rename list youtube downloaded files

rename.rb

keyword = "(Part"
files = Dir.entries('.').select{|x| x.include?(keyword)}

files.each do |file|
  wor = file.match(/( \()(.+)(?=.mp4)/)[0]
  num = wor.match(/([0-9]+)/)[0]
  num = (num.to_i < 10)? "#{0}#{num}" : num
  new_name = "#{num}. #{file.gsub(wor, '')}"  
  File.rename(file, "#{Dir.pwd}/#{new_name}")
end