This file contains only the changes history before redis-py version 4.0.0
After redis-py version 4.0.0 all changes can be found and tracked in the Release notes pubished in GitHub

* 3.5.3 (June 1, 2020)
  * Restore try/except clauses to __del__ methods. These will be removed
      in 4.0 when more explicit resource management if enforced. #1339
  * Update the master_address when Sentinels promote a new master. #847
  * Update SentinelConnectionPool to not forcefully disconnect other in-use
      connections which can negatively affect threaded applications. #1345
* 3.5.2 (May 14, 2020)
  * Tune the locking in ConnectionPool.get_connection so that the lock is
      not held while waiting for the socket to establish and validate the
      TCP connection.
* 3.5.1 (May 9, 2020)
  * Fix for HSET argument validation to allow any non-None key. Thanks
      @AleksMat, #1337, #1341
* 3.5.0 (April 29, 2020)
  * Removed exception trapping from __del__ methods. redis-py objects that
      hold various resources implement __del__ cleanup methods to release
      those resources when the object goes out of scope. This provides a
      fallback for when these objects aren't explicitly closed by user code.
      Prior to this change any errors encountered in closing these resources
      would be hidden from the user. Thanks @jdufresne. #1281
  * Expanded support for connection strings specifying a username connecting
      to pre-v6 servers. #1274
  * Optimized Lock's blocking_timeout and sleep. If the lock cannot be
      acquired and the sleep value would cause the loop to sleep beyond
      blocking_timeout, fail immediately. Thanks @clslgrnc. #1263
  * Added support for passing Python memoryviews to Redis command args that
      expect strings or bytes. The memoryview instance is sent directly to
      the socket such that there are zero copies made of the underlying data
      during command packing. Thanks @Cody-G. #1265, #1285
  * HSET command now can accept multiple pairs. HMSET has been marked as
      deprecated now. Thanks to @laixintao #1271
  * Don't manually DISCARD when encountering an ExecAbortError.
      Thanks @nickgaya, #1300/#1301
  * Reset the watched state of pipelines after calling exec. This saves
      a roundtrip to the server by not having to call UNWATCH within
      Pipeline.reset(). Thanks @nickgaya, #1299/#1302
  * Added the KEEPTTL option for the SET command. Thanks
      @laixintao #1304/#1280
  * Added the MEMORY STATS command. #1268
  * Lock.extend() now has a new option, `replace_ttl`. When False (the
      default), Lock.extend() adds the `additional_time` to the lock's existing
      TTL. When replace_ttl=True, the lock's existing TTL is replaced with
      the value of `additional_time`.
  * Add testing and support for PyPy.
* 3.4.1
  * Move the username argument in the Redis and Connection classes to the
      end of the argument list. This helps those poor souls that specify all
      their connection options as non-keyword arguments. #1276
  * Prior to ACL support, redis-py ignored the username component of
      Connection URLs. With ACL support, usernames are no longer ignored and
      are used to authenticate against an ACL rule. Some cloud vendors with
      managed Redis instances (like Heroku) provide connection URLs with a
      username component pre-ACL that is not intended to be used. Sending that
      username to Redis servers < 6.0.0 results in an error. Attempt to detect
      this condition and retry the AUTH command with only the password such
      that authentication continues to work for these users. #1274
  * Removed the __eq__ hooks to Redis and ConnectionPool that were added
      in 3.4.0. This ended up being a bad idea as two separate connection
      pools be considered equal yet manage a completely separate set of
      connections.
* 3.4.0
  * Allow empty pipelines to be executed if there are WATCHed keys.
      This is a convenient way to test if any of the watched keys changed
      without actually running any other commands. Thanks @brianmaissy.
      #1233, #1234
  * Removed support for end of life Python 3.4.
  * Added support for all ACL commands in Redis 6. Thanks @IAmATeaPot418
      for helping.
  * Pipeline instances now always evaluate to True. Prior to this change,
      pipeline instances relied on __len__ for boolean evaluation which
      meant that pipelines with no commands on the stack would be considered
      False. #994
  * Client instances and Connection pools now support a 'client_name'
      argument. If supplied, all connections created will call CLIENT SETNAME
      as soon as the connection is opened. Thanks to @Habbie for supplying
      the basis of this change. #802
  * Added the 'ssl_check_hostname' argument to specify whether SSL
      connections should require the server hostname to match the hostname
      specified in the SSL cert. By default 'ssl_check_hostname' is False
      for backwards compatibility. #1196
  * Slightly optimized command packing. Thanks @Deneby67. #1255
  * Added support for the TYPE argument to SCAN. Thanks @netocp. #1220
  * Better thread and fork safety in ConnectionPool and
      BlockingConnectionPool. Added better locking to synchronize critical
      sections rather than relying on CPython-specific implementation details
      relating to atomic operations. Adjusted how the pools identify and
      deal with a fork. Added a ChildDeadlockedError exception that is
      raised by child processes in the very unlikely chance that a deadlock
      is encountered. Thanks @gmbnomis, @mdellweg, @yht804421715. #1270,
      #1138, #1178, #906, #1262
  * Added __eq__ hooks to the Redis and ConnectionPool classes.
      Thanks @brainix. #1240
* 3.3.11
  * Further fix for the SSLError -> TimeoutError mapping to work
      on obscure releases of Python 2.7.
