title: Using pySerial with Python 3.3
body: <p>I've seen many code samples using the serial port and people say they are working codes too. The thing is, when I try the code it doesn't work. </p>
  
  <pre><code>import serial
  
  ser = serial.Serial(
      port=0,
      baudrate=9600
      # parity=serial.PARITY_ODD,
      # stopbits=serial.STOPBITS_TWO,
      # bytesize=serial.SEVENBITS
  )
  
  ser.open()
  ser.isOpen()
  
  print(ser.write(0xAA))
  </code></pre>
  
  <p>The error it gives me is : "SerialException: Port is already opened". 
  Is it me using python3.3 the problem or is there something additional I need to instal ? Is there any other way to use COM ports with Python3.3 ? </p>