input: Write a function to scrape photos and captions from a given website. The function should take a URL as input, retrieve the HTML content, parse it using BeautifulSoup, and print the source of each photo along with its caption if available. If no caption is found, it should print "No caption".
  
  def scrape_photos_and_captions(url):
      from bs4 import BeautifulSoup
      import requests
  
      # Get the HTML source code
      req = requests.get(url)
      html = req.text
  
      # Parse HTML source and extract photo and caption
      soup = BeautifulSoup(html, features='lxml')
      image_divs = soup.find_all('div', {'class': 'image-gallery__image'})
  
      for image_div in image_divs:
          figure = image_div.find('figure')
          src = figure.find('img')['src']
          caption = figure.find('figcaption')
          print('Photo: ', src)
          if caption:
              print('Caption: ', caption.text)
          else:
              print('No caption')
          print('\n')
  
  assert scrape_photos_and_captions('https://example.com/sample_webpage')==None
output: def scrape_photos_and_captions(url):
      from bs4 import BeautifulSoup
      import requests
  
      # Get the HTML source code
      req = requests.get(url)
      html = req.text
  
      # Parse HTML source and extract photo and caption
      soup = BeautifulSoup(html, features='lxml')
      image_divs = soup.find_all('div', {'class': 'image-gallery__image'})
  
      for image_div in image_divs:
          figure = image_div.find('figure')
          src = figure.find('img')['src']
          caption = figure.find('figcaption')
          print('Photo: ', src)
          if caption:
              print('Caption: ', caption.text)
          else:
              print('No caption')
          print('\n')