[Tutor] Variables in Os Path ?

[glidedon]

Hi list,

Newbie here, What am I doing wrong here ? When I try to insert my variable 
"file_name" into the path to open a file I get the error at bottom. The path 
is correct if I insert the acutal file name .  BTW this on a BeOS system, if 
you don't recognise the path format :-)

TIA

Don

import os

/snip/

file_query = raw_input( ' Do you have a log already started ?  : y/n ' )

if file_query in ( 'y', 'Y', 'Yes' ):

        file_name = raw_input ( ' Enter file name : ')
        file = open('/boot/home/py/file_name' , 'r')
        history_list = file.readlines()
        file.close()
        for eachline in history_list:
            print eachline,
/snip/

Traceback (most recent call last):
  File "/boot/home/py/IOFile/File_Query.py", line 11, in ?
    file = open('/boot/home/py/filename' , 'r')
IOError: [Errno -2147459069] No such file or directory: '/boot/home/py/
filename'