Merge pull request #678 from a-ungurianu/devx/bye_bye_six

refactor: Remove vestiges of python2 support

13 files changed, 71 insertions, 197 deletions

diff --git a/kazoo/client.py b/kazoo/client.py
index bf1ec8f..27b7c38 100644
--- a/kazoo/client.py
+++ b/kazoo/client.py
@@ -7,8 +7,6 @@ from os.path import split
 import re
 import warnings
 
-import six
-
 from kazoo.exceptions import (
     AuthFailedError,
     ConfigurationError,
@@ -66,9 +64,6 @@ from kazoo.recipe.queue import Queue, LockingQueue
 from kazoo.recipe.watchers import ChildrenWatch, DataWatch
 
 
-string_types = six.string_types
-bytes_types = (six.binary_type,)
-
 CLOSED_STATES = (
     KeeperState.EXPIRED_SESSION,
     KeeperState.AUTH_FAILED,
@@ -415,10 +410,10 @@ class KazooClient(object):
 
     def _reset_watchers(self):
         watchers = []
-        for child_watchers in six.itervalues(self._child_watchers):
+        for child_watchers in self._child_watchers.values():
             watchers.extend(child_watchers)
 
-        for data_watchers in six.itervalues(self._data_watchers):
+        for data_watchers in self._data_watchers.values():
             watchers.extend(data_watchers)
 
         self._child_watchers = defaultdict(set)
@@ -821,7 +816,7 @@ class KazooClient(object):
         version = _try_fetch()
         if _is_valid(version):
             return version
-        for _i in six.moves.range(0, retries):
+        for _i in range(0, retries):
             version = _try_fetch()
             if _is_valid(version):
                 return version
@@ -854,9 +849,9 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(scheme, string_types):
+        if not isinstance(scheme, str):
             raise TypeError("Invalid type for 'scheme' (string expected)")
-        if not isinstance(credential, string_types):
+        if not isinstance(credential, str):
             raise TypeError("Invalid type for 'credential' (string expected)")
 
         # we need this auth data to re-authenticate on reconnect
@@ -1034,7 +1029,7 @@ class KazooClient(object):
         if acl is None and self.default_acl:
             acl = self.default_acl
 
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if acl and (
             isinstance(acl, ACL) or not isinstance(acl, (tuple, list))
@@ -1042,7 +1037,7 @@ class KazooClient(object):
             raise TypeError(
                 "Invalid type for 'acl' (acl must be a tuple/list" " of ACL's"
             )
-        if value is not None and not isinstance(value, bytes_types):
+        if value is not None and not isinstance(value, bytes):
             raise TypeError("Invalid type for 'value' (must be a byte string)")
         if not isinstance(ephemeral, bool):
             raise TypeError("Invalid type for 'ephemeral' (bool expected)")
@@ -1205,7 +1200,7 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if watch and not callable(watch):
             raise TypeError("Invalid type for 'watch' (must be a callable)")
@@ -1248,7 +1243,7 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if watch and not callable(watch):
             raise TypeError("Invalid type for 'watch' (must be a callable)")
@@ -1304,7 +1299,7 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if watch and not callable(watch):
             raise TypeError("Invalid type for 'watch' (must be a callable)")
@@ -1346,7 +1341,7 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
 
         async_result = self.handler.async_result()
@@ -1389,7 +1384,7 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if isinstance(acls, ACL) or not isinstance(acls, (tuple, list)):
             raise TypeError(
@@ -1447,9 +1442,9 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
-        if value is not None and not isinstance(value, bytes_types):
+        if value is not None and not isinstance(value, bytes):
             raise TypeError("Invalid type for 'value' (must be a byte string)")
         if not isinstance(version, int):
             raise TypeError("Invalid type for 'version' (int expected)")
@@ -1523,7 +1518,7 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if not isinstance(version, int):
             raise TypeError("Invalid type for 'version' (int expected)")
@@ -1632,11 +1627,11 @@ class KazooClient(object):
         :rtype: :class:`~kazoo.interfaces.IAsyncResult`
 
         """
-        if joining and not isinstance(joining, string_types):
+        if joining and not isinstance(joining, str):
             raise TypeError("Invalid type for 'joining' (string expected)")
-        if leaving and not isinstance(leaving, string_types):
+        if leaving and not isinstance(leaving, str):
             raise TypeError("Invalid type for 'leaving' (string expected)")
-        if new_members and not isinstance(new_members, string_types):
+        if new_members and not isinstance(new_members, str):
             raise TypeError(
                 "Invalid type for 'new_members' (string " "expected)"
             )
@@ -1690,13 +1685,13 @@ class TransactionRequest(object):
         if acl is None and self.client.default_acl:
             acl = self.client.default_acl
 
