input: Write a function to build a web scraper in Python that collects all the links from a given website URL. The function should return a list of all the href attributes found in anchor tags on the webpage. If the URL is invalid or the webpage contains no links, the function should return an empty list.
  
  assert scrape_links("http://www.example.com/") == ['http://www.example.com/about', 'http://www.example.com/contact']
  assert scrape_links("http://www.invalidurl.com/") == []
  assert scrape_links("http://www.nolinkspage.com/") == []
  assert scrape_links("") == []
output: import requests
  from bs4 import BeautifulSoup
  
  def scrape_links(url):
      try:
          response = requests.get(url)
          response.raise_for_status()
      except:
          return []
      
      soup = BeautifulSoup(response.text, 'html.parser')
      links = [a['href'] for a in soup.find_all('a', href=True)]
      
      return links