Fix pep8 errors using the Django core's flake8 preset

channels/__init__.py

@@ -16,4 +16,4 @@ channel_backends = BackendManager(
 default_app_config = 'channels.apps.ChannelsConfig'
 
 # Promote channel to top-level (down here to avoid circular import errs)
-from .channel import Channel, Group
+from .channel import Channel, Group  # NOQA

channels/apps.py

@@ -1,5 +1,6 @@
 from django.apps import AppConfig
 
+
 class ChannelsConfig(AppConfig):
 
     name = "channels"

channels/backends/__init__.py

@@ -20,10 +20,12 @@ class BackendManager(object):
             backend_class = import_string(self.configs[name]['BACKEND'])
         except KeyError:
             raise InvalidChannelBackendError("No BACKEND specified for %s" % name)
-        except ImportError as e:
+        except ImportError:
-            raise InvalidChannelBackendError("Cannot import BACKEND %r specified for %s" % (self.configs[name]['BACKEND'], name))
+            raise InvalidChannelBackendError("Cannot import BACKEND %r specified for %s" %
+                                             (self.configs[name]['BACKEND'], name))
         # Initialise and pass config
-        instance = backend_class(**{k.lower(): v for k, v in self.configs[name].items() if k != "BACKEND"})
+        instance = backend_class(
+            **{k.lower(): v for k, v in self.configs[name].items() if k != "BACKEND"})
         instance.alias = name
         return instance
 

channels/backends/database.py

@@ -1,4 +1,3 @@
-import time
 import json
 import datetime
 
@@ -39,6 +38,7 @@ class DatabaseChannelBackend(BaseChannelBackend):
             channel = models.CharField(max_length=200, db_index=True)
             content = models.TextField()
             expiry = models.DateTimeField(db_index=True)
+
             class Meta:
                 apps = Apps()
                 app_label = "channels"
@@ -60,6 +60,7 @@ class DatabaseChannelBackend(BaseChannelBackend):
             group = models.CharField(max_length=200)
             channel = models.CharField(max_length=200)
             expiry = models.DateTimeField(db_index=True)
+
             class Meta:
                 apps = Apps()
                 app_label = "channels"
@@ -81,6 +82,7 @@ class DatabaseChannelBackend(BaseChannelBackend):
         class Lock(models.Model):
             channel = models.CharField(max_length=200, unique=True)
             expiry = models.DateTimeField(db_index=True)
+
             class Meta:
                 apps = Apps()
                 app_label = "channels"

channels/backends/memory.py

@@ -7,6 +7,7 @@ queues = {}
 groups = {}
 locks = set()
 
+
 class InMemoryChannelBackend(BaseChannelBackend):
     """
     In-memory channel implementation. Intended only for use with threading,

channels/backends/redis_py.py

@@ -1,6 +1,5 @@
 import time
 import json
-import datetime
 import math
 import redis
 import random
@@ -64,7 +63,11 @@ class RedisChannelBackend(BaseChannelBackend):
     def send(self, channel, message):
         # if channel is no str (=> bytes) convert it
         if not isinstance(channel, str):
-            channel = channel.decode('utf-8')
+            channel = channel.decode("utf-8")
+        # Write out message into expiring key (avoids big items in list)
+        # TODO: Use extended set, drop support for older redis?
+        key = self.prefix + uuid.uuid4().hex
+
         # Pick a connection to the right server - consistent for response
         # channels, random for normal channels
         if channel.startswith("!"):
@@ -72,9 +75,7 @@ class RedisChannelBackend(BaseChannelBackend):
             connection = self.connection(index)
         else:
             connection = self.connection(None)
-        # Write out message into expiring key (avoids big items in list)
+
-        # TODO: Use extended set, drop support for older redis?
-        key = self.prefix + uuid.uuid4().hex
         connection.set(
             key,
             json.dumps(message),

