@staticmethod
def _clean_city_name(city):
    """
        remove "area", "region" words from city names
        :param city: city name
        :return: clean city name
        """
    for word in [' Bay Area', ' area', ' Area', 'Greater ', 'und Umgebung',
        'e Região', 'Région de']:
        city = city.replace(word, '')
    mapping = {'zurich': 'Zürich'}
    return mapping.get(city.strip().lower(), city.strip())
