title: Can re.findall() return None?
body: <p>The <a href="https://docs.python.org/2/library/re.html#re.findall" rel="nofollow noreferrer">documentation</a> only says that is returns "a list". I would assume that when it finds no matches it returns an empty list (but not <code>None</code>) and it never returns a <code>None</code>. But I'm not sure. Can anyone confirm?</p>
  
  <p>Also, is there a way for me to check that in the future on my own for other functions (e.g. <code>ElementTree.findall()</code>)? Can I just assume that whenever the docs say "a list" it will behave the same way?</p>