import re


def extract_options(pattern):
    """Extracts 'options' of a url pattern given a pattern
    returns list of lists

    Example:

    input: '^home/city
      (-(?P<city_name>bristol|bath|cardiff|swindon|oxford|reading))?$'

    output: [[bristol, bath, cardiff, swindon, oxford, reading]]
    """
    result = [
        match.group(1).split('|')
        for match
        in re.finditer(r'\(\?P<.+?>(.+?)\)', pattern)
    ]

    return result