new_contents: #unpack a tuple 's advanced usage
  def unpackatuple(a,b,c):
      return(a+b+c)
  
  a=(1,2,3)
  print(unpackatuple(*a))
  a,b,c=(1,2,3)
  #note it is  a tuple
  print(a,b,c)
  #but in the console,the a,b,c is a tuple,but the above is 1,2,3
  
  #how to split a file path to two part (dir,filename)
  #_ like placeholder usage
  #unpack a tuple
  import os
  _, filename = os.path.split('/home/luciano/.ssh/idrsa.pub')
  print filename#idrsa.pub
  
  
  
subject: split a file using unpack a list