channels/decorators.py

@@ -18,7 +18,8 @@ def linearize(func):
     def inner(message, *args, **kwargs):
         # Make sure there's a reply channel
         if not message.reply_channel:
-            raise ValueError("No reply_channel sent to consumer; @no_overlap can only be used on messages containing it.")
+            raise ValueError("No reply_channel sent to consumer; "
+                             "@no_overlap can only be used on messages containing it.")
         # Get the lock, or re-queue
         locked = message.channel_backend.lock_channel(message.reply_channel)
         if not locked:
@@ -43,10 +44,12 @@ def channel_session(func):
     def inner(message, *args, **kwargs):
         # Make sure there's a reply_channel
         if not message.reply_channel:
-            raise ValueError("No reply_channel sent to consumer; @channel_session can only be used on messages containing it.")
+            raise ValueError("No reply_channel sent to consumer; "
+                             "@channel_session can only be used on messages containing it.")
         # Make sure there's NOT a channel_session already
         if hasattr(message, "channel_session"):
-            raise ValueError("channel_session decorator wrapped inside another channel_session decorator")
+            raise ValueError("channel_session decorator wrapped "
+                             "inside another channel_session decorator")
         # Turn the reply_channel into a valid session key length thing.
         # We take the last 24 bytes verbatim, as these are the random section,
         # and then hash the remaining ones onto the start, and add a prefix

channels/management/commands/runserver.py

@@ -1,7 +1,6 @@
 import threading
 
 from django.core.management.commands.runserver import Command as RunserverCommand
-
 from channels import channel_backends, DEFAULT_CHANNEL_BACKEND
 from channels.adapters import UrlConsumer
 from channels.interfaces.wsgi import WSGIInterface

channels/management/commands/runworker.py

@@ -14,7 +14,8 @@ class Command(BaseCommand):
         channel_backend = channel_backends[DEFAULT_CHANNEL_BACKEND]
         if channel_backend.local_only:
             raise CommandError(
-                "You have a process-local channel backend configured, and so cannot run separate workers.\n"
+                "You have a process-local channel backend configured, "
+                "and so cannot run separate workers.\n"
                 "Configure a network-based backend in CHANNEL_BACKENDS to use this command."
             )
         # Launch a worker

channels/management/commands/runwsserver.py

@@ -23,7 +23,7 @@ class Command(BaseCommand):
         # Run the interface
         port = int(options.get("port", None) or 9000)
         try:
-            import asyncio
+            import asyncio  # NOQA
         except ImportError:
             from channels.interfaces.websocket_twisted import WebsocketTwistedInterface
             self.logger.info("Running Twisted/Autobahn WebSocket interface server")

channels/request.py

@@ -1,7 +1,6 @@
 from django.http import HttpRequest
 from django.utils.datastructures import MultiValueDict
 from django.http.request import QueryDict
-from django.conf import settings
 
 
 def encode_request(request):

channels/tests/settings.py

@@ -5,3 +5,5 @@ DATABASES = {
         'ENGINE': 'django.db.backends.sqlite3',
     }
 }
+
+MIDDLEWARE_CLASSES = []

channels/tests/test_backends.py

@@ -1,7 +1,6 @@
 from __future__ import unicode_literals
 
 from django.test import TestCase
-from ..channel import Channel
 from ..backends.database import DatabaseChannelBackend
 from ..backends.redis_py import RedisChannelBackend
 from ..backends.memory import InMemoryChannelBackend

tox.ini

@@ -1,7 +1,14 @@
 [tox]
 skipsdist = True
 envlist =
-    {py27,py35}-django-{16,17,18}
+    {py27}-django-{17,18,19}
+    {py35}-django-{18,19}
+    {py27,py35}-flake8
+
+[flake8]
+exclude = venv/*,tox/*,docs/*
+ignore = E123,E128,E402,W503,E731,W601
+max-line-length = 119
 
 [testenv]
 setenv =
@@ -9,8 +16,11 @@ setenv =
 deps =
     six
     redis==2.10.5
+    flake8: flake8
     django-16: Django>=1.6,<1.7
     django-17: Django>=1.7,<1.8
     django-18: Django>=1.8,<1.9
+    django-19: Django==1.9b1
 commands =
-    python {toxinidir}/runtests.py
+    flake8: flake8
+    django: python {toxinidir}/runtests.py