Remove some remnants of Python2 (#1172)

Co-authored-by: vgali7 <vgali7@gatech.edu>

Author: Lorak-mmk

.gitignore

@@ -42,3 +42,6 @@ tests/unit/cython/bytesio_testhelper.c
 #iPython
 *.ipynb
 
+venv
+docs/venv
+.eggs

CONTRIBUTING.rst

@@ -26,7 +26,6 @@ To protect the community, all contributors are required to `sign the DataStax Co
 
 Design and Implementation Guidelines
 ------------------------------------
-- We support Python 2.7+, so any changes must work in any of these runtimes (we use ``six``, ``futures``, and some internal backports for compatability)
 - We have integrations (notably Cassandra cqlsh) that require pure Python and minimal external dependencies. We try to avoid new external dependencies. Where compiled extensions are concerned, there should always be a pure Python fallback implementation.
 - This project follows `semantic versioning <http://semver.org/>`_, so breaking API changes will only be introduced in major versions.
 - Legacy ``cqlengine`` has varying degrees of overreaching client-side validation. Going forward, we will avoid client validation where server feedback is adequate and not overly expensive.

appveyor.yml

@@ -1,9 +1,6 @@
 environment:
   matrix:
-    - PYTHON: "C:\\Python27-x64"
-      cassandra_version: 3.11.2
-      ci_type: standard
-    - PYTHON: "C:\\Python35-x64"
+    - PYTHON: "C:\\Python37-x64"
       cassandra_version: 3.11.2
       ci_type: standard
 os: Visual Studio 2015

benchmarks/callback_full_pipeline.py

@@ -18,7 +18,6 @@
 from threading import Event
 
 from base import benchmark, BenchmarkThread
-from six.moves import range
 
 log = logging.getLogger(__name__)
 

benchmarks/future_batches.py

@@ -14,7 +14,7 @@
 
 import logging
 from base import benchmark, BenchmarkThread
-from six.moves import queue
+import queue
 
 log = logging.getLogger(__name__)
 

benchmarks/future_full_pipeline.py

@@ -14,7 +14,7 @@
 
 import logging
 from base import benchmark, BenchmarkThread
-from six.moves import queue
+import queue
 
 log = logging.getLogger(__name__)
 

benchmarks/sync.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 from base import benchmark, BenchmarkThread
-from six.moves import range
 
 
 class Runner(BenchmarkThread):

cassandra/auth.py

@@ -32,8 +32,6 @@
 except ImportError:
     SASLClient = None
 
-import six
-
 log = logging.getLogger(__name__)
 
 # Custom payload keys related to DSE Unified Auth
@@ -270,15 +268,15 @@ def __init__(self, username, password):
         self.password = password
 
     def get_mechanism(self):
-        return six.b("PLAIN")
+        return b"PLAIN"
 
     def get_initial_challenge(self):
-        return six.b("PLAIN-START")
+        return b"PLAIN-START"
 
     def evaluate_challenge(self, challenge):
-        if challenge == six.b('PLAIN-START'):
+        if challenge == b'PLAIN-START':
             data = "\x00%s\x00%s" % (self.username, self.password)
-            return data if six.PY2 else data.encode()
+            return data.encode()
         raise Exception('Did not receive a valid challenge response from server')
 
 
@@ -297,13 +295,13 @@ def __init__(self, host, service, qops, properties):
         self.sasl = SASLClient(host, service, 'GSSAPI', qops=qops, **properties)
 
     def get_mechanism(self):
-        return six.b("GSSAPI")
+        return b"GSSAPI"
 
     def get_initial_challenge(self):
-        return six.b("GSSAPI-START")
+        return b"GSSAPI-START"
 
     def evaluate_challenge(self, challenge):
-        if challenge == six.b('GSSAPI-START'):
+        if challenge == b'GSSAPI-START':
             return self.sasl.process()
         else:
             return self.sasl.process(challenge)

cassandra/cluster.py

@@ -21,6 +21,7 @@
 import atexit
 from binascii import hexlify
 from collections import defaultdict
+from collections.abc import Mapping
 from concurrent.futures import ThreadPoolExecutor, FIRST_COMPLETED, wait as wait_futures
 from copy import copy
 from functools import partial, wraps
@@ -29,8 +30,8 @@
 import logging
 from warnings import warn
 from random import random
-import six
-from six.moves import filter, range, queue as Queue
+import re
+import queue
 import socket
 import sys
 import time
@@ -79,7 +80,6 @@
                              HostTargetingStatement)
 from cassandra.marshal import int64_pack
 from cassandra.timestamps import MonotonicTimestampGenerator
-from cassandra.compat import Mapping
 from cassandra.util import _resolve_contact_points_to_string_map, Version
 
 from cassandra.datastax.insights.reporter import MonitorReporter
@@ -111,9 +111,6 @@
 except ImportError:
     from cassandra.util import WeakSet  # NOQA
 
