old_contents: # encoding: utf-8
  
  """
  .. codeauthor:: Tsuyoshi Hombashi <gogogo.vm@gmail.com>
  """
  
  from __future__ import absolute_import
  import random
  import string
  
  
  alphanum_char_list = [x for x in string.digits + string.ascii_letters]
  
  
  INVALID_PATH_CHARS = ["\0"]
  INVALID_FILENAME_CHARS = ["/"]
  INVALID_WIN_PATH_CHARS = [
      ":", "*", "?", '"', "<", ">", "|",
  ] + INVALID_PATH_CHARS
  INVALID_WIN_FILENAME_CHARS = (
      INVALID_WIN_PATH_CHARS +
      INVALID_FILENAME_CHARS +
      ["\\"]
  )
  
  VALID_FILENAME_CHARS = [
      "!", "#", "$", '&', "'", "_",
      "=", "~", "^", "@", "`", "[", "]", "+", "-", ";", "{", "}",
      ",", ".", "(", ")", "%",
  ]
  VALID_PATH_CHARS = VALID_FILENAME_CHARS + ["/"]
  
  INVALID_VAR_CHARS = INVALID_WIN_FILENAME_CHARS + [
      "!", "#", "$", '&', "'",
      "=", "~", "^", "@", "`", "[", "]", "+", "-", ";", "{", "}",
      ",", ".", "(", ")", "%",
      " ", "\t", "\n", "\r", "\f", "\v",
  ]
  
  
  def make_random_str(length, char_list=alphanum_char_list):
      return "".join([random.choice(char_list) for _i in range(length)])
  
new_contents: # encoding: utf-8
  
  """
  .. codeauthor:: Tsuyoshi Hombashi <gogogo.vm@gmail.com>
  """
  
  from __future__ import absolute_import
  from __future__ import unicode_literals
  import random
  import string
  
  
  alphanum_char_list = [x for x in string.digits + string.ascii_letters]
  
  
  INVALID_PATH_CHARS = ["\0"]
  INVALID_FILENAME_CHARS = ["/"]
  INVALID_WIN_PATH_CHARS = [
      ":", "*", "?", '"', "<", ">", "|",
  ] + INVALID_PATH_CHARS
  INVALID_WIN_FILENAME_CHARS = (
      INVALID_WIN_PATH_CHARS +
      INVALID_FILENAME_CHARS +
      ["\\"]
  )
  
  VALID_FILENAME_CHARS = [
      "!", "#", "$", '&', "'", "_",
      "=", "~", "^", "@", "`", "[", "]", "+", "-", ";", "{", "}",
      ",", ".", "(", ")", "%",
  ]
  VALID_PATH_CHARS = VALID_FILENAME_CHARS + ["/"]
  
  INVALID_VAR_CHARS = INVALID_WIN_FILENAME_CHARS + [
      "!", "#", "$", '&', "'",
      "=", "~", "^", "@", "`", "[", "]", "+", "-", ";", "{", "}",
      ",", ".", "(", ")", "%",
      " ", "\t", "\n", "\r", "\f", "\v",
  ]
  
  
  def make_random_str(length, char_list=alphanum_char_list):
      return "".join([random.choice(char_list) for _i in range(length)])
  
subject: Add unicode_literals import