def get_html_lines(html_files):
    """
    Parameters
    ----------
    html_files: list of files
    list of html files created by get_html_files()

    Return
    ------------
    list of strs
    all lines from html_files in one list
    """
    html_lines = []
    for file in html_files:
        lines = file.readlines()
        html_lines = html_lines + lines
    return html_lines