Not support pickle serialized object

[baojiweicn]

When I use 'get' method to get a serialized string from redis :

  val = await redis_connection.get(key)
  File "/usr/local/lib/python3.6/site-packages/asyncio_redis/protocol.py", line 678, in wrapper
    result = yield from post_process(protocol_self, result)
  File "/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6/asyncio/coroutines.py", line 210, in coro
    res = func(*args, **kw)
  File "/usr/local/lib/python3.6/site-packages/asyncio_redis/protocol.py", line 406, in bytes_to_native_or_none
    return protocol.decode_to_native(result)
  File "/usr/local/lib/python3.6/site-packages/asyncio_redis/encoders.py", line 69, in decode_to_native
    return data.decode(self.encoding)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x80 in position 0: invalid start byte 

the serialized string like this :

127.0.0.1:6379> get "oe-session:e1759fc0587fbb933b0cf2422a397b73f2fa6d01"
"\x80\x04\x95M\x00\x00\x00\x00\x00\x00\x00}\x94(\x8c\x05login\x94N\x8c\bpassword\x94N\x8c\x02db\x94\x8c\bethicall\x94\x8c\x03uid\x94N\x8c\acontext\x94}\x94\x8c\x04lang\x94\x8c\x05zh_CN\x94su."

unserialized :

In [4]: from cPickle import loads, dump
In [5]: loads('\x80\x02}q\x01(U\x05loginq\x02NU\x08passwordq\x03NU\x02dbq\x04X\x08\x00\x00\x00ethicallq\x05U\x03uidq\x06NU\x07contextq\x07}q\x08U\x04langq\tU\x05zh_CNq\nsu.')
Out[5]: 
{'context': {'lang': 'zh_CN'},
 'db': u'ethicall',
 'login': None,
 'password': None,
 'uid': None}

fortunately, when I use set it works:

await redis_connection.setex('oe-session:e1759fc0587fbb933b0cf2422a397b73f2fa6d01', 
2592000, 
'\x80\x02}q\x01(U\x05loginq\x02NU\x08passwordq\x03NU\x02dbq\x04X\x08\x00\x00\x00ethicallq\x05U\x03uidq\x06NU\x07contextq\x07}q\x08U\x04langq\tU\x05zh_CNq\nsu.')