title: finditer with re.DOTALL starts analysis from span=(16,17). Why?
body: <p>I'm trying to dismember a text file to sections with findall sort or action.
  I need backreferencing so I opt for finditer.
  Since I'm processing a text file w multiple lines - I need re.DOTALL. It works fine as long as the match doesn't start in first 16 characters.
  The (over)simplified problem example:</p>
  <pre><code>r=re.compile(r'[0-9]')
  [print(i) for i in r.finditer('01234567890123456789',re.DOTALL)]
  </code></pre>
  <p>The output is:</p>
  <pre><code>&lt;re.Match object; span=(16, 17), match='6'&gt;
  &lt;re.Match object; span=(17, 18), match='7'&gt;
  &lt;re.Match object; span=(18, 19), match='8'&gt;
  &lt;re.Match object; span=(19, 20), match='9'&gt;
  [None, None, None, None]
  </code></pre>
  <p>I expect 20 matches and not 4.
  I guess that I could achieve my objective with re.MULTILINE but I'd like preserve my faith in python re functions and/or my understanding of them.
  Please advice.</p>
  <p>KonradP</p>