = only_fields(d, only_event_fields)
diff --git a/synapse/events/validator.py b/synapse/events/validator.py
index b001c64bb4..588d222f36 100644
--- a/synapse/events/validator.py
+++ b/synapse/events/validator.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from six import integer_types, string_types
-
 from synapse.api.constants import MAX_ALIAS_LENGTH, EventTypes, Membership
 from synapse.api.errors import Codes, SynapseError
 from synapse.api.room_versions import EventFormatVersions
@@ -53,7 +51,7 @@ class EventValidator(object):
         event_strings = ["origin"]
 
         for s in event_strings:
-            if not isinstance(getattr(event, s), string_types):
+            if not isinstance(getattr(event, s), str):
                 raise SynapseError(400, "'%s' not a string type" % (s,))
 
         # Depending on the room version, ensure the data is spec compliant JSON.
@@ -90,7 +88,7 @@ class EventValidator(object):
         max_lifetime = event.content.get("max_lifetime")
 
         if min_lifetime is not None:
-            if not isinstance(min_lifetime, integer_types):
+            if not isinstance(min_lifetime, int):
                 raise SynapseError(
                     code=400,
                     msg="'min_lifetime' must be an integer",
@@ -124,7 +122,7 @@ class EventValidator(object):
                 )
 
         if max_lifetime is not None:
-            if not isinstance(max_lifetime, integer_types):
+            if not isinstance(max_lifetime, int):
                 raise SynapseError(
                     code=400,
                     msg="'max_lifetime' must be an integer",
@@ -183,7 +181,7 @@ class EventValidator(object):
             strings.append("state_key")
 
         for s in strings:
-            if not isinstance(getattr(event, s), string_types):
+            if not isinstance(getattr(event, s), str):
                 raise SynapseError(400, "Not '%s' a string type" % (s,))
 
         RoomID.from_string(event.room_id)
@@ -223,7 +221,7 @@ class EventValidator(object):
         for s in keys:
             if s not in d:
                 raise SynapseError(400, "'%s' not in content" % (s,))
-            if not isinstance(d[s], string_types):
+            if not isinstance(d[s], str):
                 raise SynapseError(400, "'%s' not a string type" % (s,))
 
     def _ensure_state_event(self, event):
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index b2ab5bd6a4..420df2385f 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -17,8 +17,6 @@ import logging
 from collections import namedtuple
 from typing import Iterable, List
 
-import six
-
 from twisted.internet import defer
 from twisted.internet.defer import Deferred, DeferredList
 from twisted.python.failure import Failure
@@ -294,7 +292,7 @@ def event_from_pdu_json(
     assert_params_in_dict(pdu_json, ("type", "depth"))
 
     depth = pdu_json["depth"]
-    if not isinstance(depth, six.integer_types):
+    if not isinstance(depth, int):
         raise SynapseError(400, "Depth %r not an intger" % (depth,), Codes.BAD_JSON)
 
     if depth < 0:
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 6920c23723..afe0a8238b 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -17,8 +17,6 @@
 import logging
 from typing import Any, Callable, Dict, List, Match, Optional, Tuple, Union
 
-import six
-
 from canonicaljson import json
 from prometheus_client import Counter
 
@@ -751,7 +749,7 @@ def server_matches_acl_event(server_name: str, acl_event: EventBase) -> bool:
 
 
 def _acl_entry_matches(server_name: str, acl_entry: str) -> Match:
-    if not isinstance(acl_entry, six.string_types):
+    if not isinstance(acl_entry, str):
         logger.warning(
             "Ignoring non-str ACL entry '%s' (is %s)", acl_entry, type(acl_entry)
         )
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index 060bf07197..9f99311419 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -15,10 +15,9 @@
 # limitations under the License.
 
 import logging
+import urllib
 from typing import Any, Dict, Optional
 
-from six.moves import urllib
-
 from twisted.internet import defer
 
 from synapse.api.constants import Membership
diff --git a/synapse/groups/groups_server.py b/synapse/groups/groups_server.py
index 8a9de913b3..8db8ab1b7b 100644
--- a/synapse/groups/groups_server.py
+++ b/synapse/groups/groups_server.py
@@ -17,8 +17,6 @@
 
 import logging
 
-from six import string_types
-
 from synapse.api.errors import Codes, SynapseError
 from synapse.types import GroupID, RoomID, UserID, get_domain_from_id
 from synapse.util.async_helpers import concurrently_execute
@@ -513,7 +511,7 @@ class GroupsServerHandler(GroupsServerWorkerHandler):
         for keyname in ("name", "avatar_url", "short_description", "long_description"):
             if keyname in content:
                 value = content[keyname]
-                if not isinstance(value, string_types):
+                if not isinstance(value, str):
                     raise SynapseError(400, "%r value is not a string" % (keyname,))
                 profile[keyname] = value
 
diff --git a/synapse/handlers/cas_handler.py b/synapse/handlers/cas_handler.py
index 64aaa1335c..76f213723a 100644
--- a/synapse/handlers/cas_handler.py
+++ b/synapse/handlers/cas_handler.py
@@ -14,11 +14,10 @@
 # limitations under the License.
 
 import logging
+import urllib
 import xml.etree.ElementTree as ET
 from typing import Dict, Optional, Tuple
 
-from six.moves import urllib
-
 from twisted.web.client import PartialDownloadError
 
 from synapse.api.errors import Codes, LoginError
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index d6038d9995..873f6bc39f 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -19,10 +19,9 @@
 
 import itertools
 import logging
+from http import HTTPStatus
 from typing import Dict, Iterable, List, Optional, Sequence, Tuple
 
