title: TypeError: 'map' object is not subscriptable
body: <p>I am trying to implement BCH codes in Pyton 3.7.
  I am getting an error in the map function .
  initially the code written was </p>
  
  <pre><code>Dvec = map(int, bin(D)[2:] )[::-1]
  </code></pre>
  
  <p>I tried using list as</p>
  
  <pre><code>Dvec = list(map(int, bin(D)[2:] )[::-1])
  </code></pre>
  
  <p>Still the error persists as</p>
  
  <pre><code>TypeError: 'map' object is not subscriptable.
  </code></pre>
  
  <p>How to use this function now?</p>