* 3.3.10
  * Fixed a potential error handling bug for the SSLError -> TimeoutError
      mapping introduced in 3.3.9. Thanks @zbristow. #1224
* 3.3.9
  * Mapped Python 2.7 SSLError to TimeoutError where appropriate. Timeouts
      should now consistently raise TimeoutErrors on Python 2.7 for both
      unsecured and secured connections. Thanks @zbristow. #1222
* 3.3.8
  * Fixed MONITOR parsing to properly parse IPv6 client addresses, unix
      socket connections and commands issued from Lua. Thanks @kukey. #1201
* 3.3.7
  * Fixed a regression introduced in 3.3.0 where socket.error exceptions
      (or subclasses) could potentially be raised instead of
      redis.exceptions.ConnectionError. #1202
* 3.3.6
  * Fixed a regression in 3.3.5 that caused PubSub.get_message() to raise
      a socket.timeout exception when passing a timeout value. #1200
* 3.3.5
  * Fix an issue where socket.timeout errors could be handled by the wrong
      exception handler in Python 2.7.
* 3.3.4
  * More specifically identify nonblocking read errors for both SSL and
      non-SSL connections. 3.3.1, 3.3.2 and 3.3.3 on Python 2.7 could
      potentially mask a ConnectionError. #1197
* 3.3.3
  * The SSL module in Python < 2.7.9 handles non-blocking sockets
      differently than 2.7.9+. This patch accommodates older versions. #1197
* 3.3.2
  * Further fixed a regression introduced in 3.3.0 involving SSL and
      non-blocking sockets. #1197
* 3.3.1
  * Fixed a regression introduced in 3.3.0 involving SSL and non-blocking
      sockets. #1197
* 3.3.0
  * Resolve a race condition with the PubSubWorkerThread. #1150
  * Cleanup socket read error messages. Thanks Vic Yu. #1159
  * Cleanup the Connection's selector correctly. Thanks Bruce Merry. #1153
  * Added a Monitor object to make working with MONITOR output easy.
      Thanks Roey Prat #1033
  * Internal cleanup: Removed the legacy Token class which was necessary
      with older version of Python that are no longer supported. #1066
  * Response callbacks are now case insensitive. This allows users that
      call Redis.execute_command() directly to pass lower-case command
      names and still get reasonable responses. #1168
  * Added support for hiredis-py 1.0.0 encoding error support. This should
      make the PythonParser and the HiredisParser behave identically
      when encountering encoding errors. Thanks Brian Candler. #1161/#1162
  * All authentication errors now properly raise AuthenticationError.
      AuthenticationError is now a subclass of ConnectionError, which will
      cause the connection to be disconnected and cleaned up appropriately.
      #923
  * Add READONLY and READWRITE commands. Thanks @theodesp. #1114
  * Remove selectors in favor of nonblocking sockets. Selectors had
      issues in some environments including eventlet and gevent. This should
      resolve those issues with no other side effects.
  * Fixed an issue with XCLAIM and previously claimed but not removed
      messages. Thanks @thomdask. #1192/#1191
  * Allow for single connection client instances. These instances
      are not thread safe but offer other benefits including a subtle
      performance increase.
  * Added extensive health checks that keep the connections lively.
      Passing the "health_check_interval=N" option to the Redis client class
      or to a ConnectionPool ensures that a round trip PING/PONG is successful
      before any command if the underlying connection has been idle for more
      than N seconds. ConnectionErrors and TimeoutErrors are automatically
      retried once for health checks.
  * Changed the PubSubWorkerThread to use a threading.Event object rather
      than a boolean to control the thread's life cycle. Thanks Timothy
      Rule. #1194/#1195.
  * Fixed a bug in Pipeline error handling that would incorrectly retry
      ConnectionErrors.
* 3.2.1
  * Fix SentinelConnectionPool to work in multiprocess/forked environments.
* 3.2.0
  * Added support for `select.poll` to test whether data can be read
      on a socket. This should allow for significantly more connections to
      be used with pubsub. Fixes #486/#1115
  * Attempt to guarantee that the ConnectionPool hands out healthy
      connections. Healthy connections are those that have an established
      socket connection to the Redis server, are ready to accept a command
      and have no data available to read. Fixes #1127/#886
  * Use the socket.IPPROTO_TCP constant instead of socket.SOL_TCP.
      IPPROTO_TCP is available on more interpreters (Jython for instance).
      Thanks @Junnplus. #1130
  * Fixed a regression introduced in 3.0 that mishandles exceptions not
      derived from the base Exception class. KeyboardInterrupt and
      gevent.timeout notable. Thanks Christian Fersch. #1128/#1129
  * Significant improvements to handing connections with forked processes.
      Parent and child processes no longer trample on each others' connections.
      Thanks to Jay Rolette for the patch and highlighting this issue.
      #504/#732/#784/#863
  * PythonParser no longer closes the associated connection's socket. The
      connection itself will close the socket. #1108/#1085
* 3.1.0
  * Connection URLs must have one of the following schemes:
      redis://, rediss://, unix://. Thanks @jdupl123. #961/#969
  * Fixed an issue with retry_on_timeout logic that caused some TimeoutErrors
      to be retried. Thanks Aaron Yang. #1022/#1023
  * Added support for SNI for SSL. Thanks @oridistor and Roey Prat. #1087
  * Fixed ConnectionPool repr for pools with no connections. Thanks
      Cody Scott. #1043/#995
  * Fixed GEOHASH to return a None value when specifying a place that
      doesn't exist on the server. Thanks @guybe7. #1126
  * Fixed XREADGROUP to return an empty dictionary for messages that
      have been deleted but still exist in the unacknowledged queue. Thanks
      @xeizmendi. #1116
  * Added an owned method to Lock objects. owned returns a boolean
      indicating whether the current lock instance still owns the lock.