-from six.moves import http_client, zip
-
 import attr
 from signedjson.key import decode_verify_key_bytes
 from signedjson.sign import verify_signed_json
@@ -1194,7 +1193,7 @@ class FederationHandler(BaseHandler):
                 ev.event_id,
                 len(ev.prev_event_ids()),
             )
-            raise SynapseError(http_client.BAD_REQUEST, "Too many prev_events")
+            raise SynapseError(HTTPStatus.BAD_REQUEST, "Too many prev_events")
 
         if len(ev.auth_event_ids()) > 10:
             logger.warning(
@@ -1202,7 +1201,7 @@ class FederationHandler(BaseHandler):
                 ev.event_id,
                 len(ev.auth_event_ids()),
             )
-            raise SynapseError(http_client.BAD_REQUEST, "Too many auth_events")
+            raise SynapseError(HTTPStatus.BAD_REQUEST, "Too many auth_events")
 
     async def send_invite(self, target_host, event):
         """ Sends the invite to the remote server for signing.
@@ -1545,7 +1544,7 @@ class FederationHandler(BaseHandler):
 
         # block any attempts to invite the server notices mxid
         if event.state_key == self._server_notices_mxid:
-            raise SynapseError(http_client.FORBIDDEN, "Cannot invite this user")
+            raise SynapseError(HTTPStatus.FORBIDDEN, "Cannot invite this user")
 
         # keep a record of the room version, if we don't yet know it.
         # (this may get overwritten if we later get a different room version in a
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 354da9a3b5..200127d291 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -17,8 +17,6 @@
 import logging
 from typing import Optional, Tuple
 
-from six import string_types
-
 from canonicaljson import encode_canonical_json, json
 
 from twisted.internet import defer
@@ -715,7 +713,7 @@ class EventCreationHandler(object):
 
             spam_error = self.spam_checker.check_event_for_spam(event)
             if spam_error:
-                if not isinstance(spam_error, string_types):
+                if not isinstance(spam_error, str):
                     spam_error = "Spam is not permitted here"
                 raise SynapseError(403, spam_error, Codes.FORBIDDEN)
 
diff --git a/synapse/handlers/profile.py b/synapse/handlers/profile.py
index 302efc1b9a..4b1e3073a8 100644
--- a/synapse/handlers/profile.py
+++ b/synapse/handlers/profile.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from six import raise_from
-
 from twisted.internet import defer
 
 from synapse.api.errors import (
@@ -84,7 +82,7 @@ class BaseProfileHandler(BaseHandler):
                 )
                 return result
             except RequestSendFailed as e:
-                raise_from(SynapseError(502, "Failed to fetch profile"), e)
+                raise SynapseError(502, "Failed to fetch profile") from e
             except HttpResponseException as e:
                 raise e.to_synapse_error()
 
@@ -135,7 +133,7 @@ class BaseProfileHandler(BaseHandler):
                     ignore_backoff=True,
                 )
             except RequestSendFailed as e:
-                raise_from(SynapseError(502, "Failed to fetch profile"), e)
+                raise SynapseError(502, "Failed to fetch profile") from e
             except HttpResponseException as e:
                 raise e.to_synapse_error()
 
@@ -212,7 +210,7 @@ class BaseProfileHandler(BaseHandler):
                     ignore_backoff=True,
                 )
             except RequestSendFailed as e:
-                raise_from(SynapseError(502, "Failed to fetch profile"), e)
+                raise SynapseError(502, "Failed to fetch profile") from e
             except HttpResponseException as e:
                 raise e.to_synapse_error()
 
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index f7401373ca..950a84acd0 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -24,8 +24,6 @@ import string
 from collections import OrderedDict
 from typing import Tuple
 
-from six import string_types
-
 from synapse.api.constants import (
     EventTypes,
     JoinRules,
@@ -595,7 +593,7 @@ class RoomCreationHandler(BaseHandler):
             "room_version", self.config.default_room_version.identifier
         )
 
-        if not isinstance(room_version_id, string_types):
+        if not isinstance(room_version_id, str):
             raise SynapseError(400, "room_version must be a string", Codes.BAD_JSON)
 
         room_version = KNOWN_ROOM_VERSIONS.get(room_version_id)
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 0f7af982f0..27c479da9e 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -17,10 +17,9 @@
 
 import abc
 import logging
+from http import HTTPStatus
 from typing import Dict, Iterable, List, Optional, Tuple
 
-from six.moves import http_client
-
 from synapse import types
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import AuthError, Codes, SynapseError
@@ -361,7 +360,7 @@ class RoomMemberHandler(object):
         if effective_membership_state == Membership.INVITE:
             # block any attempts to invite the server notices mxid
             if target.to_string() == self._server_notices_mxid:
-                raise SynapseError(http_client.FORBIDDEN, "Cannot invite this user")
+                raise SynapseError(HTTPStatus.FORBIDDEN, "Cannot invite this user")
 
             block_invite = False
 
@@ -444,7 +443,7 @@ class RoomMemberHandler(object):
                 is_blocked = await self._is_server_notice_room(room_id)
                 if is_blocked:
                     raise SynapseError(
-                        http_client.FORBIDDEN,
+                        HTTPStatus.FORBIDDEN,
                         "You cannot reject this invite",
                         errcode=Codes.CANNOT_LEAVE_SERVER_NOTICE_ROOM,
                     )
diff --git a/synapse/http/client.py b/synapse/http/client.py
index 3cef747a4d..8743e9839d 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -15,11 +15,9 @@
 # limitations under the License.
 
