text: """
  @file
  @brief Helpers for module :epkg:`*py:os`.
  """
  import os
  
  
  def get_machine():
      """
      Returns the machine name.
  
      @return     machine name
  
      The method assumes environment variable ``COMPUTERNAME``,
      ``HOSTNAME`` or ``NAME`` is available.
      Otherwise, you should use module ``platform``.
      """
      name = os.environ.get("COMPUTERNAME",
                            os.environ.get("HOSTNAME",
                                           os.environ.get("NAME",
                                                          os.environ.get("TRAVIS_OS_NAME", None))))
      if name is None:
          raise ValueError("Unable to find machine name in {0}".format(
              ",".join(sorted(os.environ.keys()))))
      return name
  
  
  def get_user():
      """
      Returns the user name.
  
      @return     user name
  
      The method assumes environment variable ``USERNAME`` or ``USER``
      is available.
      """
      name = os.environ.get("USERNAME", os.environ.get(
          "USER", os.environ.get("CIRCLE_USERNAME", None)))
      if name is None:
          raise ValueError(  # pragma: no cover
              "Unable to find user name in {0}".format(
                  ",".join(sorted(os.environ.keys()))))
      return name
  