Code cleanup in rabbitmq backend.

huey/backends/rabbitmq_backend.py

@@ -33,40 +33,49 @@ def __init__(self, name, **connection):
         super(RabbitQueue, self).__init__(name, **connection)
 
         self.queue_name = 'huey.rabbit.%s' % clean_name(name)
-        credentials = pika.PlainCredentials(connection.get('username', 'guest'),
-                                            connection.get('password', 'guest'))
-        self.conn = pika.BlockingConnection(pika.ConnectionParameters(host=connection.get('host', 'localhost'),
-                                                                      port=connection.get('port', 5672),
-                                                                      credentials=credentials,
-                                                                      virtual_host=connection.get('vhost', '/'),
-                                                                      ssl=connection.get('ssl', False)))
+        credentials = pika.PlainCredentials(
+            connection.get('username', 'guest'),
+            connection.get('password', 'guest'))
+        connection_params = pika.ConnectionParameters(
+            host=connection.get('host', 'localhost'),
+            port=connection.get('port', 5672),
+            credentials=credentials,
+            virtual_host=connection.get('vhost', '/'),
+            ssl=connection.get('ssl', False))
+
+        self.conn = pika.BlockingConnection(connection_params)
         self.channel = self.conn.channel()
         self.channel.queue_declare(self.queue_name, durable=True)
 
     def write(self, data):
-        self.channel.basic_publish(exchange='',
-                                   routing_key=self.queue_name,
-                                   body=data)
+        self.channel.basic_publish(
+            exchange='',
+            routing_key=self.queue_name,
+            body=data)
 
     def read(self):
-        data = self.get_data_from_queue(self.queue_name)
-        return data
+        return self.get_data_from_queue(self.queue_name)
 
     def remove(self, data):
-        #This is not something you usually do in rabbit,  this is the only operation, which is not atomic, but
-        #this "hack" should do the trick
+        # This is not something you usually do in rabbit, this is the only
+        # operation, which is not atomic, but this "hack" should do the trick.
         amount = 0
         idx = 0
         qlen = len(self)
-        for method_frame, properties, body in self.channel.consume(self.queue_name, ):
+
+        for method_frame, _, body in self.channel.consume(self.queue_name):
             idx += 1
             if body == data:
                 self.channel.basic_ack(method_frame.delivery_tag)
                 amount += 1
             else:
-                self.channel.basic_nack(method_frame.delivery_tag, requeue=True)
+                self.channel.basic_nack(
+                    method_frame.delivery_tag,
+                    requeue=True)
+
             if idx >= qlen:
                 break
+
         self.channel.cancel()
         return amount
 
@@ -75,15 +84,15 @@ def flush(self):
         return True
 
     def __len__(self):
-        q = self.channel.queue_declare(self.queue_name, durable=True)
-        q_len = q.method.message_count
-        return q_len
+        queue = self.channel.queue_declare(self.queue_name, durable=True)
+        return queue.method.message_count
 
     def get_data_from_queue(self, queue):
         data = None
         if len(self) == 0:
             return None
-        for method_frame, properties, body in self.channel.consume(queue):
+
+        for method_frame, _, body in self.channel.consume(queue):
             data = body
             self.channel.basic_ack(method_frame.delivery_tag)
             break
@@ -110,32 +119,35 @@ def read(self):
 class RabbitEventEmitter(BaseEventEmitter):
     def __init__(self, channel, **connection):
         super(RabbitEventEmitter, self).__init__(channel, **connection)
-        credentials = pika.PlainCredentials(connection.get('username', 'guest'),
-                                            connection.get('password', 'guest'))
-        self.conn = pika.BlockingConnection(pika.ConnectionParameters(host=connection.get('host', 'localhost'),
-                                                                      port=connection.get('port', 5672),
-                                                                      credentials=credentials,
-                                                                      virtual_host=connection.get('vhost', '/'),
-                                                                      ssl=connection.get('ssl', False)))
+        credentials = pika.PlainCredentials(
+            connection.get('username', 'guest'),
+            connection.get('password', 'guest'))
+        connection_params = pika.ConnectionParameters(
+            host=connection.get('host', 'localhost'),
+            port=connection.get('port', 5672),
+            credentials=credentials,
+            virtual_host=connection.get('vhost', '/'),
+            ssl=connection.get('ssl', False))
+
+        self.conn = pika.BlockingConnection(connection_params)
         self.channel = self.conn.channel()
         self.exchange_name = 'huey.events'
-        self.channel.exchange_declare(exchange=self.exchange_name,
-                                      type='fanout',
-                                      auto_delete=False,
-                                      durable=True)
+        self.channel.exchange_declare(
+            exchange=self.exchange_name,
+            type='fanout',
+            auto_delete=False,
+            durable=True)
 
     def emit(self, message):
         properties = pika.BasicProperties(
             content_type="text/plain",
-            delivery_mode=2
-        )
+            delivery_mode=2)
+
         self.channel.basic_publish(
             exchange=self.exchange_name,
             routing_key='',
             body=message,
-            properties=properties
-        )
+            properties=properties)
 
 
-Components = (RabbitBlockingQueue, RabbitQueue,
-              RabbitEventEmitter)
+Components = (RabbitBlockingQueue, None, None, RabbitEventEmitter)