 import logging
+import urllib
 from io import BytesIO
 
-from six import raise_from, text_type
-from six.moves import urllib
-
 import treq
 from canonicaljson import encode_canonical_json, json
 from netaddr import IPAddress
@@ -577,7 +575,7 @@ class SimpleHttpClient(object):
             # This can happen e.g. because the body is too large.
             raise
         except Exception as e:
-            raise_from(SynapseError(502, ("Failed to download remote body: %s" % e)), e)
+            raise SynapseError(502, ("Failed to download remote body: %s" % e)) from e
 
         return (
             length,
@@ -638,7 +636,7 @@ def encode_urlencode_args(args):
 
 
 def encode_urlencode_arg(arg):
-    if isinstance(arg, text_type):
+    if isinstance(arg, str):
         return arg.encode("utf-8")
     elif isinstance(arg, list):
         return [encode_urlencode_arg(i) for i in arg]
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 2d47b9ea00..7b33b9f10a 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -17,11 +17,9 @@ import cgi
 import logging
 import random
 import sys
+import urllib
 from io import BytesIO
 
-from six import raise_from, string_types
-from six.moves import urllib
-
 import attr
 import treq
 from canonicaljson import encode_canonical_json
@@ -432,10 +430,10 @@ class MatrixFederationHttpClient(object):
                     except TimeoutError as e:
                         raise RequestSendFailed(e, can_retry=True) from e
                     except DNSLookupError as e:
-                        raise_from(RequestSendFailed(e, can_retry=retry_on_dns_fail), e)
+                        raise RequestSendFailed(e, can_retry=retry_on_dns_fail) from e
                     except Exception as e:
                         logger.info("Failed to send request: %s", e)
-                        raise_from(RequestSendFailed(e, can_retry=True), e)
+                        raise RequestSendFailed(e, can_retry=True) from e
 
                     incoming_responses_counter.labels(
                         request.method, response.code
@@ -487,7 +485,7 @@ class MatrixFederationHttpClient(object):
                         # Retry if the error is a 429 (Too Many Requests),
                         # otherwise just raise a standard HttpResponseException
                         if response.code == 429:
-                            raise_from(RequestSendFailed(e, can_retry=True), e)
+                            raise RequestSendFailed(e, can_retry=True) from e
                         else:
                             raise e
 
@@ -998,7 +996,7 @@ def encode_query_args(args):
 
     encoded_args = {}
     for k, vs in args.items():
-        if isinstance(vs, string_types):
+        if isinstance(vs, str):
             vs = [vs]
         encoded_args[k] = [v.encode("UTF-8") for v in vs]
 
diff --git a/synapse/http/server.py b/synapse/http/server.py
index 2487a72171..6aa1dc1f92 100644
--- a/synapse/http/server.py
+++ b/synapse/http/server.py
@@ -16,10 +16,10 @@
 
 import collections
 import html
-import http.client
 import logging
 import types
 import urllib
+from http import HTTPStatus
 from io import BytesIO
 from typing import Awaitable, Callable, TypeVar, Union
 
@@ -188,7 +188,7 @@ def return_html_error(
                 exc_info=(f.type, f.value, f.getTracebackObject()),
             )
     else:
-        code = http.HTTPStatus.INTERNAL_SERVER_ERROR
+        code = HTTPStatus.INTERNAL_SERVER_ERROR
         msg = "Internal server error"
 
         logger.error(
diff --git a/synapse/logging/formatter.py b/synapse/logging/formatter.py
index fbf570c756..d736ad5b9b 100644
--- a/synapse/logging/formatter.py
+++ b/synapse/logging/formatter.py
@@ -16,8 +16,7 @@
 
 import logging
 import traceback
-
-from six import StringIO
+from io import StringIO
 
 
 class LogFormatter(logging.Formatter):
diff --git a/synapse/push/mailer.py b/synapse/push/mailer.py
index d57a66a697..dda560b2c2 100644
--- a/synapse/push/mailer.py
+++ b/synapse/push/mailer.py
@@ -17,12 +17,11 @@ import email.mime.multipart
 import email.utils
 import logging
 import time
+import urllib
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 from typing import Iterable, List, TypeVar
 
-from six.moves import urllib
-
 import bleach
 import jinja2
 
diff --git a/synapse/push/push_rule_evaluator.py b/synapse/push/push_rule_evaluator.py
index aeac257a6e..8e0d3a416d 100644
--- a/synapse/push/push_rule_evaluator.py
+++ b/synapse/push/push_rule_evaluator.py
@@ -18,8 +18,6 @@ import logging
 import re
 from typing import Pattern
 
-from six import string_types
-
 from synapse.events import EventBase
 from synapse.types import UserID
 from synapse.util.caches import register_cache
@@ -244,7 +242,7 @@ def _flatten_dict(d, prefix=[], result=None):
     if result is None:
         result = {}
     for key, value in d.items():
-        if isinstance(value, string_types):
+        if isinstance(value, str):
             result[".".join(prefix + [key])] = value.lower()
         elif hasattr(value, "items"):
             _flatten_dict(value, prefix=(prefix + [key]), result=result)
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index 8ec1a619a2..d655aba35c 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -66,7 +66,6 @@ REQUIREMENTS = [
     "pymacaroons>=0.13.0",
     "msgpack>=0.5.2",
     "phonenumbers>=8.2.0",
-    "six>=1.10",
     "prometheus_client>=0.0.18,<0.8.0",
     # we use attr.validators.deep_iterable, which arrived in 19.1.0
     "attrs>=19.1.0",
diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py
index 793cef6c26..9caf1e80c1 100644
--- a/synapse/replication/http/_base.py
+++ b/synapse/replication/http/_base.py
@@ -16,12 +16,10 @@
 import abc
 import logging
 import re
+import urllib
 from inspect import signature
 from typing import Dict, List, Tuple
 
