title: make a truly deep copy of a pandas Series
body: <p>I have a <code>pd.Series</code> with each cell being a list.
  I want to make a deep copy of it, however it seems like <a href="https://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.copy.html" rel="nofollow noreferrer"><code>pd.Series.copy</code></a> only creates a shallow copy of the values (even though the <code>deep</code> arg is <code>True</code> be default).</p>
  
  <p>example</p>
  
  <pre><code>import pandas as pd
  
  sr = pd.Series([list(range(3)), list(range(3))])
  sr_c = sr.copy()
  sr[0].append(4)
  </code></pre>
  
  <p>the copied <code>pd.Series</code> <code>sr_c</code> is being transformed to </p>
  
  <pre><code>0   [0, 1, 2, 4]
  1   [0, 1, 2]
  </code></pre>
  
  <p>I did this and it worked:</p>
  
  <pre><code>from copy import deepcopy
  sr_c = sr_c.apply(deepcopy)
  </code></pre>
  
  <p>however this seems like a hack, is there a better way to do it ? </p>