Until you forget about it and do something like:

puts "in Python, you can say 'from module import x, y, z'"

which will happily throw an exception because you don't have module/x.rb.

How about this instead?

    def require_multiple(dir, modules)
        modules.each { |m| require "#{dir}/#{m}" }
    end

    require_multiple 'net', %w[http pop ftp]