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.

Change-Id: Iee7bdff54efe4bea1b255c1114a4291c3e62fea0

.pre-commit-config.yaml

@@ -24,3 +24,8 @@ repos:
       - id: hacking
         additional_dependencies: []
         exclude: '^(doc|releasenotes|tools)/.*$'
+  - repo: https://github.com/asottile/pyupgrade
+    rev: v3.18.0
+    hooks:
+      - id: pyupgrade
+        args: [--py3-only]

doc/source/conf.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #
 # etcd3-gateway documentation build configuration file, created by
 # sphinx-quickstart on Sat Mar 25 20:42:09 2017.

etcd3gw/__init__.py

@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 # Licensed under the Apache License, Version 2.0 (the "License"); you may
 # not use this file except in compliance with the License. You may obtain
 # a copy of the License at
@@ -12,7 +10,6 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from __future__ import absolute_import
 import pbr.version
 
 from etcd3gw.client import client

etcd3gw/client.py

@@ -41,7 +41,7 @@ _EXCEPTIONS_BY_CODE = {
 DEFAULT_API_PATH = os.getenv('ETCD3GW_API_PATH')
 
 
-class Etcd3Client(object):
+class Etcd3Client:
     def __init__(self, host='localhost', port=2379, protocol="http",
                  ca_cert=None, cert_key=None, cert_cert=None, timeout=None,
                  api_path=DEFAULT_API_PATH):

etcd3gw/exceptions.py

@@ -13,7 +13,7 @@
 
 class Etcd3Exception(Exception):
     def __init__(self, detail_text=None, *args):
-        super(Etcd3Exception, self).__init__(*args)
+        super().__init__(*args)
         self.detail_text = detail_text
 
 

etcd3gw/lease.py

@@ -13,7 +13,7 @@
 from etcd3gw.utils import _decode
 
 
-class Lease(object):
+class Lease:
     def __init__(self, id, client=None):
         """Lease object for expiring keys
 

etcd3gw/lock.py

@@ -17,7 +17,7 @@ from etcd3gw.utils import DEFAULT_TIMEOUT
 from etcd3gw.utils import LOCK_PREFIX
 
 
-class Lock(object):
+class Lock:
     def __init__(self, name, ttl=DEFAULT_TIMEOUT, client=None):
         """Create a lock using the given name with specified timeout
 

etcd3gw/tests/test_etcd3gw.py

@@ -360,7 +360,7 @@ class TestEtcd3Gateway(base.TestCase):
 
             self.assertEqual(
                 event['kv']['key'],
-                ('%s%s' % (key, change_count)).encode("latin-1"),
+                ('{}{}'.format(key, change_count)).encode("latin-1"),
             )
             self.assertEqual(
                 event['kv']['value'],

etcd3gw/watch.py

@@ -39,7 +39,7 @@ def _watch(resp, callback):
                 callback(event)
 
 
-class Watcher(object):
+class Watcher:
 
     KW_ARGS = ['start_revision', 'progress_notify', 'filters', 'prev_kv']
     KW_ENCODED_ARGS = ['range_end']

releasenotes/source/conf.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at