code: def indexcol(self, col: str):
          
          try:
              self.df[col] = self.df.index.values
          except Exception as e:
              self.err(e)
              return
          self.ok("Column", col, "added from the index")
docs: Add a column from the index
  
          :param col: name of the new column
          :type col: str
  
          :example: ``ds.index_col("New col")``