Replace 'async' keyword with 'is_async' for Queue objects (#977)

* Replaced async keyword with is_async in the Queue class to fix reserved keyword syntax errors in Python 3.7

* Updated tests to use is_async keyword when instantiating Queue objects

* Updated docs to reference is_async keyword for Queue objects

* Updated tox.ini, setup.py and .travis.yml with references to Python 3.7

8 files changed, 28 insertions, 22 deletions

diff --git a/.travis.yml b/.travis.yml
index fb32d33..225c626 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,7 @@ python:
   - "3.4"
   - "3.5"
   - "3.6"
-  - "3.6-dev"
+  - "3.7-dev"
   - "pypy"
 install:
   - pip install -e .
diff --git a/docs/docs/index.md b/docs/docs/index.md
index 3934ab4..5a1fac6 100644
--- a/docs/docs/index.md
+++ b/docs/docs/index.md
@@ -65,7 +65,7 @@ job function.
     and marked as `failed`. Its default unit is second and it can be an integer or a string representing an integer(e.g.  `2`, `'2'`). Furthermore, it can be a string with specify unit including hour, minute, second(e.g. `'1h'`, `'3m'`, `'5s'`).
 * `result_ttl` specifies the expiry time of the key where the job result will
   be stored
-* `ttl` specifies the maximum queued time of the job before it'll be cancelled. 
+* `ttl` specifies the maximum queued time of the job before it'll be cancelled.
   If you specify a value of `-1` you indicate an infinite job ttl and it will run indefinitely
 * `depends_on` specifies another job (or job id) that must complete before this
   job will be queued
@@ -104,7 +104,7 @@ from rq import Queue
 from redis import Redis
 
 redis_conn = Redis()
-q = Queue(connection=redis_conn) 
+q = Queue(connection=redis_conn)
 
 # Getting the number of jobs in the queue
 print len(q)
@@ -168,10 +168,10 @@ print job.result
 
 For testing purposes, you can enqueue jobs without delegating the actual
 execution to a worker (available since version 0.3.1). To do this, pass the
-`async=False` argument into the Queue constructor:
+`is_async=False` argument into the Queue constructor:
 
 {% highlight pycon %}
->>> q = Queue('low', async=False, connection=my_redis_conn)
+>>> q = Queue('low', is_async=False, connection=my_redis_conn)
 >>> job = q.enqueue(fib, 8)
 >>> job.result
 21
diff --git a/docs/docs/testing.md b/docs/docs/testing.md
index f2378a5..bfa4e88 100644
--- a/docs/docs/testing.md
+++ b/docs/docs/testing.md
@@ -5,7 +5,7 @@ layout: docs
 
 ## Workers inside unit tests
 
-You may wish to include your RQ tasks inside unit tests. However many frameworks (such as Django) use in-memory databases which do not play nicely with the default `fork()` behaviour of RQ. 
+You may wish to include your RQ tasks inside unit tests. However many frameworks (such as Django) use in-memory databases which do not play nicely with the default `fork()` behaviour of RQ.
 
 Therefore, you must use the SimpleWorker class to avoid fork();
 
@@ -23,19 +23,19 @@ worker.work(burst=True)  # Runs enqueued job
 
 ## Running Jobs in unit tests
 
-Another solution for testing purposes is to use the `async=False` queue
+Another solution for testing purposes is to use the `is_async=False` queue
 parameter, that instructs it to instantly perform the job in the same
-thread instead of dispatching it to the workers. Workers are not required 
+thread instead of dispatching it to the workers. Workers are not required
 anymore.
 Additionally, we can use fakeredis to mock a redis instance, so we don't have to
-run a redis server separately. The instance of the fake redis server can 
+run a redis server separately. The instance of the fake redis server can
 be directly passed as the connection argument to the queue:
 
 {% highlight python %}
 from fakeredis import FakeStrictRedis
 from rq import Queue
 