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if acl and not isinstance(acl, (tuple, list)):
             raise TypeError(
                 "Invalid type for 'acl' (acl must be a tuple/list" " of ACL's"
             )
-        if not isinstance(value, bytes_types):
+        if not isinstance(value, bytes):
             raise TypeError("Invalid type for 'value' (must be a byte string)")
         if not isinstance(ephemeral, bool):
             raise TypeError("Invalid type for 'ephemeral' (bool expected)")
@@ -1722,7 +1717,7 @@ class TransactionRequest(object):
         `recursive`.
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if not isinstance(version, int):
             raise TypeError("Invalid type for 'version' (int expected)")
@@ -1733,9 +1728,9 @@ class TransactionRequest(object):
         arguments as :meth:`KazooClient.set`.
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
-        if not isinstance(value, bytes_types):
+        if not isinstance(value, bytes):
             raise TypeError("Invalid type for 'value' (must be a byte string)")
         if not isinstance(version, int):
             raise TypeError("Invalid type for 'version' (int expected)")
@@ -1750,7 +1745,7 @@ class TransactionRequest(object):
         does not match the specified version.
 
         """
-        if not isinstance(path, string_types):
+        if not isinstance(path, str):
             raise TypeError("Invalid type for 'path' (string expected)")
         if not isinstance(version, int):
             raise TypeError("Invalid type for 'version' (int expected)")
diff --git a/kazoo/handlers/eventlet.py b/kazoo/handlers/eventlet.py
index ebf9898..8869cc5 100644
--- a/kazoo/handlers/eventlet.py
+++ b/kazoo/handlers/eventlet.py
@@ -1,6 +1,7 @@
 """A eventlet based handler."""
 from __future__ import absolute_import
 
+import atexit
 import contextlib
 import logging
 
@@ -12,7 +13,6 @@ from eventlet.green import selectors as green_selectors
 from eventlet import queue as green_queue
 
 from kazoo.handlers import utils
-import kazoo.python2atexit as python2atexit
 from kazoo.handlers.utils import selector_select
 
 LOG = logging.getLogger(__name__)
@@ -140,7 +140,7 @@ class SequentialEventletHandler(object):
             w = eventlet.spawn(self._process_callback_queue)
             self._workers.append((w, self.callback_queue))
             self._started = True
-            python2atexit.register(self.stop)
+            atexit.register(self.stop)
 
     def stop(self):
         while self._workers:
@@ -148,7 +148,7 @@ class SequentialEventletHandler(object):
             q.put(_STOP)
             w.wait()
         self._started = False
-        python2atexit.unregister(self.stop)
+        atexit.unregister(self.stop)
 
     def socket(self, *args, **kwargs):
         return utils.create_tcp_socket(green_socket)
diff --git a/kazoo/handlers/gevent.py b/kazoo/handlers/gevent.py
index 1c141bc..f36389a 100644
--- a/kazoo/handlers/gevent.py
+++ b/kazoo/handlers/gevent.py
@@ -1,6 +1,7 @@
 """A gevent based handler."""
 from __future__ import absolute_import
 
+import atexit
 import logging
 
 import gevent
@@ -13,13 +14,9 @@ import gevent.selectors
 
 from kazoo.handlers.utils import selector_select
 
-try:
-    from gevent.lock import Semaphore, RLock
-except ImportError:
-    from gevent.coros import Semaphore, RLock
+from gevent.lock import Semaphore, RLock
 
 from kazoo.handlers import utils
-from kazoo import python2atexit
 
 _using_libevent = gevent.__version__.startswith("0.")
 
@@ -104,7 +101,7 @@ class SequentialGeventHandler(object):
             for queue in (self.callback_queue,):
                 w = self._create_greenlet_worker(queue)
                 self._workers.append(w)
-            python2atexit.register(self.stop)
+            atexit.register(self.stop)
 
     def stop(self):
         """Stop the greenlet workers and empty all queues."""
@@ -124,7 +121,7 @@ class SequentialGeventHandler(object):
             # Clear the queues
             self.callback_queue = self.queue_impl()  # pragma: nocover
 
-            python2atexit.unregister(self.stop)
+            atexit.unregister(self.stop)
 
     def select(self, *args, **kwargs):
         return selector_select(
diff --git a/kazoo/handlers/threading.py b/kazoo/handlers/threading.py
index 210c31e..b9acd87 100644
--- a/kazoo/handlers/threading.py
+++ b/kazoo/handlers/threading.py
@@ -12,21 +12,16 @@ environments that use threads.
 """
 from __future__ import absolute_import
 