      Thanks Dave Johansen. #1112
  * Allow lock.acquire() to accept an optional token argument. If
      provided, the token argument is used as the unique value used to claim
      the lock. Thankd Dave Johansen. #1112
  * Added a reacquire method to Lock objects. reacquire attempts to renew
      the lock such that the timeout is extended to the same value that the
      lock was initially acquired with. Thanks Ihor Kalnytskyi. #1014
  * Stream names found within XREAD and XREADGROUP responses now properly
      respect the decode_responses flag.
  * XPENDING_RANGE now requires the user the specify the min, max and
      count arguments. Newer versions of Redis prevent count from being
      infinite so it's left to the user to specify these values explicitly.
  * ZADD now returns None when xx=True and incr=True and an element
      is specified that doesn't exist in the sorted set. This matches
      what the server returns in this case. #1084
  * Added client_kill_filter that accepts various filters to identify
      and kill clients. Thanks Theofanis Despoudis. #1098
  * Fixed a race condition that occurred when unsubscribing and
      resubscribing to the same channel or pattern in rapid succession.
      Thanks Marcin Raczyński. #764
  * Added a LockNotOwnedError that is raised when trying to extend or
      release a lock that is no longer owned. This is a subclass of LockError
      so previous code should continue to work as expected. Thanks Joshua
      Harlow. #1095
  * Fixed a bug in GEORADIUS that forced decoding of places without
      respecting the decode_responses option. Thanks Bo Bayles. #1082
* 3.0.1
  * Fixed regression with UnixDomainSocketConnection caused by 3.0.0.
      Thanks Jyrki Muukkonen
  * Fixed an issue with the new asynchronous flag on flushdb and flushall.
      Thanks rogeryen
  * Updated Lock.locked() method to indicate whether *any* process has
      acquired the lock, not just the current one. This is in line with
      the behavior of threading.Lock. Thanks Alan Justino da Silva
* 3.0.0
  BACKWARDS INCOMPATIBLE CHANGES
  * When using a Lock as a context manager and the lock fails to be acquired
      a LockError is now raised. This prevents the code block inside the
      context manager from being executed if the lock could not be acquired.
  * Renamed LuaLock to Lock.
  * Removed the pipeline based Lock implementation in favor of the LuaLock
      implementation.
  * Only bytes, strings and numbers (ints, longs and floats) are acceptable
      for keys and values. Previously redis-py attempted to cast other types
      to str() and store the result. This caused must confusion and frustration
      when passing boolean values (cast to 'True' and 'False') or None values
      (cast to 'None'). It is now the user's responsibility to cast all
      key names and values to bytes, strings or numbers before passing the
      value to redis-py.
  * The StrictRedis class has been renamed to Redis. StrictRedis will
      continue to exist as an alias of Redis for the foreseeable future.
  * The legacy Redis client class has been removed. It caused much confusion
      to users.
  * ZINCRBY arguments 'value' and 'amount' have swapped order to match the
      the Redis server. The new argument order is: keyname, amount, value.
  * MGET no longer raises an error if zero keys are passed in. Instead an
      empty list is returned.
  * MSET and MSETNX now require all keys/values to be specified in a single
      dictionary argument named mapping. This was changed to allow for future
      options to these commands in the future.
  * ZADD now requires all element names/scores be specified in a single
      dictionary argument named mapping. This was required to allow the NX,
      XX, CH and INCR options to be specified.
  * ssl_cert_reqs now has a default value of 'required' by default. This
      should make connecting to a remote Redis server over SSL more secure.
      Thanks u2mejc
  * Removed support for EOL Python 2.6 and 3.3. Thanks jdufresne
  OTHER CHANGES
  * Added missing DECRBY command. Thanks derek-dchu
  * CLUSTER INFO and CLUSTER NODES responses are now properly decoded to
      strings.
  * Added a 'locked()' method to Lock objects. This method returns True
      if the lock has been acquired and owned by the current process,
      otherwise False.
  * EXISTS now supports multiple keys. It's return value is now the number
      of keys in the list that exist.
  * Ensure all commands can accept key names as bytes. This fixes issues
      with BLPOP, BRPOP and SORT.
  * All errors resulting from bad user input are raised as DataError
      exceptions. DataError is a subclass of RedisError so this should be
      transparent to anyone previously catching these.
  * Added support for NX, XX, CH and INCR options to ZADD
  * Added support for the MIGRATE command
  * Added support for the MEMORY USAGE and MEMORY PURGE commands. Thanks
      Itamar Haber
  * Added support for the 'asynchronous' argument to FLUSHDB and FLUSHALL
      commands. Thanks Itamar Haber
  * Added support for the BITFIELD command. Thanks Charles Leifer and
      Itamar Haber
  * Improved performance on pipeline requests with large chunks of data.
      Thanks tzickel
  * Fixed test suite to not fail if another client is connected to the
      server the tests are running against.
  * Added support for SWAPDB. Thanks Itamar Haber
  * Added support for all STREAM commands. Thanks Roey Prat and Itamar Haber
  * SHUTDOWN now accepts the 'save' and 'nosave' arguments. Thanks
      dwilliams-kenzan
  * Added support for ZPOPMAX, ZPOPMIN, BZPOPMAX, BZPOPMIN. Thanks
      Itamar Haber
  * Added support for the 'type' argument in CLIENT LIST. Thanks Roey Prat
  * Added support for CLIENT PAUSE. Thanks Roey Prat
  * Added support for CLIENT ID and CLIENT UNBLOCK. Thanks Itamar Haber
  * GEODIST now returns a None value when referencing a place that does
      not exist. Thanks qingping209
  * Added a ping() method to pubsub objects. Thanks krishan-carbon
  * Fixed a bug with keys in the INFO dict that contained ':' symbols.
