title: AttributeError: 'Timestamp' object has no attribute 'timestamp
body: <p>While converting a <code>panda</code> object to a timestamp, I am facing this strange issue.</p>
  
  <p>Train['date'] value is like <code>01/05/2014</code> which I am trying to convert into linuxtimestamp.</p>
  
  <p>My code:</p>
  
  <pre><code>Train = pd.read_csv("data.tsv", sep='\t') # use TAB as column separator
  Train['timestamp'] = pd.to_datetime(Train['date']).apply(lambda a: a.timestamp())
  </code></pre>
  
  <p>And I get this error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "socratis.py", line 11, in &lt;module&gt;
      Train['timestamp'] = pd.to_datetime(Train['date']).apply(lambda a: a.timestamp())
    File "/home/ubuntu/.local/lib/python2.7/site-packages/pandas/core/series.py", line 2220, in apply
      mapped = lib.map_infer(values, f, convert=convert_dtype)
    File "pandas/src/inference.pyx", line 1088, in pandas.lib.map_infer (pandas/lib.c:62658)
    File "socratis.py", line 11, in &lt;lambda&gt;
      Train['timestamp'] = pd.to_datetime(Train['date']).apply(lambda a: a.timestamp())
  AttributeError: 'Timestamp' object has no attribute 'timestamp'
  </code></pre>