title: DictReader get a value when a column # and row # are known
body: <p>I am given a csv file that looks something like this</p>
  
  <pre><code>ID, name, age, city
  1, Andy, 25, Ann Arbor
  2, Bella, 40, Los Angeles
  3, Cathy, 13, Eureka
  ...
  ...
  </code></pre>
  
  <p>If I want to get the <code>city</code> of <code>ID</code>=3, which would be Eureka for this example. Is there a way to do this efficiently instead of iterating each row? My php code will be executing this python script each time to get the value, and I feel like being very inefficient to loop through the csv file every time. </p>