title: how to decode dart encoded readAsBytesSync() string in python
body: <p>I am sending file type image to cloud server written in python. First of all, I am getting the content of file as list of bytes, then I am converting it to json to send to server.</p>
  
  <pre><code>List&lt;int&gt; imageBytes = img.readAsBytesSync();
  var my_json = {"img":imageBytes};
  var encoded = json.encode(my_json);
  var channel =  IOWebSocketChannel.connect("ws://34.73.158.146:5903");
  channel.sink.add(encoded);
  </code></pre>
  
  <p>So, please tell me how do readAsBytesSync() convert image to bytes, and how can I convert it back to image in python.
  Also please tell me, what is the most appropriate way to encode and decode file type image in flutter?</p>