객체의 문자열 반환

  let params = {
    open_raffle_id: '{{ open_raffle.id }}',
  	type: 'BUY',
    ordering: 'option,site,-id',
  }
  
     params = Object.keys(params)
     .map(function (key) {
       return '' + key + '=' + params[key];
     })
     .join('&');

https://stackoverflow.com/questions/32464948/mapping-object-to-key-value-string-in-one-line