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.

pep8 errors are fixed by
 $ autopep8 --select=E127,E128,E501 --max-line-length 79 -r \
    --in-place os_api_ref

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

Change-Id: I482aa3eb40d7c8cefaba9ea9df5b9d1dcd3827c1

.pre-commit-config.yaml

@@ -23,3 +23,8 @@ repos:
     hooks:
       - id: hacking
         additional_dependencies: []
+  - repo: https://github.com/asottile/pyupgrade
+    rev: v3.18.0
+    hooks:
+      - id: pyupgrade
+        args: [--py3-only]

os_api_ref/__init__.py

@@ -86,7 +86,7 @@ def ordered_load(
     # numbers) as strings. So that microversion specification of 2.20
     # and 2.2 don't get confused.
     OrderedLoader.add_constructor(
-        u'tag:yaml.org,2002:float',
+        'tag:yaml.org,2002:float',
         yaml.constructor.SafeConstructor.construct_yaml_str)
 
     return yaml.load(stream, OrderedLoader)
@@ -198,7 +198,7 @@ class RestMethodDirective(rst.Directive):
         # they are still unlikely to occurr and it is way shorter
         # than stronger SHAs.
         node_hash = hashlib.sha1(str(node).encode('utf-8')).hexdigest()
-        temp_target = "%s-%s-selector" % (node['target'], node_hash)
+        temp_target = "{}-{}-selector".format(node['target'], node_hash)
         target = nodes.target(ids=[temp_target])
         self.state.add_target(temp_target, '', target, lineno)
         section += node
@@ -222,9 +222,9 @@ class RestParametersDirective(Table):
 
         lookup = {}
         try:
-            with open(fpath, 'r') as stream:
+            with open(fpath) as stream:
                 lookup = ordered_load(stream)
-        except IOError:
+        except OSError:
             LOG.warning("Parameters file not found, %s", fpath,
                         location=(self.env.docname, None))
             return
@@ -595,10 +595,10 @@ Microversions
 def build_mv_item(major, micro, releases):
     version = "%d.%d" % (major, micro)
     if version in releases:
-        return '<option value="%s">%s - %s</option>' % (
+        return '<option value="{}">{} - {}</option>'.format(
             version, version, releases[version].capitalize())
     else:
-        return '<option value="%s">%s</option>' % (version, version)
+        return '<option value="{}">{}</option>'.format(version, version)
 
 
 def resolve_rest_references(app, doctree):

os_api_ref/http_codes.py

@@ -41,7 +41,7 @@ class HTTPResponseCodeDirective(Table):
 
     def __init__(self, *args, **kwargs):
         self.CODES.update(responses)
-        super(HTTPResponseCodeDirective, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def _load_status_file(self, fpath):
         global HTTP_YAML_CACHE
@@ -50,9 +50,9 @@ class HTTPResponseCodeDirective(Table):
 
         # LOG.info("Fpath: %s" % fpath)
         try:
-            with open(fpath, 'r') as stream:
+            with open(fpath) as stream:
                 lookup = yaml.safe_load(stream)
-        except IOError:
+        except OSError:
             LOG.warning(
                 "Parameters file %s not found" % fpath,
                 (self.env.docname, None))
@@ -92,7 +92,8 @@ class HTTPResponseCodeDirective(Table):
 
         if status_type not in self.status_types:
             error = self.state_machine.reporter.error(
-                'Type %s is not one of %s' % (status_type, self.status_types),
+                'Type {} is not one of {}'.format(
+                    status_type, self.status_types),
                 nodes.literal_block(self.block_text, self.block_text),
                 line=self.lineno)
             return [error]
@@ -142,7 +143,7 @@ class HTTPResponseCodeDirective(Table):
                         )
                 except KeyError:
                     LOG.warning(
-                        "Could not find %s for code %s" % (reason, code))
+                        "Could not find {} for code {}".format(reason, code))
                     new_content.append(
                         (code, self.status_defs[code]['default']))
 

os_api_ref/tests/base.py

@@ -62,7 +62,7 @@ class OutputStreamCapture(fixtures.Fixture):
     tests.
     """
     def setUp(self):
-        super(OutputStreamCapture, self).setUp()
+        super().setUp()
         if os.environ.get('OS_STDOUT_CAPTURE') in _TRUE_VALUES:
             self.out = self.useFixture(fixtures.StringStream('stdout'))
             self.useFixture(
@@ -93,7 +93,7 @@ class Timeout(fixtures.Fixture):
     """
 
     def __init__(self, timeout, scaling=1):
-        super(Timeout, self).__init__()
+        super().__init__()
         try:
             self.test_timeout = int(timeout)
         except ValueError:
@@ -105,7 +105,7 @@ class Timeout(fixtures.Fixture):
             raise ValueError('scaling value must be >= 1')
 
     def setUp(self):
-        super(Timeout, self).setUp()
+        super().setUp()
         if self.test_timeout > 0:
             self.useFixture(fixtures.Timeout(self.test_timeout, gentle=True))
 
@@ -116,7 +116,7 @@ class TestCase(testtools.TestCase):
 
     def setUp(self):
         """Run before each test method to initialize test environment."""
-        super(TestCase, self).setUp()
+        super().setUp()
         self.useFixture(Timeout(
             os.environ.get('OS_TEST_TIMEOUT', 0)))
         self.useFixture(OutputStreamCapture())

os_api_ref/tests/test_basic_example.py

@@ -31,7 +31,7 @@ class TestBasicExample(base.TestCase):
 
     @base.with_app(buildername='html', srcdir=base.example_dir('basic'))
     def setUp(self, app, status, warning):
-        super(TestBasicExample, self).setUp()
+        super().setUp()
         self.app = app
         self.status = status
         self.warning = warning

os_api_ref/tests/test_microversions.py

@@ -32,7 +32,7 @@ class TestMicroversions(base.TestCase):
     @base.with_app(buildername='html',
                    srcdir=base.example_dir('microversions'))
     def setUp(self, app, status, warning):
-        super(TestMicroversions, self).setUp()
+        super().setUp()
         self.app = app
         self.app.build()
         self.status = status.getvalue()

os_api_ref/tests/test_warnings.py

@@ -33,7 +33,7 @@ class TestWarnings(base.TestCase):
 
     @base.with_app(buildername='html', srcdir=base.example_dir('warnings'))
     def setUp(self, app, status, warning):
-        super(TestWarnings, self).setUp()
+        super().setUp()
         self.app = app
         self.app.build()
         self.status = status.getvalue()