title: writing to a json file from python
body: <p>how do i edit/change a particular field in a json file using python code:</p>
  
  <pre><code>{
     "EZMessage":{
        "action":"account.cash",
        "data":{
           "authToken":"123456",
           "account":"#ACCOUNTID#",
           "portfolio":"true",
           "historical":"true"
        }
     }
  }
  </code></pre>
  
  <p>in this json code, i want to replace 123456 with 789123</p>
  
  <p>string replace only works if i know what is written there. in my code, i would only know what to write, and the identifier "authToken". Is there a way to overwrite the 123456 by identifying that it is the value of "authToken" ?</p>
  
  <p>thanks,</p>
  
  <p>RS</p>