title: Random newline character in column list of dataframe resulting in KeyError
body: <p>I have a dataframe of which I'm trying to get only a subset of the columns and then  renaming said columns. </p>
  
  <pre><code>req_cols = ['targetName','suiteName','configName','testName','actualResult_1','actualResult_2','explanation_1']
  
  df = df[req_cols].rename(columns={'targetName':'tgt', 'suiteName':'suite', 'configName':'config', 'testName':'test', 'actualResult_2':'iresult', 'actualResult_1':'gresult', 'explanation_1':'explanation'})
  </code></pre>
  
  <p>I get this error however.</p>
  
  <pre><code>raise KeyError('%s not in index' % objarr[mask])
  KeyError: "['targetName' 'suiteName' 'configName' 'testName' 'actualResult_1'\n 'actualResult_2' 'explanation_1'] not in index"
  </code></pre>
  
  <p>Why does this random newline character appear in this column list?</p>