title: removing numbers that immediately precede words
body: <p>Trying to get rid of the numbers in the below sentence. Can anyone help?
  Thanks</p>
  
  <pre><code>x="genes1,2,4,5... activation5–10... modifications11–14... previously15."
  </code></pre>
  
  <p>My attempt:</p>
  
  <pre><code>x=re.sub(r'([a-z]),([1-100])', r'\1\2', x)
  </code></pre>
  
  <p>DESIRED OUTPUT:</p>
  
  <pre><code> "genes... activation... modifications... previously".
  </code></pre>