code: def pivot(self, a, b, Keep=None, NullVals=None, order = None, prefix='_'):
          
          [data,coloring] = spreadsheet.pivot(X=self, a=a, b=b, Keep=Keep, 
                            NullVals=NullVals, order=order, prefix=prefix)
          data = data.view(tabarray)
          data.coloring = coloring
          return data
docs: Pivot with `a` as the row axis and `b` values as the column axis.
  
          Method wraps::
  
                  tabular.spreadsheet.pivot(X, a, b, Keep)