code: def find_in_data_path(filename):
      
      for path in config.data_path:
          path = os.path.expanduser(os.path.expandvars(path))
          file_path = os.path.join(path, filename)
          if os.path.isfile(file_path):
              return file_path
      raise IOError("{} not found in Fuel's data path".format(filename))
docs: Searches for a file within Fuel's data path.
  
      This function loops over all paths defined in Fuel's data path and
      returns the first path in which the file is found.
  
      Parameters
      ----------
      filename : str
          Name of the file to find.
  
      Returns
      -------
      file_path : str
          Path to the first file matching `filename` found in Fuel's
          data path.
  
      Raises
      ------
      IOError
          If the file doesn't appear in Fuel's data path.