Stop using six library

Since we've dropped support for Python 2.7, it's time to look at
the bright future that Python 3.x will bring and stop forcing
compatibility with older versions.
This patch removes the six library from requirements, not
looking back.

Change-Id: I4bf885bc7d1ccdf46dde3e0b10a8dbec304aaf9b

ironic_lib/disk_utils.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import gzip
+import io
 import logging
 import math
 import os
@@ -31,7 +32,6 @@ from oslo_utils import excutils
 from oslo_utils import imageutils
 from oslo_utils import units
 import requests
-import six
 
 from ironic_lib.common.i18n import _
 from ironic_lib import disk_partitioner
@@ -519,7 +519,7 @@ def _get_configdrive(configdrive, node_uuid, tempdir=None):
         data = configdrive
 
     try:
-        data = six.BytesIO(base64.decode_as_bytes(data))
+        data = io.BytesIO(base64.decode_as_bytes(data))
     except TypeError:
         error_msg = (_('Config drive for node %s is not base64 encoded '
                        'or the content is malformed.') % node_uuid)

ironic_lib/exception.py

@@ -28,7 +28,6 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from oslo_utils import excutils
-import six
 
 from ironic_lib.common.i18n import _
 
@@ -68,7 +67,7 @@ def _ensure_exception_kwargs_serializable(exc_class_name, kwargs):
     :returns: a dictionary of serializable keyword arguments.
     """
     serializers = [(jsonutils.dumps, _('when converting to JSON')),
-                   (six.text_type, _('when converting to string'))]
+                   (str, _('when converting to string'))]
     exceptions = collections.defaultdict(list)
     serializable_kwargs = {}
     for k, v in kwargs.items():
@@ -108,7 +107,7 @@ class IronicException(Exception):
     with the keyword arguments provided to the constructor.
 
     If you need to access the message from an exception you should use
-    six.text_type(exc)
+    str(exc)
 
     """
 
@@ -148,25 +147,6 @@ class IronicException(Exception):
 
         super(IronicException, self).__init__(message)
 
-    def __str__(self):
-        """Encode to utf-8 then wsme api can consume it as well."""
-        value = self.__unicode__()
-        if six.PY3:
-            # On Python 3 unicode is the same as str
-            return value
-        else:
-            return value.encode('utf-8')
-
-    def __unicode__(self):
-        """Return a unicode representation of the exception message."""
-        return six.text_type(self.args[0])
-
-    def format_message(self):
-        if self.__class__.__name__.endswith('_Remote'):
-            return self.args[0]
-        else:
-            return six.text_type(self)
-
 
 class InstanceDeployFailure(IronicException):
     _msg_fmt = _("Failed to deploy instance: %(reason)s")

ironic_lib/mdns.py

@@ -20,11 +20,11 @@ import collections
 import ipaddress
 import socket
 import time
+from urllib import parse as urlparse
 
 from oslo_config import cfg
 from oslo_config import types as cfg_types
 from oslo_log import log as logging
-from six.moves.urllib import parse
 import zeroconf
 
 from ironic_lib.common.i18n import _
@@ -261,7 +261,7 @@ def get_endpoint(service_type):
 
 def _parse_endpoint(endpoint, service_type=None):
     params = {}
-    url = parse.urlparse(endpoint)
+    url = urlparse.urlparse(endpoint)
     port = url.port
 
     if port is None:

ironic_lib/metrics.py

@@ -14,11 +14,10 @@
 #    under the License.
 
 import abc
+import functools
 import random
 import time
 
-import six
-
 from ironic_lib.common.i18n import _
 
 
@@ -46,7 +45,7 @@ class Timer(object):
         :param metrics: The metric logger
         :param name: The metric name
         """
-        if not isinstance(name, six.string_types):
+        if not isinstance(name, str):
             raise TypeError(_("The metric name is expected to be a string. "
                             "Value is %s") % name)
         self.metrics = metrics
@@ -54,7 +53,7 @@ class Timer(object):
         self._start = None
 
     def __call__(self, f):
-        @six.wraps(f)
+        @functools.wraps(f)
         def wrapped(*args, **kwargs):
             start = _time()
             result = f(*args, **kwargs)
@@ -101,7 +100,7 @@ class Counter(object):
         :param name: The metric name
         :param sample_rate: Probabilistic rate at which the values will be sent
         """
-        if not isinstance(name, six.string_types):
+        if not isinstance(name, str):
             raise TypeError(_("The metric name is expected to be a string. "
                             "Value is %s") % name)
 
