util.py 文件源码

def DoesUrlExist(url):
  """Determines whether a resource exists at the given URL.

  Args:
    url: URL to be verified.

  Returns:
    True if url exists, otherwise False.
  """
  parsed = urlparse.urlparse(url)
  try:
    conn = httplib.HTTPConnection(parsed.netloc)
    conn.request('HEAD', parsed.path)
    response = conn.getresponse()
  except (socket.gaierror, socket.error):
    return False
  finally:
    conn.close()
  # Follow both permanent (301) and temporary (302) redirects.
  if response.status == 302 or response.status == 301:
    return DoesUrlExist(response.getheader('location'))
  return response.status == 200