-from six import raise_from
-from six.moves import urllib
-
 from twisted.internet import defer
 
 from synapse.api.errors import (
@@ -220,7 +218,7 @@ class ReplicationEndpoint(object):
                 # importantly, not stack traces everywhere)
                 raise e.to_synapse_error()
             except RequestSendFailed as e:
-                raise_from(SynapseError(502, "Failed to talk to master"), e)
+                raise SynapseError(502, "Failed to talk to master") from e
 
             return result
 
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index fefc8f71fa..e4330c39d6 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -16,9 +16,7 @@ import hashlib
 import hmac
 import logging
 import re
-
-from six import text_type
-from six.moves import http_client
+from http import HTTPStatus
 
 from synapse.api.constants import UserTypes
 from synapse.api.errors import Codes, NotFoundError, SynapseError
@@ -215,10 +213,7 @@ class UserRestServletV2(RestServlet):
                     await self.store.set_server_admin(target_user, set_admin_to)
 
             if "password" in body:
-                if (
-                    not isinstance(body["password"], text_type)
-                    or len(body["password"]) > 512
-                ):
+                if not isinstance(body["password"], str) or len(body["password"]) > 512:
                     raise SynapseError(400, "Invalid password")
                 else:
                     new_password = body["password"]
@@ -252,7 +247,7 @@ class UserRestServletV2(RestServlet):
             password = body.get("password")
             password_hash = None
             if password is not None:
-                if not isinstance(password, text_type) or len(password) > 512:
+                if not isinstance(password, str) or len(password) > 512:
                     raise SynapseError(400, "Invalid password")
                 password_hash = await self.auth_handler.hash(password)
 
@@ -370,10 +365,7 @@ class UserRegisterServlet(RestServlet):
                 400, "username must be specified", errcode=Codes.BAD_JSON
             )
         else:
-            if (
-                not isinstance(body["username"], text_type)
-                or len(body["username"]) > 512
-            ):
+            if not isinstance(body["username"], str) or len(body["username"]) > 512:
                 raise SynapseError(400, "Invalid username")
 
             username = body["username"].encode("utf-8")
@@ -386,7 +378,7 @@ class UserRegisterServlet(RestServlet):
             )
         else:
             password = body["password"]
-            if not isinstance(password, text_type) or len(password) > 512:
+            if not isinstance(password, str) or len(password) > 512:
                 raise SynapseError(400, "Invalid password")
 
             password_bytes = password.encode("utf-8")
@@ -477,7 +469,7 @@ class DeactivateAccountRestServlet(RestServlet):
         erase = body.get("erase", False)
         if not isinstance(erase, bool):
             raise SynapseError(
-                http_client.BAD_REQUEST,
+                HTTPStatus.BAD_REQUEST,
                 "Param 'erase' must be a boolean, if given",
                 Codes.BAD_JSON,
             )
diff --git a/synapse/rest/client/v1/presence.py b/synapse/rest/client/v1/presence.py
index 7cf007d35e..970fdd5834 100644
--- a/synapse/rest/client/v1/presence.py
+++ b/synapse/rest/client/v1/presence.py
@@ -17,8 +17,6 @@
 """
 import logging
 
-from six import string_types
-
 from synapse.api.errors import AuthError, SynapseError
 from synapse.handlers.presence import format_user_presence_state
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
@@ -73,7 +71,7 @@ class PresenceStatusRestServlet(RestServlet):
 
             if "status_msg" in content:
                 state["status_msg"] = content.pop("status_msg")
-                if not isinstance(state["status_msg"], string_types):
+                if not isinstance(state["status_msg"], str):
                     raise SynapseError(400, "status_msg must be a string.")
 
             if content:
diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index 105e0cf4d2..46811abbfa 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -18,8 +18,7 @@
 import logging
 import re
 from typing import List, Optional
-
-from six.moves.urllib import parse as urlparse
+from urllib import parse as urlparse
 
 from canonicaljson import json
 
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 1dc4a3247f..923bcb9f85 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -15,8 +15,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-
-from six.moves import http_client
+from http import HTTPStatus
 
 from synapse.api.constants import LoginType
 from synapse.api.errors import Codes, SynapseError, ThreepidValidationError
@@ -321,7 +320,7 @@ class DeactivateAccountRestServlet(RestServlet):
         erase = body.get("erase", False)
         if not isinstance(erase, bool):
             raise SynapseError(
-                http_client.BAD_REQUEST,
+                HTTPStatus.BAD_REQUEST,
                 "Param 'erase' must be a boolean, if given",
                 Codes.BAD_JSON,
             )
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index b9ffe86b2a..141a3f5fac 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -18,8 +18,6 @@ import hmac
 import logging
 from typing import List, Union
 
-from six import string_types
-
 import synapse
 import synapse.api.auth
 import synapse.types
@@ -413,7 +411,7 @@ class RegisterRestServlet(RestServlet):
         # in sessions. Pull out the username/password provided to us.
         if "password" in body:
             password = body.pop("password")
-            if not isinstance(password, string_types) or len(password) > 512:
+            if not isinstance(password, str) or len(password) > 512:
                 raise SynapseError(400, "Invalid password")
             self.password_policy_handler.validate_password(password)
 
@@ -425,10 +423,7 @@ class RegisterRestServlet(RestServlet):
 
         desired_username = None
         if "username" in body:
-            if (
-                not isinstance(body["username"], string_types)
-                or len(body["username"]) > 512
-            ):
+            if not isinstance(body["username"], str) or len(body["username"]) > 512:
                 raise SynapseError(400, "Invalid username")
             desired_username = body["username"]
 
@@ -453,7 +448,7 @@ class RegisterRestServlet(RestServlet):
 
             access_token = self.auth.get_access_token_from_request(request)
 
