import urllib2

def get_all_links(page):
  #extract all links from the html page
  
def get_page(link):
  #get the html page
  

def addTasks(tasks, newTasks):
  for task in newTasks:
    tasks.append(task)


def crawl(seed)
{
  tasks = [seed]
  visited = []
  while(tasks):
    link = tasks.pop();
    if link not in visited:
      page = get_page(link)
      links = get_all_links(page)
      addTasks(tasks, links)
      visited.append(link)
      #do something with the page...
      #maybe store in DB
}