How do I release memory used by a pandas dataframe?
<p>I have a really large csv file that I opened in pandas as follows....</p>

<pre><code>import pandas
df = pandas.read_csv('large_txt_file.txt')
</code></pre>

<p>Once I do this my memory usage increases by 2GB, which is expected because this file contains millions of rows.  My problem comes when I need to release this memory.  I ran....</p>

<pre><code>del df
</code></pre>

<p>However, my memory usage did not drop.  Is this the wrong approach to release memory used by a pandas data frame?  If it is, what is the proper way? </p>