pyspark self class variable using to read csv file for dataframe

Question

I have to call csv file to read data frame as below format, i can read normal file read but using self variable , i am not aware of it. kindly help us.

from pyspark.sql import SparkSession
class ChargePointsETLJob:
    input_path = 'data/input/electric-chargepoints-2017.csv'
    output_path = 'data/output/chargepoints-2017-analysis'

    def __init__(self):
        self.spark_session = (SparkSession.builder
                                          .master("local[*]")
                                          .appName("ElectricChargePointsETLJob")
                                          .getOrCreate())
    def extract(self):
        pass

    def transform(self, df):
        pass

    def load(self, df):
        pass

    def run(self):
        self.load(self.transform(self.extract()))