title: Append to each dictionary within a list
body: <p>I have a list of dictionary objects:</p>
  
  <pre><code>[{u'ID': 46757,
    u'currentenddate': u'09/30/2016',
    u'name': u'Project A',
    u'projstartdate': u'05/01/2016'},
   {u'ID': 46625,
    u'currentenddate': u'07/15/2016',
    u'name': u'Project B',
    u'projstartdate': u'05/02/2016'},
   {u'ID': 47100,
    u'currentenddate': u'08/02/2016',
    u'name': u'Project C',
    u'projstartdate': u'06/01/2016'}]
  </code></pre>
  
  <p>and I would like to append to ALL dictionary items a new field <code>client_id</code>, resulting in:</p>
  
  <pre><code>[{u'ID': 46757,
    u'currentenddate': u'09/30/2016',
    u'name': u'Project A',
    u'projstartdate': u'05/01/2016'},
    u'client_id': u'12398'},
   {u'ID': 46625,
    u'currentenddate': u'07/15/2016',
    u'name': u'Project B',
    u'projstartdate': u'05/02/2016'},
    u'client_id': u'12398'},
   {u'ID': 47100,
    u'currentenddate': u'08/02/2016',
    u'name': u'Project C',
    u'projstartdate': u'06/01/2016'}
    u'client_id': u'12398'}]
  </code></pre>
  
  <p><code>client_id</code> will remain the same for all dictionary items.  I know I can achieve the outcome using a <code>for</code> loop coupled with <code>dict['client_id'] = id</code> but the code is no longer vectorized.  Is there a pythonic way to append to each dict item within the list?</p>
  
  <hr>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>Thanks for the lively conversation about list comprehensions versus <code>for</code> loops.  I'll test both methods and use the faster of the two for my situation.  Also, going forward, I'll explicitly define what I mean by 'vectorized' and 'pythonic' in my questions, so we're all on the same page (thanks, @Adam Smith).</p>