Remove six.PY3/six.PY2

The Python 2.7 Support has been removed by:
https://review.opendev.org/#/c/704096/
So remove hacking rules for compatibility between python 2 and 3

Change-Id: I0e78b982b79674520c7695c0cca7352677d7b7a0
diff --git a/tempest/api/compute/servers/test_novnc.py b/tempest/api/compute/servers/test_novnc.py
index 7931ca9..6ebdbdb 100644
--- a/tempest/api/compute/servers/test_novnc.py
+++ b/tempest/api/compute/servers/test_novnc.py
@@ -26,11 +26,6 @@
 
 CONF = config.CONF
 
-if six.PY2:
-    ord_func = ord
-else:
-    ord_func = int
-
 
 class NoVNCConsoleTestJSON(base.BaseV2ComputeTest):
     """Test novnc console"""
@@ -116,14 +111,14 @@
             # single word(4 bytes).
             self.assertEqual(
                 data_length, 4, 'Expected authentication type None.')
-            self.assertIn(1, [ord_func(data[i]) for i in (0, 3)],
+            self.assertIn(1, [int(data[i]) for i in (0, 3)],
                           'Expected authentication type None.')
         else:
             self.assertGreaterEqual(
                 len(data), 2, 'Expected authentication type None.')
             self.assertIn(
                 1,
-                [ord_func(data[i + 1]) for i in range(ord_func(data[0]))],
+                [int(data[i + 1]) for i in range(int(data[0]))],
                 'Expected authentication type None.')
             # Send to the server that we only support authentication
             # type None
@@ -136,7 +131,7 @@
                 len(data), 4,
                 'Server did not think security was successful.')
             self.assertEqual(
-                [ord_func(i) for i in data], [0, 0, 0, 0],
+                [int(i) for i in data], [0, 0, 0, 0],
                 'Server did not think security was successful.')
 
         # Say to leave the desktop as shared as part of client initialization
diff --git a/tempest/cmd/run.py b/tempest/cmd/run.py
index d82b6df..8bebce2 100644
--- a/tempest/cmd/run.py
+++ b/tempest/cmd/run.py
@@ -129,7 +129,6 @@
 
 from cliff import command
 from oslo_serialization import jsonutils as json
-import six
 from stestr import commands
 
 from tempest import clients
@@ -139,10 +138,6 @@
 from tempest.common import credentials_factory as credentials
 from tempest import config
 
-if six.PY2:
-    # Python 2 has not FileNotFoundError exception
-    FileNotFoundError = IOError
-
 CONF = config.CONF
 SAVED_STATE_JSON = "saved_state.json"
 
@@ -167,7 +162,7 @@
         # environment variable and fall back to "python", under python3
         # if it does not exist. we should set it to the python3 executable
         # to deal with this situation better for now.
-        if six.PY3 and 'PYTHON' not in os.environ:
+        if 'PYTHON' not in os.environ:
             os.environ['PYTHON'] = sys.executable
 
     def _create_stestr_conf(self):
diff --git a/tempest/common/compute.py b/tempest/common/compute.py
index edb9d16..45f6f6f 100644
--- a/tempest/common/compute.py
+++ b/tempest/common/compute.py
@@ -19,7 +19,6 @@
 import struct
 import textwrap
 
-import six
 from six.moves.urllib import parse as urlparse
 
 from oslo_log import log as logging
@@ -31,11 +30,6 @@
 from tempest.lib.common import rest_client
 from tempest.lib.common.utils import data_utils
 
-if six.PY2:
-    ord_func = ord
-else:
-    ord_func = int
-
 CONF = config.CONF
 
 LOG = logging.getLogger(__name__)
@@ -365,8 +359,8 @@
             # frames less than 125 bytes here (for the negotiation) and
             # that only the 2nd byte contains the length, and since the
             # server doesn't do masking, we can just read the data length
-            if ord_func(header[1]) & 127 > 0:
-                return self._recv(ord_func(header[1]) & 127)
+            if int(header[1]) & 127 > 0:
+                return self._recv(int(header[1]) & 127)
 
     def send_frame(self, data):
         """Wrapper for sending data to add in the WebSocket frame format."""
@@ -383,7 +377,7 @@
             frame_bytes.append(mask[i])
         # Mask each of the actual data bytes that we are going to send
         for i in range(len(data)):
-            frame_bytes.append(ord_func(data[i]) ^ mask[i % 4])
+            frame_bytes.append(int(data[i]) ^ mask[i % 4])
         # Convert our integer list to a binary array of bytes
         frame_bytes = struct.pack('!%iB' % len(frame_bytes), * frame_bytes)
         self._socket.sendall(frame_bytes)
diff --git a/tempest/lib/cli/base.py b/tempest/lib/cli/base.py
index d8c776b..c661d21 100644
--- a/tempest/lib/cli/base.py
+++ b/tempest/lib/cli/base.py
@@ -18,7 +18,6 @@
 import subprocess
 
 from oslo_log import log as logging
-import six
 
 from tempest.lib import base
 import tempest.lib.cli.output_parser
@@ -55,8 +54,6 @@
                     flags, action, params])
     cmd = cmd.strip()
     LOG.info("running: '%s'", cmd)
-    if six.PY2:
-        cmd = cmd.encode('utf-8')
     cmd = shlex.split(cmd)
     stdout = subprocess.PIPE
     stderr = subprocess.STDOUT if merge_stderr else subprocess.PIPE
@@ -67,10 +64,7 @@
                                        cmd,
                                        result,
                                        result_err)
-    if six.PY2:
-        return result
-    else:
-        return os.fsdecode(result)
+    return os.fsdecode(result)
 
 
 class CLIClient(object):
diff --git a/tempest/lib/common/thread.py b/tempest/lib/common/thread.py
index b47d40d..ef0ec73 100644
--- a/tempest/lib/common/thread.py
+++ b/tempest/lib/common/thread.py
@@ -13,13 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import six
-
-if six.PY2:
-    # module thread is removed in Python 3
-    from thread import get_ident  # noqa: H237,F401
-
-else:
-    # On Python3 thread module has been deprecated and get_ident has been moved
-    # to threading module
-    from threading import get_ident  # noqa: F401
+# On Python3 thread module has been deprecated and get_ident has been moved
+# to threading module
+from threading import get_ident  # noqa: F401
diff --git a/tempest/tests/cmd/test_run.py b/tempest/tests/cmd/test_run.py
index 5d9ddfa..3c99bbe 100644
--- a/tempest/tests/cmd/test_run.py
+++ b/tempest/tests/cmd/test_run.py
@@ -29,10 +29,6 @@
 from tempest.lib.common.utils import data_utils
 from tempest.tests import base
 
-if six.PY2:
-    # Python 2 has not FileNotFoundError exception
-    FileNotFoundError = IOError
-
 DEVNULL = open(os.devnull, 'wb')
 atexit.register(DEVNULL.close)
 
@@ -149,8 +145,7 @@
         ]
         # NOTE(mtreinish): on python 3 the subprocess prints b'' around
         # stdout.
-        if six.PY3:
-            result = ["b\'" + x + "\'" for x in result]
+        result = ["b\'" + x + "\'" for x in result]
         self.assertEqual(result, tests)
 
     def test_tempest_run_with_worker_file(self):