title: How to rename a pandas dataframe in a memory-efficient way (without creating a copy)?
body: <p>I want to rename a pandas dataframe <code>df_old</code> into <code>df_new</code>.</p>
  
  <p>Since <a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.rename.html" rel="nofollow noreferrer">df.rename</a> only seems to be designed for single series/columns within a given dataframe, I use the following approach in the moment:</p>
  
  <pre><code>df_new = df_old
  del df_old
  </code></pre>
  
  <p>However, this is not memory efficient at all, since it creates a copy of <code>df_old</code>.</p>
  
  <p><strong>How to rename a pandas dataframe in a more memory-efficient way, similar to <code>inplace = True</code>?</strong></p>