title: How to rename key and change value in json array
body: <p>I have a json which is:</p>
  
  <pre><code>abc = """
      {"entities":[
          {"entity":"sys-date",
           "location": [38,56],
           "value":"2007-01-01"}
      ]}
  """
  </code></pre>
  
  <p>I need the entity name <em>sys-date</em> to be replaced by name <em>Year</em> and value should be updated as 2007 (extract year part from date). </p>
  
  <p>The existing name <em>sys-date</em> and value <em>2007-01-01</em> should be deleted.</p>
  
  <p>How do I go about doing it in python 2x. Please help.</p>