title: Python web-scraping of Expedia, how to find right keyword
body: <p>I am learning about Python scraper. I take an simple exercise about find the cheap ticket in Expedia. Now, I meet some problems about how to find the right selector or accurate keyword. I use functions like select() and find(). I took too many tests about them but I still did it successfully. I always get empty list. How can I find the right selector or keywork in a better method?
  There is a part of my code. In it, I try to find the location of the input of Place: Flying from and the button Roundtrip.  </p>
  
  <pre><code>    headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36'}
      url="https://www.expedia.com/Flights?langid=1033&amp;semcid=US.MULTILOBF.GOOGLE.GT-c-EN.FLIGHT&amp;semdtl=a1355852835.b125535175035.r1.g1kwd-12197061.i1.d1280328929841.e1c.j120181.k1.f11t1.n1.l1g.h1e.m1&amp;gclid=CjwKCAiAws7uBRAkEiwAMlbZjjBMg2bBBbp59C6tXeHf-4sXVvc4ya7EflIKQGsaFgENRP_SbaNQrRoCsUoQAvD_BwE"  
      address_page1 = requests.get(url, headers=headers).content
      soup = BeautifulSoup(address_page1,'html.parser')
  
      find = soup.find_all(id='flight-origin-flp-airport_code')
      print(find)
  
      select1 = soup.select('#flight-origin-flp-airport_code')
      print(select1)
  
      select2 = soup.select('#gcw-flights-form-flp &gt; div.cols-nested.ab25184-location &gt; div &gt; div &gt; div.input-btn-group')
      print(select2)
  </code></pre>