Hi , I am working on a project "autonomous robot navigated based GPS " and I have :
Rover 5 platform ,arduino mega 2560, wifi shield ,compass, and GPS nmea 406a , 4 sharp IR sensor.....
I want make interface by python that connect with robot over wifi and with the google earth at my computer >some thing like this project
http://users.libero.it/riccardo.rocca/07_ROBOAT_2011/roboat2011.html
but I don't know if it possible to connect python with arduino wifi ?if some one could help me , plz 
Did you ever get this figured out? I'm trying the same thing and having lots of issues. Got any advice?
but I don't know if it possible to connect python with arduino wifi ?
The WiFi shield lets you connect wirelessly to a server, or to act as a server. Which role is the Arduino going to perform? Seem like it is going to be a server, serving up responses to GET requests (GET turningRight, GET going, GET stopped, GET faster, GET slower, etc.).
As a client, it does not know how the GET request arrived - from a PHP script, from a Python script, from an ASP.NET program, etc.
So, it isn't clear what your problem is. The type of scripting language on the server is NOT the problem, though.