@classmethod
def open(cls, path, mode):
    """
        Open a data file.  The base implementation of this function just
        opens and returns a standard python file object.

        Subclasses can override to either open files using different openers
        (like fitsio.FITS), or, for more specific data types, return an
        instance of the class itself to use as an intermediary for the file.

        """
    return open(path, mode)
