How to make remove display from a csv file through an if statement?

I have a csv file which creates a list of items for a directory. I want to make any items with a quantity of 0 to not appear. I am using rails. quantity is a header in the csv just an FYI. In a gist I need an if statement something along the lines of if quantity = 0 then its removed from the list and not displayed.

thanks in advanced. or if there is a better way let me know.