title: Python regex : adding space after comma only if not followed by a number
body: <p>I want to add spaces after and before comma's in a string only if the following character isn't a number (9-0).  I tried the following code: </p>
  
  <pre><code>newLine = re.sub(r'([,]+[^0-9])', r' \1 ', newLine)
  </code></pre>
  
  <p>But it seems like the <code>\1</code> is taking the 2 matching characters and not just the comma. 
  Example:</p>
  
  <pre><code>&gt;&gt;&gt; newLine = "abc,abc"
  &gt;&gt;&gt; newLine = re.sub(r'([,]+[^0-9])', r' \1 ', newLine)
  "abc ,a bc"
  </code></pre>
  
  <p>Expected Output:</p>
  
  <pre><code>"abc , abc"
  </code></pre>
  
  <p>How can I tell the <code>sub</code> to take only the 'comma' ?  </p>