-            if isinstance(desired_username, string_types):
+            if isinstance(desired_username, str):
                 result = await self._do_appservice_registration(
                     desired_username, access_token, body
                 )
diff --git a/synapse/rest/client/v2_alpha/report_event.py b/synapse/rest/client/v2_alpha/report_event.py
index f067b5edac..e15927c4ea 100644
--- a/synapse/rest/client/v2_alpha/report_event.py
+++ b/synapse/rest/client/v2_alpha/report_event.py
@@ -14,9 +14,7 @@
 # limitations under the License.
 
 import logging
-
-from six import string_types
-from six.moves import http_client
+from http import HTTPStatus
 
 from synapse.api.errors import Codes, SynapseError
 from synapse.http.servlet import (
@@ -47,15 +45,15 @@ class ReportEventRestServlet(RestServlet):
         body = parse_json_object_from_request(request)
         assert_params_in_dict(body, ("reason", "score"))
 
-        if not isinstance(body["reason"], string_types):
+        if not isinstance(body["reason"], str):
             raise SynapseError(
-                http_client.BAD_REQUEST,
+                HTTPStatus.BAD_REQUEST,
                 "Param 'reason' must be a string",
                 Codes.BAD_JSON,
             )
         if not isinstance(body["score"], int):
             raise SynapseError(
-                http_client.BAD_REQUEST,
+                HTTPStatus.BAD_REQUEST,
                 "Param 'score' must be an integer",
                 Codes.BAD_JSON,
             )
diff --git a/synapse/rest/consent/consent_resource.py b/synapse/rest/consent/consent_resource.py
index 1ddf9997ff..049c16b236 100644
--- a/synapse/rest/consent/consent_resource.py
+++ b/synapse/rest/consent/consent_resource.py
@@ -16,10 +16,9 @@
 import hmac
 import logging
 from hashlib import sha256
+from http import HTTPStatus
 from os import path
 
-from six.moves import http_client
-
 import jinja2
 from jinja2 import TemplateNotFound
 
@@ -223,4 +222,4 @@ class ConsentResource(DirectServeResource):
         )
 
         if not compare_digest(want_mac, userhmac):
-            raise SynapseError(http_client.FORBIDDEN, "HMAC incorrect")
+            raise SynapseError(HTTPStatus.FORBIDDEN, "HMAC incorrect")
diff --git a/synapse/rest/media/v1/_base.py b/synapse/rest/media/v1/_base.py
index 3689777266..595849f9d5 100644
--- a/synapse/rest/media/v1/_base.py
+++ b/synapse/rest/media/v1/_base.py
@@ -16,8 +16,7 @@
 
 import logging
 import os
-
-from six.moves import urllib
+import urllib
 
 from twisted.internet import defer
 from twisted.protocols.basic import FileSender
diff --git a/synapse/rest/media/v1/media_storage.py b/synapse/rest/media/v1/media_storage.py
index 683a79c966..79cb0dddbe 100644
--- a/synapse/rest/media/v1/media_storage.py
+++ b/synapse/rest/media/v1/media_storage.py
@@ -17,9 +17,6 @@ import contextlib
 import logging
 import os
 import shutil
-import sys
-
-import six
 
 from twisted.internet import defer
 from twisted.protocols.basic import FileSender
@@ -117,12 +114,11 @@ class MediaStorage(object):
             with open(fname, "wb") as f:
                 yield f, fname, finish
         except Exception:
-            t, v, tb = sys.exc_info()
             try:
                 os.remove(fname)
             except Exception:
                 pass
-            six.reraise(t, v, tb)
+            raise
 
         if not finished_called:
             raise Exception("Finished callback not called")
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index f206605727..f67e0fb3ec 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -24,10 +24,7 @@ import shutil
 import sys
 import traceback
 from typing import Dict, Optional
-
-import six
-from six import string_types
-from six.moves import urllib_parse as urlparse
+from urllib import parse as urlparse
 
 from canonicaljson import json
 
@@ -188,7 +185,7 @@ class PreviewUrlResource(DirectServeResource):
             # It may be stored as text in the database, not as bytes (such as
             # PostgreSQL). If so, encode it back before handing it on.
             og = cache_result["og"]
-            if isinstance(og, six.text_type):
+            if isinstance(og, str):
                 og = og.encode("utf8")
             return og
 
@@ -631,7 +628,7 @@ def _iterate_over_text(tree, *tags_to_ignore):
         if el is None:
             return
 
-        if isinstance(el, string_types):
+        if isinstance(el, str):
             yield el
         elif el.tag not in tags_to_ignore:
             # el.text is the text before the first child, so we can immediately
diff --git a/synapse/server_notices/consent_server_notices.py b/synapse/server_notices/consent_server_notices.py
index e7e8b8e688..3bfc8d7278 100644
--- a/synapse/server_notices/consent_server_notices.py
+++ b/synapse/server_notices/consent_server_notices.py
@@ -14,8 +14,6 @@
 # limitations under the License.
 import logging
 
-from six import string_types
-
 from synapse.api.errors import SynapseError
 from synapse.api.urls import ConsentURIBuilder
 from synapse.config import ConfigError
@@ -118,7 +116,7 @@ def copy_with_str_subst(x, substitutions):
     Returns:
         copy of x
     """
-    if isinstance(x, string_types):
+    if isinstance(x, str):
         return x % substitutions
     if isinstance(x, dict):
         return {k: copy_with_str_subst(v, substitutions) for (k, v) in x.items()}
diff --git a/synapse/storage/data_stores/main/event_federation.py b/synapse/storage/data_stores/main/event_federation.py
index 24ce8c4330..a6bb3221ff 100644
--- a/synapse/storage/data_stores/main/event_federation.py
+++ b/synapse/storage/data_stores/main/event_federation.py
@@ -14,10 +14,9 @@
 # limitations under the License.
 import itertools
 import logging
+from queue import Empty, PriorityQueue
 from typing import Dict, List, Optional, Set, Tuple
 
