title: pandas different column names same data
body: <p>How do i use the same data storage and change only the columns.</p>
  
  <p>If i do something like this:</p>
  
  <pre><code>In [30]: import pandas as pd
  
  In [31]: import numpy as np
  
  In [32]: df = pd.DataFrame(np.zeros((2,2)))
  
  In [33]: df_new = pd.DataFrame(df)
  
  In [34]: df[0][0]=5
  
  In [35]: df_new
  Out[35]:
       0    1
  0  5.0  0.0
  1  0.0  0.0
  
  In [36]: df_new.columns=["a", "b"]
  In [37]: df_new.columns
  Out[37]: Index(['a', 'b'], dtype='object')
  
  In [38]: df.columns
  Out[38]: Index(['a', 'b'], dtype='object')
  </code></pre>
  
  <p>Changes columns for both dataframes. Using dataframe <code>rename</code> inplace leads to columns being changed for both dataframes.</p>