title: Write to specific objects in json. Python
body: <p>I want to create a program that loads a json file, reads it and then adds a 
  object to a list.</p>
  
  <pre><code>import json
  
  newo = {
      "balance": "1234",
      "time": "forever"
  }
  
  with open("json.json", "r") as f:
      data = json.load(f)
  
  with open("json.json", "w") as f:
      json.dump(newo, f)
  </code></pre>
  
  <p>This is the python file I have been using.</p>
  
  <pre><code>{ 
      "cointiply": [
          {
              "balance" : "242537",
              "time": "28.05.2019"
          },
          {
              "balance": "246362",
              "time": "29.05.2019"
          }
      ]
  }
  </code></pre>
  
  <p>And that's the json file.</p>
  
  <p>I now want the newo list to be inserted into the json list "cointiply".</p>
  
  <p>Any idea how that could be done?
  Because right now the "newo" list is deleting every think in the json file and then just inserted like the file would have been empty.</p>