def get_regions(market):
    """
    Get a comma-separated list of regions the Market's serves
    """

    region_list = []
    for country in market.countries_served.all():
        if str(country.region) not in region_list:
            region_list.append(str(country.region))

    region_list.sort(key=lambda region: region)
    return ", ".join(region_list)