Run pyupgrade to clean up Python 2 syntaxes

Update all .py source files by
 $ pyupgrade --py3-only $(git ls-files | grep ".py$")
to modernize the code according to Python 3 syntaxes.

Also add the pyupgrade hook to pre-commit to avoid merging additional
Python 2 syntaxes.

Change-Id: Ie3d3d797fc8b773e23d01e4b798a1d77feb0b475

.pre-commit-config.yaml

@@ -31,3 +31,8 @@ repos:
     hooks:
       - id: doc8
         files: doc/source/.*\.rst$
+  - repo: https://github.com/asottile/pyupgrade
+    rev: v3.18.0
+    hooks:
+      - id: pyupgrade
+        args: [--py3-only]

futurist/_futures.py

@@ -36,7 +36,7 @@ class RejectedSubmission(Exception):
 Future = _futures.Future
 
 
-class _Gatherer(object):
+class _Gatherer:
     def __init__(self, submit_func, lock_factory, start_before_submit=False):
         self._submit_func = submit_func
         self._stats_lock = lock_factory()
@@ -198,14 +198,14 @@ class ProcessPoolExecutor(_process.ProcessPoolExecutor):
     def __init__(self, max_workers=None):
         if max_workers is None:
             max_workers = _utils.get_optimal_process_count()
-        super(ProcessPoolExecutor, self).__init__(max_workers=max_workers)
+        super().__init__(max_workers=max_workers)
         if self._max_workers <= 0:
             raise ValueError("Max workers must be greater than zero")
         self._gatherer = _Gatherer(
             # Since our submit will use this gatherer we have to reference
             # the parent submit, bound to this instance (which is what we
             # really want to use anyway).
-            super(ProcessPoolExecutor, self).submit,
+            super().submit,
             self.threading.lock_object)
 
     @property
@@ -303,7 +303,7 @@ class GreenFuture(Future):
     __doc__ = Future.__doc__
 
     def __init__(self):
-        super(GreenFuture, self).__init__()
+        super().__init__()
         if not _utils.EVENTLET_AVAILABLE:
             raise RuntimeError('Eventlet is needed to use a green future')
         # NOTE(harlowja): replace the built-in condition with a greenthread
@@ -415,7 +415,7 @@ class GreenThreadPoolExecutor(_futures.Executor):
             self._pool.waitall()
 
 
-class ExecutorStatistics(object):
+class ExecutorStatistics:
     """Holds *immutable* information about a executors executions."""
 
     __slots__ = ['_failures', '_executed', '_runtime', '_cancelled']

futurist/_green.py

@@ -32,7 +32,7 @@ if _utils.EVENTLET_AVAILABLE:
     Queue = greenqueue.Queue
     is_monkey_patched = greenpatcher.is_monkey_patched
 
-    class GreenThreading(object):
+    class GreenThreading:
 
         @staticmethod
         def event_object(*args, **kwargs):
@@ -58,7 +58,7 @@ else:
     is_monkey_patched = lambda mod: False
 
 
-class GreenWorker(object):
+class GreenWorker:
     def __init__(self, work, work_queue):
         self.work = work
         self.work_queue = work_queue

futurist/_thread.py

@@ -16,7 +16,7 @@ import threading
 import weakref
 
 
-class Threading(object):
+class Threading:
 
     @staticmethod
     def event_object(*args, **kwargs):
@@ -44,7 +44,7 @@ class ThreadWorker(threading.Thread):
     MAX_IDLE_FOR = 1
 
     def __init__(self, executor, work_queue):
-        super(ThreadWorker, self).__init__()
+        super().__init__()
         self.work_queue = work_queue
         self.should_stop = False
         self.idle = False

futurist/_utils.py

@@ -29,7 +29,7 @@ except ImportError:
     EVENTLET_AVAILABLE = False
 
 
-class WorkItem(object):
+class WorkItem:
     """A thing to be executed by a executor."""
 
     def __init__(self, future, fn, args, kwargs):
@@ -62,7 +62,7 @@ class WorkItem(object):
                 del exc_type, exc_value, exc_tb
 
 
-class Failure(object):
+class Failure:
     """Object that captures a exception (and its associated information)."""
 
     def __init__(self, retain_tb):
@@ -139,7 +139,7 @@ def get_optimal_process_count(default=1):
         return default
 
 
-class Barrier(object):
+class Barrier:
     """A class that ensures active <= 0 occur before unblocking."""
 
     def __init__(self, cond_cls=threading.Condition):

futurist/periodics.py

@@ -64,7 +64,7 @@ class Work(collections.namedtuple("Work",
         return self.callback(*self.args, **self.kwargs)
 
 
-class Watcher(object):
+class Watcher:
     """A **read-only** object representing a periodic callback's activities."""
 
     def __init__(self, metrics, work):
@@ -238,7 +238,7 @@ def _now_plus_periodicity(cb, now):
     return how_often + now
 
 
-class _Schedule(object):
+class _Schedule:
     """Internal heap-based structure that maintains the schedule/ordering.
 
