Ruby : Code Snippets - How to Mass renaming files with specific extension

folder_path = "C:\\MyDocs\\Work\\Venture\\eStore\\New folder"

puts "Renaming files..."

puts folder_path

Dir.open(folder_path).each do |p|

  next if File.extname(p) != ".mp4"

  filename = File.basename(p)

  newname = filename.gsub 'School - Episode ', 'School - Episode 0' 

  newname = newname 

  puts "#{folder_path}/#{p} #{folder_path}/#{newname}"

  File.rename( "#{folder_path}/#{p}", "#{folder_path}/#{newname}")

end

puts "Renaming complete."