PHP vs Python article from 2 years ago http://onstartups.com/tabid/3339/bid/20493/Why-PHP-Is-Fun-an...
If you are going to use PHP, Laravel 4 framework is probably the best choice https://tutsplus.com/tutorial/why-laravel-is-taking-the-php-...
Symfony 2 and Silex (for small projects) are great frameworks too
But if you already know and love Python, stick to that. It's a great language.