title: How to get all keys from a value for a dict of lists?
body: <p>I have a dictionary in a format like this</p>
  
  <pre><code>d = {
      "Fruit_1" : ["mango", "apple"],
      "Fruit_2" : ["apple"],
      "Fruit_3" : ["mango", "banana", "apple", "kiwi", "orange"]
  }
  </code></pre>
  
  <p>I'm passing a value as "mango" and I want to get all corresponding keys where only mango occurs. I am not able to get corresponding keys where ever value occurs. </p>