@classmethod
def dicts_to_url(cls, dic, url=None):
    """
        将字典转换成get的url参数部分
        :param dic:
        :return:
        """
    parastring = ''
    for key, value in dic.items():
        parastring += str(key) + '=' + str(value) + '&'
    parastring = parastring[:-1]
    if url:
        return url + '?' + parastring
    return parastring