      Thanks mzalimeni
  * Fixed the select system call retry compatibility with Python 2.x.
      Thanks lddubeau
  * max_connections is now a valid querystring argument for creating
      connection pools from URLs. Thanks mmaslowskicc
  * Added the UNLINK command. Thanks yozel
  * Added socket_type option to Connection for configurability.
      Thanks garlicnation
  * Lock.do_acquire now atomically sets acquires the lock and sets the
      expire value via set(nx=True, px=timeout). Thanks 23doors
  * Added 'count' argument to SPOP. Thanks AlirezaSadeghi
  * Fixed an issue parsing client_list responses that contained an '='.
      Thanks swilly22
* 2.10.6
  * Various performance improvements. Thanks cjsimpson
  * Fixed a bug with SRANDMEMBER where the behavior for `number=0` did
      not match the spec. Thanks Alex Wang
  * Added HSTRLEN command. Thanks Alexander Putilin
  * Added the TOUCH command. Thanks Anis Jonischkeit
  * Remove unnecessary calls to the server when registering Lua scripts.
      Thanks Ben Greenberg
  * SET's EX and PX arguments now allow values of zero. Thanks huangqiyin
  * Added PUBSUB {CHANNELS, NUMPAT, NUMSUB} commands. Thanks Angus Pearson
  * PubSub connections that encounter `InterruptedError`s now
      retry automatically. Thanks Carlton Gibson and Seth M. Larson
  * LPUSH and RPUSH commands run on PyPy now correctly returns the number
      of items of the list. Thanks Jeong YunWon
  * Added support to automatically retry socket EINTR errors. Thanks
      Thomas Steinacher
  * PubSubWorker threads started with `run_in_thread` are now daemonized
      so the thread shuts down when the running process goes away. Thanks
      Keith Ainsworth
  * Added support for GEO commands. Thanks Pau Freixes, Alex DeBrie and
      Abraham Toriz
  * Made client construction from URLs smarter. Thanks Tim Savage
  * Added support for CLUSTER * commands. Thanks Andy Huang
  * The RESTORE command now accepts an optional `replace` boolean.
      Thanks Yoshinari Takaoka
  * Attempt to connect to a new Sentinel if a TimeoutError occurs. Thanks
      Bo Lopker
  * Fixed a bug in the client's `__getitem__` where a KeyError would be
      raised if the value returned by the server is an empty string.
      Thanks Javier Candeira.
  * Socket timeouts when connecting to a server are now properly raised
      as TimeoutErrors.
* 2.10.5
  * Allow URL encoded parameters in Redis URLs. Characters like a "/" can
      now be URL encoded and redis-py will correctly decode them. Thanks
      Paul Keene.
  * Added support for the WAIT command. Thanks <https://github.com/eshizhan>
  * Better shutdown support for the PubSub Worker Thread. It now properly
      cleans up the connection, unsubscribes from any channels and patterns
      previously subscribed to and consumes any waiting messages on the socket.
  * Added the ability to sleep for a brief period in the event of a
      WatchError occurring. Thanks Joshua Harlow.
  * Fixed a bug with pipeline error reporting when dealing with characters
      in error messages that could not be encoded to the connection's
      character set. Thanks Hendrik Muhs.
  * Fixed a bug in Sentinel connections that would inadvertently connect
      to the master when the connection pool resets. Thanks
      <https://github.com/df3n5>
  * Better timeout support in Pubsub get_message. Thanks Andy Isaacson.
  * Fixed a bug with the HiredisParser that would cause the parser to
      get stuck in an endless loop if a specific number of bytes were
      delivered from the socket. This fix also increases performance of
      parsing large responses from the Redis server.
  * Added support for ZREVRANGEBYLEX.
  * ConnectionErrors are now raised if Redis refuses a connection due to
      the maxclients limit being exceeded. Thanks Roman Karpovich.
  * max_connections can now be set when instantiating client instances.
      Thanks Ohad Perry.
* 2.10.4
    (skipped due to a PyPI snafu)
* 2.10.3
  * Fixed a bug with the bytearray support introduced in 2.10.2. Thanks
      Josh Owen.
* 2.10.2
  * Added support for Hiredis's new bytearray support. Thanks
      <https://github.com/tzickel>
  * POSSIBLE BACKWARDS INCOMPATIBLE CHANGE: Fixed a possible race condition
      when multiple threads share the same Lock instance with a timeout. Lock
      tokens are now stored in thread local storage by default. If you have
      code that acquires a lock in one thread and passes that lock instance to
      another thread to release it, you need to disable thread local storage.
      Refer to the doc strings on the Lock class about the thread_local
      argument information.
  * Fixed a regression in from_url where "charset" and "errors" weren't
      valid options. "encoding" and "encoding_errors" are still accepted
      and preferred.
  * The "charset" and "errors" options have been deprecated. Passing
      either to StrictRedis.__init__ or from_url will still work but will
      also emit a DeprecationWarning. Instead use the "encoding" and
      "encoding_errors" options.
  * Fixed a compatibility bug with Python 3 when the server closes a
      connection.
