def locale_from_currency_code(dx_code):
    """
    This is a (temporary) hardcoded mapping between currency_list.json in nucleus and standard
    locale string useful for further formatting

    :param dx_code: An id of nucleus/commons/pricing_models/currency_list.json collection
    :return: standardised locale, eg 'en_US'; None when no mapping found
    """
    currency_locale_map = {0: 'en_US', 1: 'en_GB'}
    return currency_locale_map[dx_code] if dx_code in currency_locale_map else None