-from six.moves.queue import Empty, PriorityQueue
-
 from twisted.internet import defer
 
 from synapse.api.errors import StoreError
diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py
index 8a13101f1d..cfd24d2f06 100644
--- a/synapse/storage/data_stores/main/events.py
+++ b/synapse/storage/data_stores/main/events.py
@@ -21,9 +21,6 @@ from collections import OrderedDict, namedtuple
 from functools import wraps
 from typing import TYPE_CHECKING, Dict, Iterable, List, Tuple
 
-from six import integer_types, text_type
-from six.moves import range
-
 import attr
 from canonicaljson import json
 from prometheus_client import Counter
@@ -893,8 +890,7 @@ class PersistEventsStore:
                     "received_ts": self._clock.time_msec(),
                     "sender": event.sender,
                     "contains_url": (
-                        "url" in event.content
-                        and isinstance(event.content["url"], text_type)
+                        "url" in event.content and isinstance(event.content["url"], str)
                     ),
                 }
                 for event, _ in events_and_contexts
@@ -1345,10 +1341,10 @@ class PersistEventsStore:
         ):
             if (
                 "min_lifetime" in event.content
-                and not isinstance(event.content.get("min_lifetime"), integer_types)
+                and not isinstance(event.content.get("min_lifetime"), int)
             ) or (
                 "max_lifetime" in event.content
-                and not isinstance(event.content.get("max_lifetime"), integer_types)
+                and not isinstance(event.content.get("max_lifetime"), int)
             ):
                 # Ignore the event if one of the value isn't an integer.
                 return
diff --git a/synapse/storage/data_stores/main/events_bg_updates.py b/synapse/storage/data_stores/main/events_bg_updates.py
index f54c8b1ee0..62d28f44dc 100644
--- a/synapse/storage/data_stores/main/events_bg_updates.py
+++ b/synapse/storage/data_stores/main/events_bg_updates.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from six import text_type
-
 from canonicaljson import json
 
 from twisted.internet import defer
@@ -133,7 +131,7 @@ class EventsBackgroundUpdatesStore(SQLBaseStore):
 
                     contains_url = "url" in content
                     if contains_url:
-                        contains_url &= isinstance(content["url"], text_type)
+                        contains_url &= isinstance(content["url"], str)
                 except (KeyError, AttributeError):
                     # If the event is missing a necessary field then
                     # skip over it.
diff --git a/synapse/storage/data_stores/main/schema/delta/30/as_users.py b/synapse/storage/data_stores/main/schema/delta/30/as_users.py
index 9b95411fb6..b42c02710a 100644
--- a/synapse/storage/data_stores/main/schema/delta/30/as_users.py
+++ b/synapse/storage/data_stores/main/schema/delta/30/as_users.py
@@ -13,8 +13,6 @@
 # limitations under the License.
 import logging
 
-from six.moves import range
-
 from synapse.config.appservice import load_appservices
 
 logger = logging.getLogger(__name__)
diff --git a/synapse/storage/data_stores/main/search.py b/synapse/storage/data_stores/main/search.py
index 13f49d8060..a8381dc577 100644
--- a/synapse/storage/data_stores/main/search.py
+++ b/synapse/storage/data_stores/main/search.py
@@ -17,8 +17,6 @@ import logging
 import re
 from collections import namedtuple
 
-from six import string_types
-
 from canonicaljson import json
 
 from twisted.internet import defer
@@ -180,7 +178,7 @@ class SearchBackgroundUpdateStore(SearchWorkerStore):
                     # skip over it.
                     continue
 
-                if not isinstance(value, string_types):
+                if not isinstance(value, str):
                     # If the event body, name or topic isn't a string
                     # then skip over it
                     continue
diff --git a/synapse/storage/data_stores/main/stream.py b/synapse/storage/data_stores/main/stream.py
index e89f0bffb5..379d758b5d 100644
--- a/synapse/storage/data_stores/main/stream.py
+++ b/synapse/storage/data_stores/main/stream.py
@@ -40,8 +40,6 @@ import abc
 import logging
 from collections import namedtuple
 
-from six.moves import range
-
 from twisted.internet import defer
 
 from synapse.logging.context import make_deferred_yieldable, run_in_background
diff --git a/synapse/storage/data_stores/main/tags.py b/synapse/storage/data_stores/main/tags.py
index 4219018302..f8c776be3f 100644
--- a/synapse/storage/data_stores/main/tags.py
+++ b/synapse/storage/data_stores/main/tags.py
@@ -16,8 +16,6 @@
 
 import logging
 
-from six.moves import range
-
 from canonicaljson import json
 
 from twisted.internet import defer
diff --git a/synapse/storage/data_stores/state/store.py b/synapse/storage/data_stores/state/store.py
index b720212e55..5db9f20135 100644
--- a/synapse/storage/data_stores/state/store.py
+++ b/synapse/storage/data_stores/state/store.py
@@ -17,8 +17,6 @@ import logging
 from collections import namedtuple
 from typing import Dict, Iterable, List, Set, Tuple
 
-from six.moves import range
-
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes
diff --git a/synapse/storage/database.py b/synapse/storage/database.py
index 645a70934c..3be20c866a 100644
--- a/synapse/storage/database.py
+++ b/synapse/storage/database.py
@@ -16,6 +16,7 @@
 # limitations under the License.
 import logging
 import time
+from sys import intern
 from time import monotonic as monotonic_time
 from typing import (
     Any,
@@ -29,8 +30,6 @@ from typing import (
     TypeVar,
 )
 
