code: def get_config_file():
      
      import os
      from os.path import abspath, expanduser, join, exists
  
      __lib_name = get_library_name()
  
      assert __lib_name in ["sframe", "turicreate"]
  
      __default_config_path = join(expanduser("~"), ".%s" % __lib_name, "config")
  
      if "TURI_CONFIG_FILE" in os.environ:
          __default_config_path = abspath(expanduser(os.environ["TURI_CONFIG_FILE"]))
  
          if not exists(__default_config_path):
              print(("WARNING: Config file specified in environment variable "
                     "'TURI_CONFIG_FILE' as "
                     "'%s', but this path does not exist.") % __default_config_path)
  
      return __default_config_path
docs: Returns the file name of the config file from which the environment
      variables are written.