title: How to remove timezone from a Timestamp column in a pandas dataframe
body: <p>I read <a href="https://stackoverflow.com/questions/40533647/pandas-change-timezone-for-forex-dataframe">Pandas change timezone for forex DataFrame</a> but I'd like to make the time column of my dataframe timezone naive for interoperability with an sqlite3 database.</p>
  
  <p>The data in my pandas dataframe is already converted to UTC data, but I do not want to have to maintain this UTC timezone information in the database.</p>
  
  <p>Given a sample of the data derived from other sources, it looks like this:</p>
  
  <pre><code>print(type(testdata))
  print(testdata)
  print(testdata.applymap(type))
  </code></pre>
  
  <p>gives:</p>
  
  <pre><code>&lt;class 'pandas.core.frame.DataFrame'&gt;
                          time  navd88_ft  station_id  new
  0  2018-03-07 01:31:02+00:00  -0.030332          13    5
  1  2018-03-07 01:21:02+00:00  -0.121653          13    5
  2  2018-03-07 01:26:02+00:00  -0.072945          13    5
  3  2018-03-07 01:16:02+00:00  -0.139917          13    5
  4  2018-03-07 01:11:02+00:00  -0.152085          13    5
                                       time        navd88_ft     station_id  \
  0  &lt;class 'pandas._libs.tslib.Timestamp'&gt;  &lt;class 'float'&gt;  &lt;class 'int'&gt;   
  1  &lt;class 'pandas._libs.tslib.Timestamp'&gt;  &lt;class 'float'&gt;  &lt;class 'int'&gt;   
  2  &lt;class 'pandas._libs.tslib.Timestamp'&gt;  &lt;class 'float'&gt;  &lt;class 'int'&gt;   
  3  &lt;class 'pandas._libs.tslib.Timestamp'&gt;  &lt;class 'float'&gt;  &lt;class 'int'&gt;   
  4  &lt;class 'pandas._libs.tslib.Timestamp'&gt;  &lt;class 'float'&gt;  &lt;class 'int'&gt;   
  
               new  
  0  &lt;class 'int'&gt;  
  1  &lt;class 'int'&gt;  
  2  &lt;class 'int'&gt;  
  3  &lt;class 'int'&gt;  
  4  &lt;class 'int'&gt;  
  </code></pre>
  
  <p>but </p>
  
  <pre><code>newstamp = testdata['time'].tz_convert(None)
  </code></pre>
  
  <p>gives an eventual error:</p>
  
  <pre><code>TypeError: index is not a valid DatetimeIndex or PeriodIndex
  </code></pre>
  
  <p>What do I do to replace the column with a timezone naive timestamp?</p>