@@ -116,7 +115,7 @@ class Counter(object):
         self.sample_rate = sample_rate
 
     def __call__(self, f):
-        @six.wraps(f)
+        @functools.wraps(f)
         def wrapped(*args, **kwargs):
             self.metrics.send_counter(
                 self.metrics.get_metric_name(self.name),
@@ -156,14 +155,14 @@ class Gauge(object):
         :param metrics: The metric logger
         :param name: The metric name
         """
-        if not isinstance(name, six.string_types):
+        if not isinstance(name, str):
             raise TypeError(_("The metric name is expected to be a string. "
                             "Value is %s") % name)
         self.metrics = metrics
         self.name = name
 
     def __call__(self, f):
-        @six.wraps(f)
+        @functools.wraps(f)
         def wrapped(*args, **kwargs):
             result = f(*args, **kwargs)
             self.metrics.send_gauge(self.metrics.get_metric_name(self.name),
@@ -178,8 +177,7 @@ def _time():
     return time.time()
 
 
-@six.add_metaclass(abc.ABCMeta)
-class MetricLogger(object):
+class MetricLogger(object, metaclass=abc.ABCMeta):
     """Abstract class representing a metrics logger.
 
     A MetricLogger sends data to a backend (noop or statsd).

ironic_lib/metrics_utils.py

@@ -14,7 +14,6 @@
 #    under the License.
 
 from oslo_config import cfg
-import six
 
 from ironic_lib.common.i18n import _
 from ironic_lib import exception
@@ -62,7 +61,7 @@ def get_metrics_logger(prefix='', backend=None, host=None, delimiter='.'):
     :param delimiter: Delimiter to use for the metrics name.
     :return: The new MetricLogger.
     """
-    if not isinstance(prefix, six.string_types):
+    if not isinstance(prefix, str):
         msg = (_("This metric prefix (%s) is of unsupported type. "
                  "Value should be a string or None")
                % str(prefix))

ironic_lib/tests/test_exception.py

@@ -16,7 +16,6 @@ import re
 
 import mock
 from oslo_config import cfg
-import six
 
 from ironic_lib import exception
 from ironic_lib.tests import base
@@ -34,22 +33,9 @@ class TestException(exception.IronicException):
 
 
 class TestIronicException(base.IronicLibTestCase):
-    def test___str__encoding(self):
-        expected = b'\xc3\xa9\xe0\xaf\xb2\xe0\xbe\x84'
-        if six.PY3:
-            expected = expected.decode('utf-8')
-        message = six.unichr(233) + six.unichr(0x0bf2) + six.unichr(3972)
-        exc = exception.IronicException(message)
-        self.assertEqual(expected, exc.__str__())
-
-    def test___str__non_string(self):
-        exc = exception.IronicException(42)
-        self.assertEqual("42", exc.__str__())
-        self.assertEqual(u"42", exc.__unicode__())
-
     def test___init___json_serializable(self):
         exc = TestException(spam=[1, 2, 3], ham='eggs')
-        self.assertIn('[1, 2, 3]', six.text_type(exc))
+        self.assertIn('[1, 2, 3]', str(exc))
         self.assertEqual('[1, 2, 3]', exc.kwargs['spam'])
 
     def test___init___string_serializable(self):
@@ -57,7 +43,7 @@ class TestIronicException(base.IronicLibTestCase):
             spam=type('ni', (object,), dict(a=1, b=2))(), ham='eggs'
         )
         check_str = 'ni object at'
-        self.assertIn(check_str, six.text_type(exc))
+        self.assertIn(check_str, str(exc))
         self.assertIn(check_str, exc.kwargs['spam'])
 
