title: Split pandas column into two
body: <p>There are other similar questions, but the difference here is that my dataframe already has a lot of columns, only one of which needs to be split.</p>
  
  <p>I have a large dataframe(hundreds of columns, millions of rows). I would like to split one of these columns when a character ("|") is found in the string.</p>
  
  <p>All values have only one "|".</p>
  
  <p>For a fixed length I would do this:
      df['StateInitial'] = df['state'].str[:2]</p>
  
  <p>I wish I could replace the 2 by string.index("|"), but how do I call the string?</p>