title: pandas dataframe view vs copy, how do I tell?
body: <p>What's the difference between:</p>
  
  <p>pandas <code>df.loc[:,('col_a','col_b')]</code></p>
  
  <p>and </p>
  
  <p><code>df.loc[:,['col_a','col_b']]</code></p>
  
  <p>The link below doesn't mention the latter, though it works. Do both pull a view? Does the first pull a view and the second pull a copy? Love learning Pandas.</p>
  
  <p><a href="http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy">http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy</a></p>
  
  <p>Thanks</p>