```
def get_next_target(page):

    start_link = page.find('<a href="')

    if start_link == -1:
        return None, 0

    end_link = page.find('">', start_link)
    url = page[start_link + 9 : end_link]
    return url, end_link

def print_all_links(page):

  url = True
  while url != None:
    url, endpos = get_next_target(page)
    if url:
        print url   #True
        page = page[endpos : ]
    else: 
        break

page = '<div id="top_bin"><div id="top_content" class="width960"><div class="udacity float-left"><a href="http://udacity.com"><a href="http://udacity.com"><a href="http://udacity.com"><a href="http://udacity.com">'

print print_all_links(page)

```

My question here is when I print out the result it will print four URLs and that what is expected, but when I set the while to `while url == True:` it will print out one URL only, so what is the reason? Isn't != None equals to ==True