install pyserial on python 2.7.2

Hi guys

I am writing some code to talk to the serial port
I have installed the Kernal from XCSoar that gives me

/dev/ttyUSB0 when using USB OTG prolific usb-serial adapter

I can read and write to the serila port change baud rate etc via shell

But I want to do some serial stuff in python


the import serial command doesnt work ( as the 2.7.2 does have serial to import )

any suggestions..