+import atexit
 import logging
+import queue
 import socket
 import threading
 import time
 
-import six
-
-import kazoo.python2atexit as python2atexit
 from kazoo.handlers import utils
 from kazoo.handlers.utils import selector_select
 
-try:
-    import Queue
-except ImportError:  # pragma: nocover
-    import queue as Queue
 
 # sentinel objects
 _STOP = object()
@@ -35,11 +30,11 @@ log = logging.getLogger(__name__)
 
 
 def _to_fileno(obj):
-    if isinstance(obj, six.integer_types):
+    if isinstance(obj, int):
         fd = int(obj)
     elif hasattr(obj, "fileno"):
         fd = obj.fileno()
-        if not isinstance(fd, six.integer_types):
+        if not isinstance(fd, int):
             raise TypeError("fileno() returned a non-integer")
         fd = int(fd)
     else:
@@ -98,8 +93,8 @@ class SequentialThreadingHandler(object):
     name = "sequential_threading_handler"
     timeout_exception = KazooTimeoutError
     sleep_func = staticmethod(time.sleep)
-    queue_impl = Queue.Queue
-    queue_empty = Queue.Empty
+    queue_impl = queue.Queue
+    queue_empty = queue.Empty
 
     def __init__(self):
         """Create a :class:`SequentialThreadingHandler` instance"""
@@ -113,11 +108,11 @@ class SequentialThreadingHandler(object):
     def running(self):
         return self._running
 
-    def _create_thread_worker(self, queue):
+    def _create_thread_worker(self, work_queue):
         def _thread_worker():  # pragma: nocover
             while True:
                 try:
-                    func = queue.get()
+                    func = work_queue.get()
                     try:
                         if func is _STOP:
                             break
@@ -125,7 +120,7 @@ class SequentialThreadingHandler(object):
                     except Exception:
                         log.exception("Exception in worker queue thread")
                     finally:
-                        queue.task_done()
+                        work_queue.task_done()
                         del func  # release before possible idle
                 except self.queue_empty:
                     continue
@@ -142,11 +137,11 @@ class SequentialThreadingHandler(object):
             # Spawn our worker threads, we have
             # - A callback worker for watch events to be called
             # - A completion worker for completion events to be called
-            for queue in (self.completion_queue, self.callback_queue):
-                w = self._create_thread_worker(queue)
+            for work_queue in (self.completion_queue, self.callback_queue):
+                w = self._create_thread_worker(work_queue)
                 self._workers.append(w)
             self._running = True
-            python2atexit.register(self.stop)
+            atexit.register(self.stop)
 
     def stop(self):
         """Stop the worker threads and empty all queues."""
@@ -156,8 +151,8 @@ class SequentialThreadingHandler(object):
 
             self._running = False
 
-            for queue in (self.completion_queue, self.callback_queue):
-                queue.put(_STOP)
+            for work_queue in (self.completion_queue, self.callback_queue):
+                work_queue.put(_STOP)
 
             self._workers.reverse()
             while self._workers:
@@ -167,7 +162,7 @@ class SequentialThreadingHandler(object):
             # Clear the queues
             self.callback_queue = self.queue_impl()
             self.completion_queue = self.queue_impl()
-            python2atexit.unregister(self.stop)
+            atexit.unregister(self.stop)
 
     def select(self, *args, **kwargs):
         return selector_select(*args, **kwargs)
diff --git a/kazoo/handlers/utils.py b/kazoo/handlers/utils.py
index 2717059..6b60e75 100644
--- a/kazoo/handlers/utils.py
+++ b/kazoo/handlers/utils.py
@@ -1,22 +1,15 @@
 """Kazoo handler helpers"""
 
+from collections import defaultdict
 import errno
 import functools
 import os
 import select
+import selectors
 import ssl
 import socket
 import time
 
