title: Separate number/letter tokens in Python
body: <p>I'm using <code>re.split()</code> to separate a string into tokens. Currently the pattern I'm using as the argument is <code>[^\dA-Za-z]</code>, which retrieves alphanumeric tokens from the string. </p>
  
  <p>However, what I need is to also split tokens that have both numbers and letters into tokens with only one or the other, eg.</p>
  
  <pre><code>re.split(pattern, "my t0kens")
  </code></pre>
  
  <p>would return <code>["my", "t", "0", "kens"]</code>.</p>
  
  <p>I'm guessing I might need to use lookahead/lookbehind, but I'm not sure if that's actually necessary or if there's a better way to do it.</p>