def cleanup_string(string):
    """
    >>> cleanup_string(u', Road - ')
    u'road'
    >>> cleanup_string(u',Lighting - ')
    u'lighting'
    >>> cleanup_string(u', Length - ')
    u'length'
    >>> cleanup_string(None)
    ''
    >>> cleanup_string(' LIT ..')
    'lit'
    >>> cleanup_string('poor.')
    'poor'
    """
    if string is None: return ''
    string = string.replace(',', '')
    string = string.replace('.', '')    
    string = string.replace(' ', '')
    string = string.replace('-', '')
    string = string.lower()
    return string