code: def _swapcolumns(self):
      """
      Swaps first and second columns.
      Useful for inverting axis when plotting.
  
      Example:
              df.swapcolumns()
  
      Returns : DataFrame
  
      """
      return self.reindex_axis(
          [self.columns[1], self.columns[0]], axis=1
      )
  
imports: import pandas
  import re
label_desc: Use image node_id 2 for calling a global function with example usage: _swapcolumns() and returns: self