title: How can i fill buffer in python like below node.js buffer
body: <p>I am new to python .
  I am writing a simple client that send socket buff to a server. 
  I fill buff in node.js like below,how can i do the same in python?</p>
  
  <pre><code>    var request = new Buffer(length);
      request .writeUInt32BE(command, 0);
      request .writeUInt32BE(length, 4);
      request .writeUInt32BE(seqNo, 8);
  </code></pre>
  
  <p>update , Problem Solved:</p>
  
  <pre class="lang-py prettyprint-override"><code>    buff = struct.pack("&gt;III",0x123abc,0x123,123)
  </code></pre>