title: Split string by position not character
body: <p>We know that <code>anchors</code>, <code>word boundaries</code>, and <code>lookaround</code> match at a position, rather than matching a character.<br>
  Is it possible to split a string by one of the preceding ways with regex (specifically in python)?</p>
  
  <p>For example consider the following string:</p>
  
  <pre><code>"ThisisAtestForchEck,Match IngwithPosition." 
  </code></pre>
  
  <p>So i want the following result (the sub-strings that start with uppercase letter but not precede by space ):</p>
  
  <pre><code>['Thisis', 'Atest', 'Forch' ,'Eck,' ,'Match Ingwith' ,'Position.']
  </code></pre>
  
  <p>If i split with grouping i get:</p>
  
  <pre><code>&gt;&gt;&gt; re.split(r'([A-Z])',s)
  ['', 'T', 'hisis', 'A', 'test', 'F', 'orch', 'E', 'ck,', 'M', 'atchingwith', 'P', 'osition.']
  </code></pre>
  
  <p>And this is the result with look-around :</p>
  
  <pre><code>&gt;&gt;&gt; re.split(r'(?&lt;=[A-Z])',s)
  ['ThisisAtestForchEck,MatchingwithPosition.']
  &gt;&gt;&gt; re.split(r'((?&lt;=[A-Z]))',s)
  ['ThisisAtestForchEck,MatchingwithPosition.']
  &gt;&gt;&gt; re.split(r'((?&lt;=[A-Z])?)',s)
  ['ThisisAtestForchEck,MatchingwithPosition.']
  </code></pre>
  
  <p>Note that if i want to split by sub-strings that start with uppercase and are  preceded by a space, e.g.:</p>
  
  <pre><code>['Thisis', 'Atest', 'Forch' ,'Eck,' ,'Match ', Ingwith' ,'Position.']
  </code></pre>
  
  <p>I can use <code>re.findall</code>, viz.: </p>
  
  <pre><code>&gt;&gt;&gt; re.findall(r'([A-Z][^A-Z]*)',s)
  ['Thisis', 'Atest', 'Forch', 'Eck,', 'Match ', 'Ingwith', 'Position.']
  </code></pre>
  
  <p>But what about the first example: is it possible to solve it with <code>re.findall</code>? </p>