code: def dmap2lin(df,idxn='index',coln='column',colvalue_name='value'):
      
  #     df.columns.name=coln
      df.index.name=idxn
      return df.reset_index().melt(id_vars=[df.index.name],
                               var_name=coln,value_name=colvalue_name)
docs: dmap: ids in index and columns 
      idxn,coln of dmap -> 1st and 2nd col