     This stores a heap composed of the following ``(next_run, index)`` where
@@ -278,7 +278,7 @@ def _on_failure_log(log, cb, kind, spacing, exc_info, traceback=None):
                   " seconds):\n%s", kind, cb_name, spacing, traceback)
 
 
-class _Runner(object):
+class _Runner:
     def __init__(self, now_func, retain_traceback=True):
         self.now_func = now_func
         self.retain_traceback = retain_traceback
@@ -316,7 +316,7 @@ def _build(now_func, works, next_run_scheduler):
 _SCHEDULE_RETRY_EXCEPTIONS = (RuntimeError, futurist.RejectedSubmission)
 
 
-class ExecutorFactory(object):
+class ExecutorFactory:
     """Base class for any executor factory."""
 
     shutdown = True
@@ -338,7 +338,7 @@ class ExistingExecutor(ExecutorFactory):
         return self._executor
 
 
-class PeriodicWorker(object):
+class PeriodicWorker:
     """Calls a collection of callables periodically (sleeping as needed...).
 
     NOTE(harlowja): typically the :py:meth:`.start` method is executed in a

futurist/tests/test_executors.py

@@ -54,11 +54,11 @@ class TestExecutors(testscenarios.TestWithScenarios, base.TestCase):
     ]
 
     def setUp(self):
-        super(TestExecutors, self).setUp()
+        super().setUp()
         self.executor = self.executor_cls(**self.executor_kwargs)
 
     def tearDown(self):
-        super(TestExecutors, self).tearDown()
+        super().tearDown()
         self.executor.shutdown()
         self.executor = None
 
@@ -155,7 +155,7 @@ class TestRejection(testscenarios.TestWithScenarios, base.TestCase):
     ]
 
     def setUp(self):
-        super(TestRejection, self).setUp()
+        super().setUp()
         self.executor = self.executor_cls(**self.executor_kwargs)
         self.addCleanup(self.executor.shutdown, wait=True)
 

futurist/tests/test_periodics.py

@@ -428,7 +428,7 @@ class TestPeriodics(testscenarios.TestWithScenarios, base.TestCase):
     def test_create_with_arguments(self):
         m = mock.Mock()
 
-        class Object(object):
+        class Object:
             @periodics.periodic(0.5)
             def func1(self, *args, **kwargs):
                 m(*args, **kwargs)
@@ -533,7 +533,7 @@ class RejectingExecutor(futurist.GreenThreadPoolExecutor):
 
     def __init__(self):
         self._rejections_count = 0
-        super(RejectingExecutor, self).__init__(check_and_reject=self._reject)
+        super().__init__(check_and_reject=self._reject)
 
 
 class TestPformat(base.TestCase):

futurist/tests/test_waiters.py

@@ -48,11 +48,11 @@ class TestWaiters(testscenarios.TestWithScenarios, base.TestCase):
     ]
 
     def setUp(self):
-        super(TestWaiters, self).setUp()
+        super().setUp()
         self.executor = self.executor_cls(**self.executor_kwargs)
 
     def tearDown(self):
-        super(TestWaiters, self).tearDown()
+        super().tearDown()
         self.executor.shutdown()
         self.executor = None
 

futurist/waiters.py

@@ -113,7 +113,7 @@ def wait_for_any(fs, timeout=None):
                      'wait_for_any', timeout=timeout)
 
 
-class _AllGreenWaiter(object):
+class _AllGreenWaiter:
     """Provides the event that ``_wait_for_all_green`` blocks on."""
 
     def __init__(self, pending):
@@ -137,7 +137,7 @@ class _AllGreenWaiter(object):
         self._decrement_pending()
 
 
-class _AnyGreenWaiter(object):
+class _AnyGreenWaiter:
     """Provides the event that ``_wait_for_any_green`` blocks on."""
 
     def __init__(self):