Slicing a DataFrame
<p>Consider the DataFrame <code>data</code>:</p>

<pre><code>                 one  two  three  four
Ohio      2013-01-01    1      2     3
Colorado  2014-01-05    5      6     7
Utah      2015-05-06    9     10    11
New York  2016-10-11   13     14    15
</code></pre>

<p>I'd like to extract the row using only the criterion that the year is a given year, e.g., something like <code>data['one'][:][0:4] == '2013'</code>.  But the command <code>data['one'][:][0:4]</code> returns</p>

<pre><code>Ohio        2013-01-01
Colorado    2014-01-05
Utah        2015-05-06
New York    2016-10-11
Name: one, dtype: object
</code></pre>

<p>I thought this is the right thing to do because the command <code>data['one'][0][0:4]</code> returns</p>

<pre><code>'2013'
</code></pre>

<p>Why the difference, and what's the correct way to do this?</p>