Remove support for end-of-life Python 2.7 (#1318)

Remove support for end-of-life Python 2.7

Python 2.7 is end of life. It is no longer receiving bug fixes,
including for security issues. Python 2.7 went EOL on 2020-01-01. For
additional details on support Python versions, see:

Supported: https://devguide.python.org/#status-of-python-branches
EOL: https://devguide.python.org/devcycle/#end-of-life-branches

Removing support for EOL Pythons will reduce testing and maintenance
resources while allowing the library to move towards a modern Python 3
style. Python 2.7 users can continue to use the previous version of
redis-py.

Was able to simplify the code:

- Removed redis._compat module
- Removed __future__ imports
- Removed object from class definition (all classes are new style)
- Removed long (Python 3 unified numeric types)
- Removed deprecated __nonzero__ method
- Use simpler Python 3 super() syntax
- Use unified OSError exception
- Use yield from syntax

Co-authored-by: Andy McCurdy <andy@andymccurdy.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/redis/lock.py b/redis/lock.py
index 5c47748..e51f169 100644
--- a/redis/lock.py
+++ b/redis/lock.py
@@ -1,11 +1,11 @@
 import threading
 import time as mod_time
 import uuid
+from types import SimpleNamespace
 from redis.exceptions import LockError, LockNotOwnedError
-from redis.utils import dummy
 
 
-class Lock(object):
+class Lock:
     """
     A shared, distributed Lock. Using Redis for locking allows the Lock
     to be shared across processes and/or machines.
@@ -129,7 +129,11 @@ class Lock(object):
         self.blocking = blocking
         self.blocking_timeout = blocking_timeout
         self.thread_local = bool(thread_local)
-        self.local = threading.local() if self.thread_local else dummy()
+        self.local = (
+            threading.local()
+            if self.thread_local
+            else SimpleNamespace()
+        )
         self.local.token = None
         self.register_scripts()