code: def columnwise_summary(sf):
      
      if not isinstance(sf, tc.data_structures.sframe.SFrame):
          raise ValueError("turicreate.visualization.columnwise_summary " + 
              "supports SFrame")
      plt_ref = tc.extensions.plot_columnwise_summary(sf)
      return Plot(plt_ref)
docs: Plots a columnwise summary of the sframe provided as input, 
      and returns the resulting Plot object.
      
      The function supports SFrames.
  
      Parameters
      ----------
      sf : SFrame
        The data to get a columnwise summary for.
      
      Returns
      -------
      out : Plot
        A :class: Plot object that is the columnwise summary plot.
  
      Examples
      --------
      Make a columnwise summary of an SFrame.
  
      >>> x = turicreate.SArray([1,2,3,4,5])
      >>> s = turicreate.SArray(['a','b','c','a','a'])
      >>> sf_test = turicreate.SFrame([x,x,x,x,s,s,s,x,s,x,s,s,s,x,x])
      >>> colsum = turicreate.visualization.columnwise_summary(sf_test)