//清除空键值对
//自定义判断元素类型
function toType(obj)
{
  return ({}).toString.call(obj).match(/\s([a-zA-Z]+)/)[1].toLowerCase();
}
export const filter_param = (o) => {
  for(var key in o)
  {
    if(o[key]==null)
      delete o[key];
    if(toType(o[key])=="string")
    {
      o[key] = o[key].trim();
      if(o[key].length==0)
      {
        delete o[key];
      }
    }
  }
  return o;
}