I\'m currently following Zed Shaw\'s book on Python, Learn Python the Hard Way and I\'m learning about functions. I decided to follow some of the extra credit exercises that
In Python 2.x raw_input returns a string. Looking at your code, you could also use input which returns an integer. I would think that would be the most explicit option using Python2.
Then you can treat food as an int throughout your code by using %d instead of %s. When entering a non int your program would throw an exception.