I have an embedded linux device and here's what I would like to do using python:

Get the device console over serial port. I can do it like this:
>>> ser = serial.Serial('/dev/ttyUSB-17', 115200, timeout=1)
Now I want to run a tail command on the embedded device command line, like this:
# tail -f /var/log/messages

and capture the o/p and display on my python >>> console.
How do I do that ?
very first you need to get log-in into the device.
then you can run the specified command on that device.
note:command which you are going to run must be supported by that device.
Now after opening a serial port using open() you need to find the login prompt using Read() and then write the username using write(), same thing repeat for password.
once you have logged-in you can now run the commands you needed to execute
how to read command output from serial device using python