def dict_to_ul(data, result=''):
    try:
        if not isinstance(data, dict):
            return data 
        result += "<ul>"
        for key in data.keys():
            result += "<li>"
            value = data[key]
            if isinstance(value, dict):
                result += "%s: %s" % (key, dict_to_ul(value))
            else:
                result += "%s: %s" % (key, value) 
            result += "</li>"
        result += "</ul>"
        return result
    except Exception:
        return ''