title: How to find k biggest numbers from a list of n numbers assuming n > k
body: <p>I am looking for some code in Python which could return <code>k</code> largest numbers from an unsorted list of <code>n</code> numbers. First I thought to do this by sorting the list first, but this might turn out to be very bulky. </p>
  
  <p>For example the list from which I want to find <code>k</code> largest number be <code>list1</code></p>
  
  <pre><code>&gt; list1 = [0.5, 0.7, 0.3, 0.3, 0.3, 0.4, 0.5]
  </code></pre>
  
  <p>Here <code>n = 7</code> and if <code>k = 3</code>, that is if I want to find 3 largest numbers from a list of 7 numbers then output should be <code>0.5, 0.7, 0.5</code></p>
  
  <p>How can this be done?</p>