-from collections import defaultdict
-
-import six
-
-if six.PY34:
-    import selectors
-else:
-    import selectors2 as selectors
-
 HAS_FNCTL = True
 try:
     import fcntl
@@ -363,14 +356,9 @@ def selector_select(
 ):
     """Selector-based drop-in replacement for select to overcome select
     limitation on a maximum filehandle value.
-
-    Need backport selectors2 package in python 2.
     """
     if timeout is not None:
-        if not (
-            isinstance(timeout, six.integer_types)
-            or isinstance(timeout, float)
-        ):
+        if not isinstance(timeout, (int, float)):
             raise TypeError("timeout must be a number")
         if timeout < 0:
             raise ValueError("timeout must be non-negative")
@@ -400,9 +388,9 @@ def selector_select(
 
     for info in ready:
         k, events = info
-        if events & selectors.EVENT_READ:
+        if events & selectors_module.EVENT_READ:
             revents.extend(fd_fileobjs[k.fd])
-        elif events & selectors.EVENT_WRITE:
+        elif events & selectors_module.EVENT_WRITE:
             wevents.extend(fd_fileobjs[k.fd])
 
     return revents, wevents, xevents
diff --git a/kazoo/hosts.py b/kazoo/hosts.py
index aa18805..3ece931 100644
--- a/kazoo/hosts.py
+++ b/kazoo/hosts.py
@@ -1,4 +1,4 @@
-from six.moves import urllib_parse
+import urllib.parse
 
 
 def collect_hosts(hosts):
@@ -20,7 +20,7 @@ def collect_hosts(hosts):
     for host_port in host_ports:
         # put all complexity of dealing with
         # IPv4 & IPv6 address:port on the urlsplit
-        res = urllib_parse.urlsplit("xxx://" + host_port)
+        res = urllib.parse.urlsplit("xxx://" + host_port)
         host = res.hostname
         if host is None:
             raise ValueError("bad hostname")
diff --git a/kazoo/protocol/connection.py b/kazoo/protocol/connection.py
index d7d84d1..6ed5cde 100644
--- a/kazoo/protocol/connection.py
+++ b/kazoo/protocol/connection.py
@@ -10,8 +10,6 @@ import ssl
 import sys
 import time
 
-import six
-
 from kazoo.exceptions import (
     AuthFailedError,
     ConnectionDropped,
@@ -808,23 +806,11 @@ class ConnectionHandler(object):
             try:
                 response = sasl_cli.process(challenge=challenge)
             except puresasl.SASLError as err:
-                six.reraise(
-                    SASLException,
-                    SASLException("library error: %s" % err),
-                    sys.exc_info()[2],
-                )
-            except puresasl.SASLProtocolException as err:
-                six.reraise(
-                    AuthFailedError,
-                    AuthFailedError("protocol error: %s" % err),
-                    sys.exc_info()[2],
-                )
-            except Exception as err:
-                six.reraise(
-                    AuthFailedError,
-                    AuthFailedError("Unknown error: %s" % err),
-                    sys.exc_info()[2],
-                )
+                raise SASLException("library error") from err
+            except puresasl.SASLProtocolException as exc:
+                raise AuthFailedError("protocol error") from exc
+            except Exception as exc:
+                raise AuthFailedError("Unknown error") from exc
 
             if sasl_cli.complete and not response:
                 break
@@ -838,13 +824,9 @@ class ConnectionHandler(object):
 
             try:
                 header, buffer, offset = self._read_header(timeout)
-            except ConnectionDropped:
+            except ConnectionDropped as exc:
                 # Zookeeper simply drops connections with failed authentication
-                six.reraise(
-                    AuthFailedError,
-                    AuthFailedError("Connection dropped in SASL"),
-                    sys.exc_info()[2],
-                )
+                raise AuthFailedError("Connection dropped in SASL") from exc
 
             if header.xid != xid:
                 raise RuntimeError(
diff --git a/kazoo/protocol/serialization.py b/kazoo/protocol/serialization.py
index c702318..40e6360 100644
--- a/kazoo/protocol/serialization.py
+++ b/kazoo/protocol/serialization.py
@@ -2,8 +2,6 @@
 from collections import namedtuple
 import struct
 
