title: Pandas: Refer to column name, case insensitive
body: <p>Using <code>Pandas DataFrame</code>, let's say I have a bunch of columns in a <em>csv</em> file, and I want to be able to access any one of them via case insensitive name.</p>
  
  <pre><code>import pandas as pd
  
  df = pd.read_csv(path_to_csv, delimiter=",")
  
  df2 = df["Size"]
  </code></pre>
  
  <p>The actual column name is <code>"Size"</code>. What can I do so that <code>df2 = df["sIZE"]</code> can also be accepted?</p>