def split_by_equals(word, unused_lines, iline):
    """
    splits 'x = 42'
    into 'x' and '42'
    """
    if '=' not in word:
        msg = 'line %i: %r cannot be split by an equals sign (=)' % (iline, word)
        raise RuntimeError(msg)
    word_out, value = word.split('=')
    return word_out, value