title: Decode JSON in Bash using python mjson.tool
body: <p>I need to get a <code>key</code> from JSON in standard bash, and found the following:</p>
  
  <pre><code>echo '{"first_key": "value", "second_key": "value2"}' | python -mjson.tool | grep 'first_key'
  </code></pre>
  
  <p>But this returns:</p>
  
  <pre><code>"first_key": "value",
  </code></pre>
  
  <p>How can I just return <code>value</code>, i.e. not the key, and remove the quotes and comma.</p>
  
  <p>Thanks.</p>