old_contents: #!/usr/bin/env python
  import sys
  
  with open(sys.argv[1]) as f:
    str = f.read().decode('unicode_escape')
    print str.encode('utf-8')
  
new_contents: #!/usr/bin/python
  import sys
  
  if len(sys.argv) < 2:
      print "where is input escaped-unicode file?"
      exit(1)
  
  with open(sys.argv[1]) as f:
      str = f.read().decode('unicode_escape')
      print str.encode('utf-8')
  
subject: add some information to escaped-unicode converting script.