  * Added BITPOS command. Thanks <https://github.com/jettify>.
  * Fixed a bug when attempting to send large values to Redis in a Pipeline.
* 2.10.1
  * Fixed a bug where Sentinel connections to a server that's no longer a
      master and receives a READONLY error will disconnect and reconnect to
      the master.
* 2.10.0
  * Discontinued support for Python 2.5. Upgrade. You'll be happier.
  * The HiRedis parser will now properly raise ConnectionErrors.
  * Completely refactored PubSub support. Fixes all known PubSub bugs and
      adds a bunch of new features. Docs can be found in the README under the
      new "Publish / Subscribe" section.
  * Added the new HyperLogLog commands (PFADD, PFCOUNT, PFMERGE). Thanks
      Pepijn de Vos and Vincent Ohprecio.
  * Updated TTL and PTTL commands with Redis 2.8+ semantics. Thanks Markus
      Kaiserswerth.
  * *SCAN commands now return a long (int on Python3) cursor value rather
      than the string representation. This might be slightly backwards
incompatible in code using*SCAN commands loops such as
      "while cursor != '0':".
  * Added extra *SCAN commands that return iterators instead of the normal
      [cursor, data] type. Use scan_iter, hscan_iter, sscan_iter, and
      zscan_iter for iterators. Thanks Mathieu Longtin.
  * Added support for SLOWLOG commands. Thanks Rick van Hattem.
  * Added lexicographical commands ZRANGEBYLEX, ZREMRANGEBYLEX, and ZLEXCOUNT
      for sorted sets.
  * Connection objects now support an optional argument, socket_read_size,
      indicating how much data to read during each socket.recv() call. After
      benchmarking, increased the default size to 64k, which dramatically
      improves performance when fetching large values, such as many results
      in a pipeline or a large (>1MB) string value.
  * Improved the pack_command and send_packed_command functions to increase
      performance when sending large (>1MB) values.
  * Sentinel Connections to master servers now detect when a READONLY error
      is encountered and disconnect themselves and all other active connections
      to the same master so that the new master can be discovered.
  * Fixed Sentinel state parsing on Python 3.
  * Added support for SENTINEL MONITOR, SENTINEL REMOVE, and SENTINEL SET
      commands. Thanks Greg Murphy.
  * INFO output that doesn't follow the "key:value" format will now be
      appended to a key named "__raw__" in the INFO dictionary. Thanks Pedro
      Larroy.
  * The "vagrant" directory contains a complete vagrant environment for
      redis-py developers. The environment runs a Redis master, a Redis slave,
      and 3 Sentinels. Future iterations of the test suite will incorporate
      more integration style tests, ensuring things like failover happen
      correctly.
  * It's now possible to create connection pool instances from a URL.
      StrictRedis.from_url() now uses this feature to create a connection pool
      instance and use that when creating a new client instance. Thanks
      <https://github.com/chillipino>
  * When creating client instances or connection pool instances from an URL,
      it's now possible to pass additional options to the connection pool with
      querystring arguments.
  * Fixed a bug where some encodings (like utf-16) were unusable on Python 3
      as command names and literals would get encoded.
  * Added an SSLConnection class that allows for secure connections through
      stunnel or other means. Construct an SSL connection with the ssl=True
      option on client classes, using the rediss:// scheme from an URL, or
      by passing the SSLConnection class to a connection pool's
      connection_class argument. Thanks <https://github.com/oranagra>.
  * Added a socket_connect_timeout option to control how long to wait while
      establishing a TCP connection before timing out. This lets the client
      fail fast when attempting to connect to a downed server while keeping
      a more lenient timeout for all other socket operations.
  * Added TCP Keep-alive support by passing use the socket_keepalive=True
      option. Finer grain control can be achieved using the
      socket_keepalive_options option which expects a dictionary with any of
      the keys (socket.TCP_KEEPIDLE, socket.TCP_KEEPCNT, socket.TCP_KEEPINTVL)
      and integers for values. Thanks Yossi Gottlieb.
  * Added a `retry_on_timeout` option that controls how socket.timeout errors
      are handled. By default it is set to False and will cause the client to
      raise a TimeoutError anytime a socket.timeout is encountered. If
      `retry_on_timeout` is set to True, the client will retry a command that
      timed out once like other `socket.error`s.
  * Completely refactored the Lock system. There is now a LuaLock class
      that's used when the Redis server is capable of running Lua scripts along
      with a fallback class for Redis servers < 2.6. The new locks fix several
      subtle race consider that the old lock could face. In additional, a
      new method, "extend" is available on lock instances that all a lock
      owner to extend the amount of time they have the lock for. Thanks to
      Eli Finkelshteyn and <https://github.com/chillipino> for contributions.
* 2.9.1
  * IPv6 support. Thanks <https://github.com/amashinchi>
* 2.9.0
  * Performance improvement for packing commands when using the PythonParser.
      Thanks Guillaume Viot.
  * Executing an empty pipeline transaction no longer sends MULTI/EXEC to
      the server. Thanks EliFinkelshteyn.
  * Errors when authenticating (incorrect password) and selecting a database
      now close the socket.
  * Full Sentinel support thanks to Vitja Makarov. Thanks!
  * Better repr support for client and connection pool instances. Thanks
      Mark Roberts.
  * Error messages that the server sends to the client are now included
      in the client error message. Thanks Sangjin Lim.
  * Added the SCAN, SSCAN, HSCAN, and ZSCAN commands. Thanks Jingchao Hu.
