title: Pandas drop index type columns
body: <p>I want to drop multiple columns from <code>pandas.DataFrame</code> and can't do it. </p>
  
  <pre><code>In [10]: object_columns = X.select_dtypes(['object']).columns
  
  In [10]: type(object_columns)
  
  Out[10]: pandas.core.index.Index
  
  In [11]: X = X.drop(object_columns, inplace=True, axis=1)
  
  ValueError: labels ['VAR_0001' 'VAR_0005' 'VAR_0044' 'VAR_0073'] not contained in axis
  </code></pre>
  
  <p>I change code and it doesn't help:</p>
  
  <pre><code>In [12]: X = X.drop(X[object_columns], inplace=True, axis=1)
  
  KeyError: "['VAR_0001' 'VAR_0005' 'VAR_0044' 'VAR_0073'] not in index"
  </code></pre>
  
  <p>Can anybody explain what I doing wrong?</p>