Cancelable tasks: Clean-up style

celery/contrib/cancelable.py

@@ -28,9 +28,11 @@ In the consumer:
 .. code-block:: python
 
    from celery.contrib.cancelable import CancelableTask
+
    def MyLongRunningTask(CancelableTask):
+
        def run(self, **kwargs):
-           logger = self.get_logger()
+           logger = self.get_logger(**kwargs)
            results = []
            for x in xrange(100):
                # Check after every 5 loops..
@@ -38,11 +40,11 @@ In the consumer:
                    if self.is_cancelled(**kwargs):
                        # Respect the cancelled status and terminate
                        # gracefully
-                       logger.warning('Task cancelled.')
+                       logger.warning("Task cancelled.")
                        return None
                y = do_something_expensive(x)
                results.append(y)
-           logger.info('Task finished.')
+           logger.info("Task finished.")
            return results
 
 
@@ -51,7 +53,9 @@ In the producer:
 .. code-block:: python
 
    from myproject.tasks import MyLongRunningTask
+
    def myview(request):
+
        async_result = MyLongRunningTask.delay()
        # async_result is of type CancelableAsyncResult
 
@@ -61,16 +65,15 @@ In the producer:
 
        ...
 
-After the `async_result.cancel()` call, the task execution is not
+After the ``async_result.cancel()`` call, the task execution is not
 aborted immediately. In fact, it is not guaranteed to abort at all. Keep
-checking the `async_result` status, or call `async_result.wait()` to
+checking the ``async_result`` status, or call ``async_result.wait()`` to
 have it block until the task is finished.
 
 """
-
 from celery.task.base import Task
 from celery.result import AsyncResult
-from multiprocessing import Process, Event
+
 
 """ Task States
 
@@ -82,11 +85,12 @@ from multiprocessing import Process, Event
 """
 CANCELLED = "CANCELLED"
 
+
 class CancelableAsyncResult(AsyncResult):
     """Represents a cancelable result.
 
-    Specifically, this gives the AsyncResult a cancel() method, which sets
-    the state of the underlying Task to "CANCELLED".
+    Specifically, this gives the ``AsyncResult`` a :meth:`cancel()` method,
+    which sets the state of the underlying Task to ``"CANCELLED"``.
 
     """
 
@@ -105,8 +109,10 @@ class CancelableAsyncResult(AsyncResult):
         all).
 
         """
-        # TODO: store_result requires all four arguments to be set, but only status should be updated here
-        return self.backend.store_result(self.task_id, result=None, status=CANCELLED, traceback=None)
+        # TODO: store_result requires all four arguments to be set,
+        # but only status should be updated here
+        return self.backend.store_result(self.task_id, result=None,
+                                         status=CANCELLED, traceback=None)
 
 
 class CancelableTask(Task):
@@ -137,8 +143,7 @@ class CancelableTask(Task):
         often (for performance).
 
         """
-        result = self.AsyncResult(kwargs['task_id'])
+        result = self.AsyncResult(kwargs["task_id"])
         if not isinstance(result, CancelableAsyncResult):
             return False
         return result.is_cancelled()
-

celery/tests/test_task_cancelable.py

@@ -1,18 +1,22 @@
 import unittest2 as unittest
 
-from celery.contrib.cancelable import CancelableTask, CancelableAsyncResult, CANCELLED
+from celery.contrib.cancelable import CANCELLED
+from celery.contrib.cancelable import CancelableTask, CancelableAsyncResult
+
 
 class MyCancelableTask(CancelableTask):
+
     def run(self, **kwargs):
         return True
 
+
 class TestCancelableTask(unittest.TestCase):
+
     def test_async_result_is_cancelable(self):
         t = MyCancelableTask()
         result = t.apply_async()
         tid = result.task_id
-        self.assertIsInstance(t.AsyncResult(tid), \
-                              CancelableAsyncResult)
+        self.assertIsInstance(t.AsyncResult(tid), CancelableAsyncResult)
 
     def test_is_not_cancelled(self):
         t = MyCancelableTask()
@@ -26,4 +30,3 @@ class TestCancelableTask(unittest.TestCase):
         result.cancel()
         tid = result.task_id
         self.assertTrue(t.is_cancelled(task_id=tid))
-