  * ResponseErrors generated by pipeline execution provide addition context
      including the position of the command in the pipeline and the actual
      command text generated the error.
  * ConnectionPools now play nicer in threaded environments that fork. Thanks
      Christian Joergensen.
* 2.8.0
  * redis-py should play better with gevent when a gevent Timeout is raised.
      Thanks leifkb.
  * Added SENTINEL command. Thanks Anna Janackova.
  * Fixed a bug where pipelines could potentially corrupt a connection
      if the MULTI command generated a ResponseError. Thanks EliFinkelshteyn
      for the report.
  * Connections now call socket.shutdown() prior to socket.close() to
      ensure communication ends immediately per the note at
      <https://docs.python.org/2/library/socket.html#socket.socket.close>
      Thanks to David Martin for pointing this out.
  * Lock checks are now based on floats rather than ints. Thanks
      Vitja Makarov.
* 2.7.6
  * Added CONFIG RESETSTAT command. Thanks Yossi Gottlieb.
  * Fixed a bug introduced in 2.7.3 that caused issues with script objects
      and pipelines. Thanks Carpentier Pierre-Francois.
  * Converted redis-py's test suite to use the awesome py.test library.
  * Fixed a bug introduced in 2.7.5 that prevented a ConnectionError from
      being raised when the Redis server is LOADING data.
  * Added a BusyLoadingError exception that's raised when the Redis server
      is starting up and not accepting commands yet. BusyLoadingError
      subclasses ConnectionError, which this state previously returned.
      Thanks Yossi Gottlieb.
* 2.7.5
  * DEL, HDEL and ZREM commands now return the numbers of keys deleted
      instead of just True/False.
  * from_url now supports URIs with a port number. Thanks Aaron Westendorf.
* 2.7.4
  * Added missing INCRBY method. Thanks Krzysztof Dorosz.
  * SET now accepts the EX, PX, NX and XX options from Redis 2.6.12. These
      options will generate errors if these options are used when connected
      to a Redis server < 2.6.12. Thanks George Yoshida.
* 2.7.3
  * Fixed a bug with BRPOPLPUSH and lists with empty strings.
  * All empty except: clauses have been replaced to only catch Exception
      subclasses. This prevents a KeyboardInterrupt from triggering exception
      handlers. Thanks Lucian Branescu Mihaila.
  * All exceptions that are the result of redis server errors now share a
      command Exception subclass, ServerError. Thanks Matt Robenolt.
  * Prevent DISCARD from being called if MULTI wasn't also called. Thanks
      Pete Aykroyd.
  * SREM now returns an integer indicating the number of items removed from
      the set. Thanks <https://github.com/ronniekk>.
  * Fixed a bug with BGSAVE and BGREWRITEAOF response callbacks with Python3.
      Thanks Nathan Wan.
  * Added CLIENT GETNAME and CLIENT SETNAME commands.
      Thanks <https://github.com/bitterb>.
  * It's now possible to use len() on a pipeline instance to determine the
      number of commands that will be executed. Thanks Jon Parise.
  * Fixed a bug in INFO's parse routine with floating point numbers. Thanks
      Ali Onur Uyar.
  * Fixed a bug with BITCOUNT to allow `start` and `end` to both be zero.
      Thanks Tim Bart.
  * The transaction() method now accepts a boolean keyword argument,
      value_from_callable. By default, or if False is passes, the transaction()
      method will return the value of the pipelines execution. Otherwise, it
      will return whatever func() returns.
  * Python3 compatibility fix ensuring we're not already bytes(). Thanks
      Salimane Adjao Moustapha.
  * Added PSETEX. Thanks YAMAMOTO Takashi.
  * Added a BlockingConnectionPool to limit the number of connections that
      can be created. Thanks James Arthur.
  * SORT now accepts a `groups` option that if specified, will return
      tuples of n-length, where n is the number of keys specified in the GET
      argument. This allows for convenient row-based iteration. Thanks
      Ionuț Arțăriși.
* 2.7.2
  * Parse errors are now *always* raised on multi/exec pipelines, regardless
      of the `raise_on_error` flag. See
      <https://groups.google.com/forum/?hl=en&fromgroups=#!topic/redis-db/VUiEFT8U8U0>
      for more info.
* 2.7.1
  * Packaged tests with source code
* 2.7.0
  * Added BITOP and BITCOUNT commands. Thanks Mark Tozzi.
  * Added the TIME command. Thanks Jason Knight.
  * Added support for LUA scripting. Thanks to Angus Peart, Drew Smathers,
      Issac Kelly, Louis-Philippe Perron, Sean Bleier, Jeffrey Kaditz, and
      Dvir Volk for various patches and contributions to this feature.
  * Changed the default error handling in pipelines. By default, the first
      error in a pipeline will now be raised. A new parameter to the
      pipeline's execute, `raise_on_error`, can be set to False to keep the
      old behavior of embeedding the exception instances in the result.
  * Fixed a bug with pipelines where parse errors won't corrupt the
      socket.
  * Added the optional `number` argument to SRANDMEMBER for use with
      Redis 2.6+ servers.
  * Added PEXPIRE/PEXPIREAT/PTTL commands. Thanks Luper Rouch.
  * Added INCRBYFLOAT/HINCRBYFLOAT commands. Thanks Nikita Uvarov.
  * High precision floating point values won't lose their precision when
      being sent to the Redis server. Thanks Jason Oster and Oleg Pudeyev.
  * Added CLIENT LIST/CLIENT KILL commands
* 2.6.2
  * `from_url` is now available as a classmethod on client classes. Thanks
      Jon Parise for the patch.