-import six
-
 from kazoo.exceptions import EXCEPTIONS
 from kazoo.protocol.states import ZnodeStat
 from kazoo.security import ACL
@@ -367,7 +365,7 @@ class Transaction(namedtuple("Transaction", "operations")):
     def unchroot(client, response):
         resp = []
         for result in response:
-            if isinstance(result, six.string_types):
+            if isinstance(result, str):
                 resp.append(client.unchroot(result))
             else:
                 resp.append(result)
diff --git a/kazoo/python2atexit.py b/kazoo/python2atexit.py
deleted file mode 100644
index fdf78d2..0000000
--- a/kazoo/python2atexit.py
+++ /dev/null
@@ -1,71 +0,0 @@
-"""Uses the old atexit with added unregister for python 2.x
-and the new atexit for python 3.x
-"""
-import atexit
-import sys
-
-
-__all__ = ["register", "unregister"]
-
-
-_exithandlers = []
-
-
-def _run_exitfuncs():
-    """run any registered exit functions
-
-    _exithandlers is traversed in reverse order so functions are executed
-    last in, first out.
-    """
-
-    exc_info = None
-    while _exithandlers:
-        func, targs, kargs = _exithandlers.pop()
-        try:
-            func(*targs, **kargs)
-        except SystemExit:
-            exc_info = sys.exc_info()
-        except:  # noqa
-            import traceback
-
-            sys.stderr.write("Error in atexit._run_exitfuncs:\n")
-            traceback.print_exc()
-            exc_info = sys.exc_info()
-
-    if exc_info is not None:
-        raise exc_info[0](exc_info[1])
-
-
-def register(func, *targs, **kargs):
-    """register a function to be executed upon normal program termination
-
-    func - function to be called at exit
-    targs - optional arguments to pass to func
-    kargs - optional keyword arguments to pass to func
-
-    func is returned to facilitate usage as a decorator.
-    """
-    if hasattr(atexit, "unregister"):
-        atexit.register(func, *targs, **kargs)
-    else:
-        _exithandlers.append((func, targs, kargs))
-    return func
-
-
-def unregister(func):
-    """remove func from the list of functions that are registered
-    doesn't do anything if func is not found
-
-    func = function to be unregistered
-    """
-    if hasattr(atexit, "unregister"):
-        atexit.unregister(func)
-    else:
-        handler_entries = [e for e in _exithandlers if e[0] == func]
-        for e in handler_entries:
-            _exithandlers.remove(e)
-
-
-if not hasattr(atexit, "unregister"):
-    # Only in python 2.x
-    atexit.register(_run_exitfuncs)
diff --git a/kazoo/recipe/lock.py b/kazoo/recipe/lock.py
index 8959964..59c6d8f 100644
--- a/kazoo/recipe/lock.py
+++ b/kazoo/recipe/lock.py
@@ -15,16 +15,9 @@ and/or the lease has been lost.
 
 """
 import re
-import sys
-
-try:
-    from time import monotonic as now
-except ImportError:
-    from time import time as now
+import time
 import uuid
 
-import six
-
 from kazoo.exceptions import (
     CancelledError,
     KazooException,
@@ -45,13 +38,13 @@ class _Watch(object):
         self.started_at = None
 
     def start(self):
-        self.started_at = now()
+        self.started_at = time.monotonic()
 
     def leftover(self):
         if self.duration is None:
             return None
         else:
-            elapsed = now() - self.started_at
+            elapsed = time.monotonic() - self.started_at
             return max(0, self.duration - elapsed)
 
 
@@ -199,11 +192,10 @@ class Lock(object):
                 pass
             except KazooException:
                 # if we did ultimately fail, attempt to clean up
-                exc_info = sys.exc_info()
                 if not already_acquired:
                     self._best_effort_cleanup()
                     self.cancelled = False
-                six.reraise(exc_info[0], exc_info[1], exc_info[2])
+                raise
             if gotten:
                 self.is_acquired = gotten
             if not gotten and not already_acquired:
diff --git a/kazoo/testing/harness.py b/kazoo/testing/harness.py
index fa4427f..2d28a5b 100644
--- a/kazoo/testing/harness.py
+++ b/kazoo/testing/harness.py
@@ -1,10 +1,10 @@
 """Kazoo testing harnesses"""
+import atexit
 import logging
 import os
 import uuid
 import unittest
 
-from kazoo import python2atexit as atexit
 from kazoo.client import KazooClient
 from kazoo.exceptions import KazooException
 from kazoo.protocol.connection import _CONNECTION_DROP, _SESSION_EXPIRED
diff --git a/kazoo/tests/conftest.py b/kazoo/tests/conftest.py
index c7a4cc6..eef9965 100644
--- a/kazoo/tests/conftest.py
+++ b/kazoo/tests/conftest.py
@@ -4,7 +4,8 @@ log = logging.getLogger(__name__)
 
 
 def pytest_exception_interact(node, call, report):
-    cluster = node._testcase.cluster
-    log.error("Zookeeper cluster logs:")
-    for logs in cluster.get_logs():
-        log.error(logs)
+    if hasattr(node._testcase, "cluster"):
+        cluster = node._testcase.cluster
+        log.error("Zookeeper cluster logs:")
+        for logs in cluster.get_logs():
+            log.error(logs)
diff --git a/setup.cfg b/setup.cfg
index 12421b7..562e3a7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -39,9 +39,6 @@ project_urls =
 zip_safe = false
 include_package_data = true
 packages = find:
-install_requires =
-    six
-    selectors2>=2.0.2 ; python_version < "3.4.0"
 
 [aliases]
 release = sdist bdist_wheel