-from six.moves import intern, range
-
 from prometheus_client import Histogram
 
 from twisted.enterprise import adbapi
diff --git a/synapse/storage/persist_events.py b/synapse/storage/persist_events.py
index 92dfd709bc..ec894a91cb 100644
--- a/synapse/storage/persist_events.py
+++ b/synapse/storage/persist_events.py
@@ -20,8 +20,6 @@ import logging
 from collections import deque, namedtuple
 from typing import Iterable, List, Optional, Set, Tuple
 
-from six.moves import range
-
 from prometheus_client import Counter, Histogram
 
 from twisted.internet import defer
diff --git a/synapse/util/async_helpers.py b/synapse/util/async_helpers.py
index f7af2bca7f..df42486351 100644
--- a/synapse/util/async_helpers.py
+++ b/synapse/util/async_helpers.py
@@ -19,8 +19,6 @@ import logging
 from contextlib import contextmanager
 from typing import Dict, Sequence, Set, Union
 
-from six.moves import range
-
 import attr
 
 from twisted.internet import defer
diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py
index 2a161bf244..c541bf4579 100644
--- a/synapse/util/caches/stream_change_cache.py
+++ b/synapse/util/caches/stream_change_cache.py
@@ -17,8 +17,6 @@ import logging
 import math
 from typing import Dict, FrozenSet, List, Mapping, Optional, Set, Union
 
-from six import integer_types
-
 from sortedcontainers import SortedDict
 
 from synapse.types import Collection
@@ -88,7 +86,7 @@ class StreamChangeCache:
     def has_entity_changed(self, entity: EntityType, stream_pos: int) -> bool:
         """Returns True if the entity may have been updated since stream_pos
         """
-        assert type(stream_pos) in integer_types
+        assert isinstance(stream_pos, int)
 
         if stream_pos < self._earliest_known_stream_pos:
             self.metrics.inc_misses()
diff --git a/synapse/util/file_consumer.py b/synapse/util/file_consumer.py
index 8b17d1c8b8..6a3f6177b1 100644
--- a/synapse/util/file_consumer.py
+++ b/synapse/util/file_consumer.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from six.moves import queue
+import queue
 
 from twisted.internet import threads
 
diff --git a/synapse/util/frozenutils.py b/synapse/util/frozenutils.py
index 9815bb8667..eab78dd256 100644
--- a/synapse/util/frozenutils.py
+++ b/synapse/util/frozenutils.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from six import binary_type, text_type
-
 from canonicaljson import json
 from frozendict import frozendict
 
@@ -26,7 +24,7 @@ def freeze(o):
     if isinstance(o, frozendict):
         return o
 
-    if isinstance(o, (binary_type, text_type)):
+    if isinstance(o, (bytes, str)):
         return o
 
     try:
@@ -41,7 +39,7 @@ def unfreeze(o):
     if isinstance(o, (dict, frozendict)):
         return dict({k: unfreeze(v) for k, v in o.items()})
 
-    if isinstance(o, (binary_type, text_type)):
+    if isinstance(o, (bytes, str)):
         return o
 
     try:
diff --git a/synapse/util/wheel_timer.py b/synapse/util/wheel_timer.py
index 9bf6a44f75..023beb5ede 100644
--- a/synapse/util/wheel_timer.py
+++ b/synapse/util/wheel_timer.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from six.moves import range
-
 
 class _Entry(object):
     __slots__ = ["end_key", "queue"]
diff --git a/synapse/visibility.py b/synapse/visibility.py
index 780927cda1..3dfd4af26c 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -16,8 +16,6 @@
 import logging
 import operator
 
-from six.moves import map
-
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, Membership
diff --git a/synctl b/synctl
index 960fd357ee..ca398b84bd 100755
--- a/synctl
+++ b/synctl
@@ -26,8 +26,6 @@ import subprocess
 import sys
 import time
 
-from six import iteritems
-
 import yaml
 
 from synapse.config import find_config_files
@@ -251,7 +249,7 @@ def main():
         os.environ["SYNAPSE_CACHE_FACTOR"] = str(cache_factor)
 
     cache_factors = config.get("synctl_cache_factors", {})
-    for cache_name, factor in iteritems(cache_factors):
+    for cache_name, factor in cache_factors.items():
         os.environ["SYNAPSE_CACHE_FACTOR_" + cache_name.upper()] = str(factor)
 
     worker_configfiles = []
@@ -362,7 +360,7 @@ def main():
             if worker.cache_factor:
                 os.environ["SYNAPSE_CACHE_FACTOR"] = str(worker.cache_factor)
 
-            for cache_name, factor in iteritems(worker.cache_factors):
+            for cache_name, factor in worker.cache_factors.items():
                 os.environ["SYNAPSE_CACHE_FACTOR_" + cache_name.upper()] = str(factor)
 
             if not start_worker(worker.app, configfile, worker.configfile):
diff --git a/tests/rest/client/v1/test_rooms.py b/tests/rest/client/v1/test_rooms.py
index 4886bbb401..5ccda8b2bd 100644
--- a/tests/rest/client/v1/test_rooms.py
+++ b/tests/rest/client/v1/test_rooms.py
@@ -19,9 +19,9 @@
 """Tests REST events for /rooms paths."""
 
