Sage's Python

[Akand Islam]

In my system (Ubuntu 10.04) there are sage-4.6, python 2.6.5, tk8.5-
dev installed. When I give command from terminal "sage -f
python-2.6.5.p8" to get sage's python it shows following message:

 No command 'sage' found, did you mean:
 Command 'save' from package 'atfs' (universe)
 Command 'page' from package 'tcllib' (universe)
 sage: command not found

How can I get Sage's python to be worked so that I can import sage.all
in python shell?

Thanks in advance.
--Akand