title: Python PySerial readline function wrong use
body: <p>I'm using a script importing PySerial
  to read from COM4</p>
  
  <p>messages I would like to intercept end with a couple of #</p>
  
  <p>so I tried to use </p>
  
  <pre><code>bus.readline(eol='##')
  </code></pre>
  
  <p>where bus is my connection.</p>
  
  <p>I expected to read like:</p>
  
  <ol>
  <li>*#*3##</li>
  <li>*#*3##</li>
  <li>*#*3##</li>
  </ol>
  
  <p>Unfortunalyy I found also</p>
  
  <ol>
  <li>*#*1##*1*1*99##</li>
  </ol>
  
  <p>that I expected to read spleetted into 2 lines</p>
  
  <ol>
  <li>*#*1##</li>
  <li>*1*1*99##</li>
  </ol>
  
  <p>Clearly readline is not working but why?</p>