  * Fixed several encoding errors resulting from the Python 3.x support.
* 2.6.1
  * Python 3.x support! Big thanks to Alex Grönholm.
  * Fixed a bug in the PythonParser's read_response that could hide an error
      from the client (#251).
* 2.6.0
  * Changed (p)subscribe and (p)unsubscribe to no longer return messages
      indicating the channel was subscribed/unsubscribed to. These messages
      are available in the listen() loop instead. This is to prevent the
      following scenario:
    * Client A is subscribed to "foo"
    * Client B publishes message to "foo"
    * Client A subscribes to channel "bar" at the same time.
      Prior to this change, the subscribe() call would return the published
      messages on "foo" rather than the subscription confirmation to "bar".
  * Added support for GETRANGE, thanks Jean-Philippe Caruana
  * A new setting "decode_responses" specifies whether return values from
      Redis commands get decoded automatically using the client's charset
      value. Thanks to Frankie Dintino for the patch.
* 2.4.13
  * redis.from_url() can take an URL representing a Redis connection string
      and return a client object. Thanks Kenneth Reitz for the patch.
* 2.4.12
  * ConnectionPool is now fork-safe. Thanks Josiah Carson for the patch.
* 2.4.11
  * AuthenticationError will now be correctly raised if an invalid password
      is supplied.
  * If Hiredis is unavailable, the HiredisParser will raise a RedisError
      if selected manually.
  * Made the INFO command more tolerant of Redis changes formatting. Fix
      for #217.
* 2.4.10
  * Buffer reads from socket in the PythonParser. Fix for a Windows-specific
      bug (#205).
  * Added the OBJECT and DEBUG OBJECT commands.
  * Added __del__ methods for classes that hold on to resources that need to
      be cleaned up. This should prevent resource leakage when these objects
      leave scope due to misuse or unhandled exceptions. Thanks David Wolever
      for the suggestion.
  * Added the ECHO command for completeness.
  * Fixed a bug where attempting to subscribe to a PubSub channel of a Redis
      server that's down would blow out the stack. Fixes #179 and #195. Thanks
      Ovidiu Predescu for the test case.
  * StrictRedis's TTL command now returns a -1 when querying a key with no
      expiration. The Redis class continues to return None.
  * ZADD and SADD now return integer values indicating the number of items
      added. Thanks Homer Strong.
  * Renamed the base client class to StrictRedis, replacing ZADD and LREM in
      favor of their official argument order. The Redis class is now a subclass
      of StrictRedis, implementing the legacy redis-py implementations of ZADD
      and LREM. Docs have been updated to suggesting the use of StrictRedis.
  * SETEX in StrictRedis is now compliant with official Redis SETEX command.
      the name, value, time implementation moved to "Redis" for backwards
      compatibility.
* 2.4.9
  * Removed socket retry logic in Connection. This is the responsibility of
      the caller to determine if the command is safe and can be retried. Thanks
      David Wolver.
  * Added some extra guards around various types of exceptions being raised
      when sending or parsing data. Thanks David Wolver and Denis Bilenko.
* 2.4.8
  * Imported with_statement from __future__ for Python 2.5 compatibility.
* 2.4.7
  * Fixed a bug where some connections were not getting released back to the
      connection pool after pipeline execution.
  * Pipelines can now be used as context managers. This is the preferred way
      of use to ensure that connections get cleaned up properly. Thanks
      David Wolever.
  * Added a convenience method called transaction() on the base Redis class.
      This method eliminates much of the boilerplate used when using pipelines
      to watch Redis keys. See the documentation for details on usage.
* 2.4.6
  * Variadic arguments for SADD, SREM, ZREN, HDEL, LPUSH, and RPUSH. Thanks
      Raphaël Vinot.
  * (CRITICAL) Fixed an error in the Hiredis parser that occasionally caused
      the socket connection to become corrupted and unusable. This became
      noticeable once connection pools started to be used.
  * ZRANGE, ZREVRANGE, ZRANGEBYSCORE, and ZREVRANGEBYSCORE now take an
      additional optional argument, score_cast_func, which is a callable used
      to cast the score value in the return type. The default is float.
  * Removed the PUBLISH method from the PubSub class. Connections that are
      [P]SUBSCRIBEd cannot issue PUBLISH commands, so it doesn't make sense
      to have it here.
  * Pipelines now contain WATCH and UNWATCH. Calling WATCH or UNWATCH from
      the base client class will result in a deprecation warning. After
      WATCHing one or more keys, the pipeline will be placed in immediate
      execution mode until UNWATCH or MULTI are called. Refer to the new
      pipeline docs in the README for more information. Thanks to David Wolever
      and Randall Leeds for greatly helping with this.
* 2.4.5
  * The PythonParser now works better when reading zero length strings.
* 2.4.4
  * Fixed a typo introduced in 2.4.3
* 2.4.3
  * Fixed a bug in the UnixDomainSocketConnection caused when trying to
      form an error message after a socket error.
* 2.4.2
  * Fixed a bug in pipeline that caused an exception while trying to
      reconnect after a connection timeout.
* 2.4.1
  * Fixed a bug in the PythonParser if disconnect is called before connect.
* 2.4.0
  * WARNING: 2.4 contains several backwards incompatible changes.
  * Completely refactored Connection objects. Moved much of the Redis
      protocol packing for requests here, and eliminated the nasty dependencies
      it had on the client to do AUTH and SELECT commands on connect.
