#NEWLINE# def apply( self , df ) : #NEWLINE# #INDENT# "\n        Calculate derived feature's values based on the values in the input data frame.\n        Note that the input data frame will not be affected by the transformation.\n        :param df: input data frame\n        :return: array with results\n        " #NEWLINE# assert ( self . function is not None ) , 'Function was not provided' #NEWLINE# assert isinstance ( df , pd . DataFrame ) , 'Input should be a data frame' #NEWLINE# return self . function ( df . copy ( deep = False ) )