title: SerialTimeoutException in Python not working as expected
body: <p>Sometimes I do not get any data in via the serial interface and I want to catch this case with an exception in the following way:</p>
  
  <pre><code>ser          = serial.Serial(3)
  ser.baudrate = 115200
  timeout      = 1
  
  while (some condidion)
    try:
      dump = ser.read(40)
    except ser1.SerialTimeoutException:
      print('Data could not be read')
  
  ser.close()
  </code></pre>
  
  <p>However, when I run this program, the exception is never caught when no
  data is in the buffer and I am stuck in an endless loop. Anyone an idea
  what I am doing wrong here?</p>