redis.exceptions.ConnectionError: Error 111 connecting to localhost:6379. Connection refused.

错误：

 File "/py3/lib/python3.6/site-packages/redis/client.py", line 747, in flushdb
    return self.execute_command('FLUSHDB')
  File "/py3/lib/python3.6/site-packages/redis/client.py", line 673, in execute_command
    connection.send_command(*args)
  File "/py3/lib/python3.6/site-packages/redis/connection.py", line 610, in send_command
    self.send_packed_command(self.pack_command(*args))
  File "/py3/lib/python3.6/site-packages/redis/connection.py", line 585, in send_packed_command
    self.connect()
  File "/py3/lib/python3.6/site-packages/redis/connection.py", line 489, in connect
    raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error 111 connecting to 127.0.0.1:6379. Connection refused.

解决方法：

sudo apt-get install redis-server