title: How to delete all data of a json document except the key/value I want
body: <p>So I have a rather big document with entries like: </p>
  
  <pre><code>"kff126d":"Infinity"
  </code></pre>
  
  <p>And others like: </p>
  
  <pre><code>"kff126d":"0.03702955"
  </code></pre>
  
  <p>And a few dozens of other keys like kff126e and so on, and I would like to remove everything that isn't the one key I want to keep, and whatever value is inside the second set of quotation marks, so I can take a look at abnormal values.</p>
  
  <p>Could someone help me out? I've tried looking arround but it's quite complex compared to the few things I've done with regex before this. Thanks in advance.</p>