title: extract Json file to decode in base64
body: <p>with respect,
  I am trig to use the contents of a json file which is encoded with base64.
  I would like to decode the encoded part of the json file. following is my code.</p>
  
  <pre><code>response={"response": [{"objcontent": [{"rowkeys":["time","lat","lon","tos"],"rowvalues": [["AAAAAAAALkA=","AAAAAADgU8A=","AAAAAAAA8D8=","7HitYA"],["AAAAAAAALkA=","AAAAAADgU8A=","AAAAAAAACEA=","7HitYA"],["AAAAAAAALkA=","AAAAAADgU8A=","AAAAAAAAFEA=","7HitYA"]]}]}]}
  
  import base64
  import struct
  for response_i in response['response']:
      a=base64.b64decode(response_i['objcontent'][0]['rowvalues'])
      struct.unpack('12d',a)
  </code></pre>
  
  <p>following is the error which i got.</p>
  
  <pre><code>TypeError: argument should be a bytes-like object or ASCII string, not 'list'
  </code></pre>
  
  <p>May someone give some tips to overcome this issue.
  Thank you.</p>