-queue = Queue(async=False, connection=FakeStrictRedis())
+queue = Queue(is_async=False, connection=FakeStrictRedis())
 job = queue.enqueue(my_long_running_job)
 assert job.is_finished
-{% endhighlight %}
\ No newline at end of file
+{% endhighlight %}
diff --git a/rq/queue.py b/rq/queue.py
index 62db2f4..84a938a 100644
--- a/rq/queue.py
+++ b/rq/queue.py
@@ -3,6 +3,7 @@ from __future__ import (absolute_import, division, print_function,
                         unicode_literals)
 
 import uuid
+import warnings
 
 from redis import WatchError
 
@@ -58,13 +59,17 @@ class Queue(object):
         return cls(name, connection=connection, job_class=job_class)
 
     def __init__(self, name='default', default_timeout=None, connection=None,
-                 async=True, job_class=None):
+                 is_async=True, job_class=None, **kwargs):
         self.connection = resolve_connection(connection)
         prefix = self.redis_queue_namespace_prefix
         self.name = name
         self._key = '{0}{1}'.format(prefix, name)
         self._default_timeout = parse_timeout(default_timeout)
-        self._async = async
+        self._is_async = is_async
+
+        if 'async' in kwargs:
+            self._is_async = kwargs['async']
+            warnings.warn('The `async` keyword is deprecated. Use `is_async` instead', DeprecationWarning)
 
         # override class attribute job_class if one was passed
         if job_class is not None:
@@ -303,7 +308,7 @@ class Queue(object):
     def enqueue_job(self, job, pipeline=None, at_front=False):
         """Enqueues a job for delayed execution.
 
-        If Queue is instantiated with async=False, job is executed immediately.
+        If Queue is instantiated with is_async=False, job is executed immediately.
         """
         pipe = pipeline if pipeline is not None else self.connection._pipeline()
 
@@ -319,13 +324,13 @@ class Queue(object):
         job.save(pipeline=pipe)
         job.cleanup(ttl=job.ttl, pipeline=pipe)
 
-        if self._async:
+        if self._is_async:
             self.push_job_id(job.id, pipeline=pipe, at_front=at_front)
 
         if pipeline is None:
             pipe.execute()
 
-        if not self._async:
+        if not self._is_async:
             job = self.run_job(job)
 
         return job
diff --git a/setup.py b/setup.py
index f22355a..3c425c7 100644
--- a/setup.py
+++ b/setup.py
@@ -72,6 +72,7 @@ setup(
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
         'Topic :: Software Development :: Libraries :: Python Modules',
         'Topic :: Internet',
         'Topic :: Scientific/Engineering',
diff --git a/tests/test_job.py b/tests/test_job.py
index 63e4564..d940f6d 100644
--- a/tests/test_job.py
+++ b/tests/test_job.py
@@ -389,17 +389,17 @@ class TestJob(RQTestCase):
         assert get_failed_queue(self.testconn).count == 0
 
     def test_job_access_within_synchronous_job_function(self):
-        queue = Queue(async=False)
+        queue = Queue(is_async=False)
         queue.enqueue(fixtures.access_self)
 
     def test_job_async_status_finished(self):
-        queue = Queue(async=False)
+        queue = Queue(is_async=False)
         job = queue.enqueue(fixtures.say_hello)
         self.assertEqual(job.result, 'Hi there, Stranger!')
         self.assertEqual(job.get_status(), JobStatus.FINISHED)
 
     def test_enqueue_job_async_status_finished(self):
-        queue = Queue(async=False)
+        queue = Queue(is_async=False)
         job = Job.create(func=fixtures.say_hello)
         job = queue.enqueue_job(job)
         self.assertEqual(job.result, 'Hi there, Stranger!')
diff --git a/tests/test_queue.py b/tests/test_queue.py
index 96035c8..a2ca8c8 100644
--- a/tests/test_queue.py
+++ b/tests/test_queue.py
@@ -645,8 +645,8 @@ class TestFailedQueue(RQTestCase):
         self.assertEqual(int(job_from_queue.result_ttl), 10)
 
     def test_async_false(self):
-        """Job executes and cleaned up immediately if async=False."""
-        q = Queue(async=False)
+        """Job executes and cleaned up immediately if is_async=False."""
+        q = Queue(is_async=False)
         job = q.enqueue(some_calculation, args=(2, 3))
         self.assertEqual(job.return_value, 6)
         self.assertNotEqual(self.testconn.ttl(job.key), -1)
diff --git a/tox.ini b/tox.ini
index 93a76b9..baeba93 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist=py26,py27,py33,py34,py35,pypy,flake8
+envlist=py26,py27,py33,py34,py35,py36,py37,pypy,flake8
 
 [testenv]
 commands=py.test --cov rq --durations=5 {posargs}