import ROOT,aa

def pythonize_table() :

    # Table can hold any type...
    # instantiate a getter for each of the types we care about.

    types =  { 'i' :  ROOT.int, 
               'd' :  ROOT.double,
               'Ss':  ROOT.string }

    #getattr trick because 'as' is a python keyword :-/
    getters = { s : getattr( ROOT.Value, "as" )[t] for s,t in types.items() } 

    def get_value( cell ) :

        try :
            return getters[ cell.content.type() ]( cell.content )
        except KeyError:
            print ("cannot get value from table cell of type ", t )
            raise TypeError
 
    ROOT.Table.get_at = lambda table,col,row: get_value( table.at( col, row ))

    # assuming the first row holds the column names, return a dict with colname:[value-list]
    ROOT.Table.as_dict = lambda table : \
         { table.get_at(c,0) : 
           [ table.get_at( c,r ) for r in range( 1, table.nrows() ) ] 
           for c in range( 0, table.ncols() )
         }

    def as_dataframe( table ) :
        import pandas
        return pandas.DataFrame(data= table.as_dict() )

    ROOT.Table.as_dataframe = as_dataframe


    # add multiple values at once
    ROOT.Table.oldadd = ROOT.Table.add
    def table_add ( table, *args ) :
        for x in args : table.oldadd( x )
        return table
    ROOT.Table.add = table_add

    



pythonize_table()