input: Write a function to scrape photos and captions from a given website URL using BeautifulSoup and requests. It should extract and print the source URLs of the photos along with their captions if available. If the website does not have captions for some photos, it should print "No caption".
  
  from bs4 import BeautifulSoup
  import requests
  
  def scrape_photos_captions(url):
      req = requests.get(url)
      html = req.text
      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_captions('https://example.com/webpage') is None
output: 
  def scrape_photos_captions(url):
      req = requests.get(url)
      html = req.text
      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')
  