     @mock.patch.object(exception.LOG, 'error', autospec=True)

ironic_lib/tests/test_metrics.py

@@ -49,24 +49,24 @@ class MockedMetricLogger(metricslib.MetricLogger):
 
 class TestMetricReflection(base.IronicLibTestCase):
     def test_timer_reflection(self):
-        # Ensure our decorator is done correctly (six.wraps) and we can get the
-        # arguments of our decorated function.
+        # Ensure our decorator is done correctly (functools.wraps) and we can
+        # get the arguments of our decorated function.
         expected = ['run', 'timer']
         signature = reflection.get_signature(timer_check)
         parameters = list(signature.parameters)
         self.assertEqual(expected, parameters)
 
     def test_counter_reflection(self):
-        # Ensure our decorator is done correctly (six.wraps) and we can get the
-        # arguments of our decorated function.
+        # Ensure our decorator is done correctly (functools.wraps) and we can
+        # get the arguments of our decorated function.
         expected = ['run', 'counter']
         signature = reflection.get_signature(counter_check)
         parameters = list(signature.parameters)
         self.assertEqual(expected, parameters)
 
     def test_gauge_reflection(self):
-        # Ensure our decorator is done correctly (six.wraps) and we can get the
-        # arguments of our decorated function.
+        # Ensure our decorator is done correctly (functools.wraps) and we can
+        # get the arguments of our decorated function.
         expected = ['run', 'gauge']
         signature = reflection.get_signature(gauge_check)
         parameters = list(signature.parameters)

ironic_lib/utils.py

@@ -24,6 +24,7 @@ import ipaddress
 import logging
 import os
 import re
+from urllib import parse as urlparse
 
 from oslo_concurrency import processutils
 from oslo_config import cfg
@@ -32,8 +33,6 @@ from oslo_utils import excutils
 from oslo_utils import specs_matcher
 from oslo_utils import strutils
 from oslo_utils import units
-import six
-from six.moves.urllib import parse
 
 from ironic_lib.common.i18n import _
 from ironic_lib import exception
@@ -195,7 +194,7 @@ def _extract_hint_operator_and_values(hint_expression, hint_name):
         :op: The operator. An empty string in case of None.
         :values: A list of values stripped and converted to lowercase.
     """
-    expression = six.text_type(hint_expression).strip().lower()
+    expression = str(hint_expression).strip().lower()
     if not expression:
         raise ValueError(
             _('Root device hint "%s" expression is empty') % hint_name)
@@ -228,7 +227,7 @@ def _normalize_hint_expression(hint_expression, hint_name):
     :returns: A normalized string.
     """
     hdict = _extract_hint_operator_and_values(hint_expression, hint_name)
-    result = hdict['op'].join([' %s ' % parse.quote(t)
+    result = hdict['op'].join([' %s ' % urlparse.quote(t)
                                for t in hdict['values']])
     return (hdict['op'] + result).strip()
 
@@ -249,7 +248,7 @@ def _append_operator_to_hints(root_device):
         if VALID_ROOT_DEVICE_HINTS[name] is bool:
             continue
 
-        expression = six.text_type(expression)
+        expression = str(expression)
         ast = ROOT_DEVICE_HINTS_GRAMMAR.parseString(expression)
         if len(ast) > 1:
             continue
@@ -290,7 +289,7 @@ def parse_root_device_hints(root_device):
     for name, expression in root_device.items():
         hint_type = VALID_ROOT_DEVICE_HINTS[name]
         if hint_type is str:
-            if not isinstance(expression, six.string_types):
+            if not isinstance(expression, str):
                 raise ValueError(
                     _('Root device hint "%(name)s" is not a string value. '
                       'Hint expression: %(expression)s') %
@@ -517,7 +516,7 @@ def get_route_source(dest, ignore_link_local=True):
 
     try:
         source = out.strip().split('\n')[0].split('src')[1].split()[0]
-        if (ipaddress.ip_address(six.u(source)).is_link_local
+        if (ipaddress.ip_address(source).is_link_local
                 and ignore_link_local):
             LOG.debug('Ignoring link-local source to %(dest)s: %(rec)s',
                       {'dest': dest, 'rec': out})

lower-constraints.txt

@@ -61,7 +61,6 @@ requestsexceptions==1.2.0
 restructuredtext-lint==1.1.1
 rfc3986==0.3.1
 Routes==2.3.1
-six==1.10.0
 snowballstemmer==1.2.1
 Sphinx==1.6.2
 sphinxcontrib-websupport==1.0.1

requirements.txt

@@ -10,6 +10,5 @@ oslo.serialization!=2.19.1,>=2.18.0 # Apache-2.0
 oslo.service!=1.28.1,>=1.24.0 # Apache-2.0
 oslo.utils>=3.33.0 # Apache-2.0
 requests>=2.14.2 # Apache-2.0
-six>=1.10.0 # MIT
 oslo.log>=3.36.0 # Apache-2.0
 zeroconf>=0.24.0;python_version>='3.0' # LGPL