  * Connection objects now have a parser attribute. Parsers are responsible
      for reading data Redis sends. Two parsers ship with redis-py: a
      PythonParser and the HiRedis parser. redis-py will automatically use the
      HiRedis parser if you have the Python hiredis module installed, otherwise
      it will fall back to the PythonParser. You can force or the other, or even
      an external one by passing the `parser_class` argument to ConnectionPool.
  * Added a UnixDomainSocketConnection for users wanting to talk to the Redis
      instance running on a local machine only. You can use this connection
      by passing it to the `connection_class` argument of the ConnectionPool.
  * Connections no longer derive from threading.local. See threading.local
      note below.
  * ConnectionPool has been completely refactored. The ConnectionPool now
      maintains a list of connections. The redis-py client only hangs on to
      a ConnectionPool instance, calling get_connection() anytime it needs to
      send a command. When get_connection() is called, the command name and
      any keys involved in the command are passed as arguments. Subclasses of
      ConnectionPool could use this information to identify the shard the keys
      belong to and return a connection to it. ConnectionPool also implements
      disconnect() to force all connections in the pool to disconnect from
      the Redis server.
  * redis-py no longer support the SELECT command. You can still connect to
      a specific database by specifying it when instantiating a client instance
      or by creating a connection pool. If you need to talk to multiple
      databases within your application, you should use a separate client
      instance for each database you want to talk to.
  * Completely refactored Publish/Subscribe support. The subscribe and listen
      commands are no longer available on the redis-py Client class. Instead,
      the `pubsub` method returns an instance of the PubSub class which contains
      all publish/subscribe support. Note, you can still PUBLISH from the
      redis-py client class if you desire.
  * Removed support for all previously deprecated commands or options.
  * redis-py no longer uses threading.local in any way. Since the Client
      class no longer holds on to a connection, it's no longer needed. You can
      now pass client instances between threads, and commands run on those
      threads will retrieve an available connection from the pool, use it and
      release it. It should now be trivial to use redis-py with eventlet or
      greenlet.
  * ZADD now accepts pairs of value=score keyword arguments. This should help
      resolve the long standing #72. The older value and score arguments have
      been deprecated in favor of the keyword argument style.
  * Client instances now get their own copy of RESPONSE_CALLBACKS. The new
      set_response_callback method adds a user defined callback to the instance.
  * Support Jython, fixing #97. Thanks to Adam Vandenberg for the patch.
  * Using __getitem__ now properly raises a KeyError when the key is not
      found. Thanks Ionuț Arțăriși for the patch.
  * Newer Redis versions return a LOADING message for some commands while
      the database is loading from disk during server start. This could cause
      problems with SELECT. We now force a socket disconnection prior to
      raising a ResponseError so subsequent connections have to reconnect and
      re-select the appropriate database. Thanks to Benjamin Anderson for
      finding this and fixing.
* 2.2.4
  * WARNING: Potential backwards incompatible change - Changed order of
      parameters of ZREVRANGEBYSCORE to match those of the actual Redis command.
      This is only backwards-incompatible if you were passing max and min via
      keyword args. If passing by normal args, nothing in user code should have
      to change. Thanks Stéphane Angel for the fix.
  * Fixed INFO to properly parse the Redis data correctly for both 2.2.x and
      2.3+. Thanks Stéphane Angel for the fix.
  * Lock objects now store their timeout value as a float. This allows floats
      to be used as timeout values. No changes to existing code required.
  * WATCH now supports multiple keys. Thanks Rich Schumacher.
  * Broke out some code that was Python 2.4 incompatible. redis-py should
      now be usable on 2.4, but this hasn't actually been tested. Thanks
      Dan Colish for the patch.
  * Optimized some code using izip and islice. Should have a pretty good
      speed up on larger data sets. Thanks Dan Colish.
  * Better error handling when submitting an empty mapping to HMSET. Thanks
      Dan Colish.
  * Subscription status is now reset after every (re)connection.
* 2.2.3
  * Added support for Hiredis. To use, simply "pip install hiredis" or
      "easy_install hiredis". Thanks for Pieter Noordhuis for the hiredis-py
      bindings and the patch to redis-py.
  * The connection class is chosen based on whether hiredis is installed
      or not. To force the use of the PythonConnection, simply create
      your own ConnectionPool instance with the connection_class argument
      assigned to to PythonConnection class.
  * Added missing command ZREVRANGEBYSCORE. Thanks Jay Baird for the patch.
  * The INFO command should be parsed correctly on 2.2.x server versions
      and is backwards compatible with older versions. Thanks Brett Hoerner.
* 2.2.2
  * Fixed a bug in ZREVRANK where retrieving the rank of a value not in
      the zset would raise an error.
  * Fixed a bug in Connection.send where the errno import was getting
      overwritten by a local variable.
  * Fixed a bug in SLAVEOF when promoting an existing slave to a master.
  * Reverted change of download URL back to redis-VERSION.tar.gz. 2.2.1's
      change of this actually broke Pypi for Pip installs. Sorry!
* 2.2.1
  * Changed archive name to redis-py-VERSION.tar.gz to not conflict
      with the Redis server archive.
* 2.2.0
  * Implemented SLAVEOF
  * Implemented CONFIG as config_get and config_set
  * Implemented GETBIT/SETBIT
  * Implemented BRPOPLPUSH
  * Implemented STRLEN
  * Implemented PERSIST
  * Implemented SETRANGE
  * Changed type annotation of the `num` parameter in `zrange` from `int` to `Optional[int]