title: How to add a fixed number to the integer part of a filename?
body: <p>Using Python, I need to add 100 to the integer part of some filenames to rename the files. The files look like this: <code>0000000_6dee7e249cf3.log</code>  where  <code>6dee7e249cf3</code> is a random number. At the end I should have:</p>
  
  <pre><code>0000000_6dee7e249cf3.log should change to 0000100_6dee7e249cf3.log
  0000001_12b2bb88d493.log should change to 0000101_12b2bb88d493.log
  etc, etc…
  </code></pre>
  
  <p>I can print the initial files using:</p>
  
  <pre><code>initial: glob('{0:07d}_*[a-z]*'.format(NUM))
  </code></pre>
  
  <p>but the final files returns an empty list:</p>
  
  <pre><code>final: glob('{0:07d}_*[a-z]*'.format(NUM+100))
  </code></pre>
  
  <p>Moreover, I cannot not rename initial to final using os.rename because it can not read the list created using the globe function.</p>