 import json
+from urllib import parse as urlparse
 
 from mock import Mock
-from six.moves.urllib import parse as urlparse
 
 from twisted.internet import defer
 
diff --git a/tests/rest/client/v2_alpha/test_relations.py b/tests/rest/client/v2_alpha/test_relations.py
index c7e5859970..fd641a7c2f 100644
--- a/tests/rest/client/v2_alpha/test_relations.py
+++ b/tests/rest/client/v2_alpha/test_relations.py
@@ -15,8 +15,7 @@
 
 import itertools
 import json
-
-import six
+import urllib
 
 from synapse.api.constants import EventTypes, RelationTypes
 from synapse.rest import admin
@@ -134,7 +133,7 @@ class RelationsTestCase(unittest.HomeserverTestCase):
         # Make sure next_batch has something in it that looks like it could be a
         # valid token.
         self.assertIsInstance(
-            channel.json_body.get("next_batch"), six.string_types, channel.json_body
+            channel.json_body.get("next_batch"), str, channel.json_body
         )
 
     def test_repeated_paginate_relations(self):
@@ -278,7 +277,7 @@ class RelationsTestCase(unittest.HomeserverTestCase):
 
         prev_token = None
         found_event_ids = []
-        encoded_key = six.moves.urllib.parse.quote_plus("👍".encode("utf-8"))
+        encoded_key = urllib.parse.quote_plus("👍".encode("utf-8"))
         for _ in range(20):
             from_token = ""
             if prev_token:
@@ -670,7 +669,7 @@ class RelationsTestCase(unittest.HomeserverTestCase):
 
         query = ""
         if key:
-            query = "?key=" + six.moves.urllib.parse.quote_plus(key.encode("utf-8"))
+            query = "?key=" + urllib.parse.quote_plus(key.encode("utf-8"))
 
         original_id = parent_id if parent_id else self.parent_id
 
diff --git a/tests/rest/media/v1/test_media_storage.py b/tests/rest/media/v1/test_media_storage.py
index 1ca648ef2b..aefe648bdb 100644
--- a/tests/rest/media/v1/test_media_storage.py
+++ b/tests/rest/media/v1/test_media_storage.py
@@ -20,9 +20,9 @@ import tempfile
 from binascii import unhexlify
 from io import BytesIO
 from typing import Optional
+from urllib import parse
 
 from mock import Mock
-from six.moves.urllib import parse
 
 import attr
 import PIL.Image as Image
diff --git a/tests/server.py b/tests/server.py
index 1644710aa0..a5e57c52fa 100644
--- a/tests/server.py
+++ b/tests/server.py
@@ -2,8 +2,6 @@ import json
 import logging
 from io import BytesIO
 
-from six import text_type
-
 import attr
 from zope.interface import implementer
 
@@ -174,7 +172,7 @@ def make_request(
     if not path.startswith(b"/"):
         path = b"/" + path
 
-    if isinstance(content, text_type):
+    if isinstance(content, str):
         content = content.encode("utf8")
 
     site = FakeSite()
diff --git a/tests/state/test_v2.py b/tests/state/test_v2.py
index a44960203e..cdc347bc53 100644
--- a/tests/state/test_v2.py
+++ b/tests/state/test_v2.py
@@ -15,8 +15,6 @@
 
 import itertools
 
-from six.moves import zip
-
 import attr
 
 from synapse.api.constants import EventTypes, JoinRules, Membership
diff --git a/tests/test_server.py b/tests/test_server.py
index adae3c6e08..3f6f468e5b 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -14,8 +14,7 @@
 
 import logging
 import re
-
-from six import StringIO
+from io import StringIO
 
 from twisted.internet.defer import Deferred
 from twisted.python.failure import Failure
diff --git a/tests/test_terms_auth.py b/tests/test_terms_auth.py
index 5c2817cf28..b89798336c 100644
--- a/tests/test_terms_auth.py
+++ b/tests/test_terms_auth.py
@@ -14,7 +14,6 @@
 
 import json
 
-import six
 from mock import Mock
 
 from twisted.test.proto_helpers import MemoryReactorClock
@@ -60,7 +59,7 @@ class TermsTestCase(unittest.HomeserverTestCase):
         self.assertEquals(channel.result["code"], b"401", channel.result)
 
         self.assertTrue(channel.json_body is not None)
-        self.assertIsInstance(channel.json_body["session"], six.text_type)
+        self.assertIsInstance(channel.json_body["session"], str)
 
         self.assertIsInstance(channel.json_body["flows"], list)
         for flow in channel.json_body["flows"]:
@@ -125,6 +124,6 @@ class TermsTestCase(unittest.HomeserverTestCase):
         self.assertEquals(channel.result["code"], b"200", channel.result)
 
         self.assertTrue(channel.json_body is not None)
-        self.assertIsInstance(channel.json_body["user_id"], six.text_type)
-        self.assertIsInstance(channel.json_body["access_token"], six.text_type)
-        self.assertIsInstance(channel.json_body["device_id"], six.text_type)
+        self.assertIsInstance(channel.json_body["user_id"], str)
+        self.assertIsInstance(channel.json_body["access_token"], str)
+        self.assertIsInstance(channel.json_body["device_id"], str)
diff --git a/tests/util/test_file_consumer.py b/tests/util/test_file_consumer.py
index e90e08d1c0..8d6627ec33 100644
--- a/tests/util/test_file_consumer.py
+++ b/tests/util/test_file_consumer.py
@@ -15,9 +15,9 @@
 
 
 import threading
+from io import StringIO
 
 from mock import NonCallableMock
-from six import StringIO
 
 from twisted.internet import defer, reactor
 
diff --git a/tests/util/test_linearizer.py b/tests/util/test_linearizer.py
index ca3858b184..0e52811948 100644
--- a/tests/util/test_linearizer.py
+++ b/tests/util/test_linearizer.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from six.moves import range
-
 from twisted.internet import defer, reactor
 from twisted.internet.defer import CancelledError
 
diff --git a/tests/utils.py b/tests/utils.py
index 7ba8a31ff3..4d17355a5c 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -21,9 +21,9 @@ import time
 import uuid
 import warnings
 from inspect import getcallargs
+from urllib import parse as urlparse
 
 from mock import Mock, patch
-from six.moves.urllib import parse as urlparse
 
 from twisted.internet import defer, reactor