title: How to filter files (with known type) from os.walk?
body: <p>I have list from <code>os.walk</code>. But I want to exclude some directories and files. I know how to do it with directories:</p>
  
  <pre><code>for root, dirs, files in os.walk('C:/My_files/test'):
      if "Update" in dirs:
          dirs.remove("Update")
  </code></pre>
  
  <p>But how can I do it with files, which type I know. because this doesn't work:</p>
  
  <pre><code>if "*.dat" in files:
      files.remove("*.dat")
  </code></pre>