title: Pandas panel: Copy versus view
body: <p>So basically, if I want to change data in the <em>original df</em>, I always have to use <code>.loc[]</code>. But consider the following</p>
  
  <pre><code>&gt;&gt;&gt; import pandas as pd
  &gt;&gt;&gt; from scipy import random
  &gt;&gt;&gt; from numpy import arange
  
  &gt;&gt;&gt; T, N = 4, 5
  &gt;&gt;&gt; TIndex = arange(0, T)
  &gt;&gt;&gt; FIndex = arange(0, N)
  
  &gt;&gt;&gt; wp = pd.Panel(items=['A', 'w', 'l', 'a', 'x', 'X', 'd', 'profit'],
  ...               major_axis=TIndex, minor_axis=FIndex)
  &gt;&gt;&gt; wp.loc['a', 0, 0] = 0 
  &gt;&gt;&gt; df = wp.loc[0, 'a']
  &gt;&gt;&gt; df.loc[0, 'a'] = 'test'
  &gt;&gt;&gt; df.loc[0, 'a']
  Out[379]: 'test'
  &gt;&gt;&gt; wp.loc['a', 0, 0]
  Out[380]: 0
  </code></pre>
  
  <p>What am I doing wrong? </p>
  
  <p>Also, no <code>SettingWithCopyWarning</code> has been thrown. I typically get these when I do these mistakes on dataframe level. This is highly irritating.</p>