Python
The easiest way to hide the browser is to install PhantomJS. Then, change this line:
driver = webdriver.Firefox()
to:
driver = webdriver.PhantomJS()
The rest of your code won’t need to be changed and no browser will open. For debugging purposes, use driver.save_screenshot('screen.png')
at different steps of your code or just switch to the Firefox webdriver again.
On Windows, you will have to specify the path to phantomjs.exe:
driver = webdriver.PhantomJS('C:\phantomjs-1.9.7-windows\phantomjs.exe')
Java
Have a look at Ghost Driver: How to run ghostdriver with Selenium using java