-if six.PY3:
-    long = int
-
 def _is_eventlet_monkey_patched():
     if 'eventlet.patcher' not in sys.modules:
         return False
@@ -1158,7 +1155,7 @@ def __init__(self,
             else:
                 self._contact_points_explicit = True
 
-            if isinstance(contact_points, six.string_types):
+            if isinstance(contact_points, str):
                 raise TypeError("contact_points should not be a string, it should be a sequence (e.g. list) of strings")
 
             if None in contact_points:
@@ -1793,8 +1790,8 @@ def _new_session(self, keyspace):
         return session
 
     def _session_register_user_types(self, session):
-        for keyspace, type_map in six.iteritems(self._user_types):
-            for udt_name, klass in six.iteritems(type_map):
+        for keyspace, type_map in self._user_types.items():
+            for udt_name, klass in type_map.items():
                 session.user_type_registered(keyspace, udt_name, klass)
 
     def _cleanup_failed_on_up_handling(self, host):
@@ -2683,7 +2680,7 @@ def execute_async(self, query, parameters=None, trace=False, custom_payload=None
         """
         custom_payload = custom_payload if custom_payload else {}
         if execute_as:
-            custom_payload[_proxy_execute_key] = six.b(execute_as)
+            custom_payload[_proxy_execute_key] = execute_as.encode()
 
         future = self._create_response_future(
             query, parameters, trace, custom_payload, timeout,
@@ -2747,8 +2744,8 @@ def execute_graph_async(self, query, parameters=None, trace=False, execution_pro
 
         custom_payload = execution_profile.graph_options.get_options_map()
         if execute_as:
-            custom_payload[_proxy_execute_key] = six.b(execute_as)
-        custom_payload[_request_timeout_key] = int64_pack(long(execution_profile.request_timeout * 1000))
+            custom_payload[_proxy_execute_key] = execute_as.encode()
+        custom_payload[_request_timeout_key] = int64_pack(int(execution_profile.request_timeout * 1000))
 
         future = self._create_response_future(query, parameters=None, trace=trace, custom_payload=custom_payload,
                                               timeout=_NOT_SET, execution_profile=execution_profile)
@@ -2885,7 +2882,7 @@ def _create_response_future(self, query, parameters, trace, custom_payload,
 
         prepared_statement = None
 
-        if isinstance(query, six.string_types):
+        if isinstance(query, str):
             query = SimpleStatement(query)
         elif isinstance(query, PreparedStatement):
             query = query.bind(parameters)
@@ -3353,10 +3350,6 @@ def user_type_registered(self, keyspace, user_type, klass):
                 'User type %s does not exist in keyspace %s' % (user_type, keyspace))
 
         field_names = type_meta.field_names
-        if six.PY2:
-            # go from unicode to string to avoid decode errors from implicit
-            # decode when formatting non-ascii values
-            field_names = [fn.encode('utf-8') for fn in field_names]
 
         def encode(val):
             return '{ %s }' % ' , '.join('%s : %s' % (
@@ -4035,7 +4028,7 @@ def _get_schema_mismatches(self, peers_result, local_result, local_address):
             log.debug("[control connection] Schemas match")
             return None
 
-        return dict((version, list(nodes)) for version, nodes in six.iteritems(versions))
+        return dict((version, list(nodes)) for version, nodes in versions.items())
 
     def _get_peers_query(self, peers_query_type, connection=None):
         """
@@ -4155,7 +4148,7 @@ class _Scheduler(Thread):
     is_shutdown = False
 
     def __init__(self, executor):
-        self._queue = Queue.PriorityQueue()
+        self._queue = queue.PriorityQueue()
         self._scheduled_tasks = set()
         self._count = count()
         self._executor = executor
@@ -4213,7 +4206,7 @@ def run(self):
                     else:
                         self._queue.put_nowait((run_at, i, task))
                         break
-            except Queue.Empty:
+            except queue.Empty:
                 pass
 
             time.sleep(0.1)