title: PowerBI Regular Expression Using M or Python
body: <p>I've never used Python inside of PowerBI before, but I have used Python. I'm happy with a Python or M language solution though.</p>
  <p>Let's say I have a column that looks like this:</p>
  <pre><code>EntryTime
  12:00:00 - 01:10:00
  01:00:30 - 05:10:50
  2020-11-03 R
  2010-03-31 R
  2020-04-01 R
  </code></pre>
  <p>I want to replace all values that contain this format, and is case insensitive, with <code>NULL</code> values:</p>
  <pre><code>yyyy-MM-dd( )+[R] 
  </code></pre>
  <p>How can I implement this in PowerBI using either M or Python? Please be very specific as I have not used Python inside of PowerBI before.</p>