新的scraping在这里。我的问题是相当直接的，我试图从跨度类“DFlfde SwHCTb”得到值data-value。然而，我得到未定义的返回。我在下面的代码中犯了什么错误？

const axios = require('axios');
const cheerio = require('cheerio');

const url = 'https://www.google.com/search?q=sgd+myr&spell=1&sa=X&ved=2ahUKEwiStvfn5ozoAhVWH7cAHQJZCpwQBSgAegQIDRAm&biw=960&bih=746';

axios(url)
  .then(response => {
    const html = response.data;
    const $ = cheerio.load(html)
    console.log($('span.DFlfde.SwHCTb').attr('data-value'));
  })
  .catch(console.error);

仅打印console.log($('span.DFlfde.SwHCTb'));时

initialize {
  options: {
    withDomLvl1: true,
    normalizeWhitespace: false,
    xml: false,
    decodeEntities: true
  },
  _root: initialize {
    '0': {
      type: 'root',
      name: 'root',
      namespace: 'http://www.w3.org/1999/xhtml',
      attribs: [Object: null prototype] {},
      'x-attribsNamespace': [Object: null prototype] {},
      'x-attribsPrefix': [Object: null prototype] {},
      children: [Array],
      parent: null,
      prev: null,
      next: null
    },
    options: {
      withDomLvl1: true,
      normalizeWhitespace: false,
      xml: false,
      decodeEntities: true
    },
    length: 1,
    _root: [Circular]
  },
  length: 0,
  prevObject: initialize {
    '0': {
      type: 'root',
      name: 'root',
      namespace: 'http://www.w3.org/1999/xhtml',
      attribs: [Object: null prototype] {},
      'x-attribsNamespace': [Object: null prototype] {},
      'x-attribsPrefix': [Object: null prototype] {},
      children: [Array],
      parent: null,
      prev: null,
      next: null
    },
    options: {
      withDomLvl1: true,
      normalizeWhitespace: false,
      xml: false,
      decodeEntities: true
    },
    length: 1,
    _root: [Circular]
  }
}