The reason why the Python Webserver sends your PHP files to the brower is likely because it is not configured or able to handle PHP files. See https://serverfault.com/questions/338394/how-to-run-php-with-simplehttpserver
PHP 5.4 has a built-in webserver. You can call it from the command line like this:
php [options] -S <addr>:<port> [-t docroot]
Example
C:\Users\Gordon>php -S 127.0.0.1:80 -t .
PHP 5.4.0 Development Server started at Sun Sep 02 14:20:28 2012
Listening on 127.0.0.1:80
Document root is C:\Users\Gordon
Press Ctrl-C to quit.
Note that if you omit -t PHP will use the current working directory.