推物体给我推没有功能

一直在尝试调试几个小时，但是我无法理解。

  ratings = {
      "hotel_a": "2.8",
  };

   ///ratings.push ( { hotel_b : 3.2} );
  console.log(ratings);

   // total number of stars
  const starTotal = 5;

  for (const rating in ratings) {
      const starPercentage = (ratings[rating] / starTotal) * 100;
      const starPercentageRounded = `${(Math.round(starPercentage / 10) * 10)}%`;
      document.querySelector(`.${rating}.stars - inner`).style.width = starPercentageRounded;
  }

它给了我ratings.push不是函数。