def print_to_screen(txt=None):
    """Method to print output to standard out.

    This method is included to ensure that output from pyretis to the
    screen is written out in a uniform way across the library and
    application(s).

    Parameters
    ----------
    txt : string
        The text to write to the screen
    """
    if txt is None:
        print()
    else:
        out = '# {}'.format(txt)
        out = out.replace('\n', '\n# ')
        print(out)
