How to use a Class to instantiate instance properties for all rows of a specific column?

So I have a very large dataset that has a lot of rows and columns. I'd like to instantiate instance variable properties for all rows of specific columns in the dataframe. I know of how to do this for single variables, but how would I would do this for all rows in a large dataframe? Below is what I've currently used to instantiate the properties of the last values in each column.

class Tranche:
    
    #intializing conduit tranche
    def __init__(self, rating, data):
        self.rating = rating
        self.df = historical_data
        self.cpn = historical_data['Cpn'].iloc[-1]
        self.price = historical_data['Price'].iloc[-1]
        self.moddur = historical_data['ModDur'].iloc[-1]
        self.oas =  historical_data['OAS'].iloc[-1]