title: how to open some specific files using python
body: <p>I have a couple of files named as <code>yyyymmdd-hhmmss.csv.gz</code>. Now I want to open each day's first file from 02am, do some process, one by one.</p>
  
  <p>My files are: </p>
  
  <pre><code>...
  20120706-015923.txt
  20120706-015934.txt 
  20120706-020008.txt
  20120706-020030.txt
  ...
  20120707-015934.txt
  20120707-020005.txt
  20120707-020015.txt
  ...
  </code></pre>
  
  <p>So I want to go through the file name in this folder first, to find <code>20120706-020008.txt</code> which is the first file from the 02am that day, then I had a script to read all the lines and do some process. My problem is, how to tell this script to find these files?
  <code>20120706-020008.txt</code>, <code>20120707-020015.txt</code>, <code>20120708-02</code>....</p>