def format_header(header, tchar):
    """Given a string and title char return a reStructuredText style section
    header.

    :param header: The header text to format
    :param tchar: The character to use.

    :type header: str
    :type tchar: str

    :rtype: str
    :returns: The formatted title.
    """
    return header + '\n' + tchar * len(header)
