redis-py中事物的使用，加锁
>>> r = redis.Redis(...)
>>> r.set('bing', 'baz')
>>> # Use the pipeline() method to create a pipeline instance
>>> pipe = r.pipeline()
>>> # The following SET commands are buffered
>>> pipe.set('foo', 'bar')
>>> pipe.get('bing')
>>> # the EXECUTE call sends all buffered commands to the server, returning
>>> # a list of responses, one for each command.
>>> pipe.execute()
[True, 'baz']
For ease of use, all commands being buffered into the pipeline return the pipeline object itself. Therefore calls can be chained like:
>>> pipe.set('foo', 'bar').sadd('faz', 'baz').incr('auto_number').execute()
[True, True, 6]
In addition, pipelines can also ensure the buffered commands are executed atomically as a group. This happens by default. If you want to disable the atomic nature of a pipeline but still want to buffer commands, you can turn off transactions.
>>> pipe = r.pipeline(transaction=False)