Python loop over 2 files at the same time

Question

I have 2 CSV files of varying lengths. I'm looking for a pythonic way to loop over both of them, pulling data from predefined columns and append that data to my 2 list respectively.

So data from f1 goes to list_A and data from f2 goes to list_B

I realise using zip wont work as the number of rows in each file is different.

list_A = []
list_B = []


with open(file_1,'r') as f1, open(file_2,'r') as f2:
    csvFile_1 = csv.reader(f1, delimiter=',')
    csvFile_2 = csv.reader(f2, delimiter=',')

    for x,y in zip(csvFile_1, csvFile_2):
        list_A.append(x[1])
        list_B.append(y[0])

Any pointers appreciated..

Answer 1

There is no reason to read them with zip, read them independently

with open(file_1, 'r') as f1, open(file_2, 'r') as f2:
    list_A = [x[1] for x in csv.reader(f1, delimiter=',')]
    list_B = [x[0] for x in csv.reader(f2, delimiter=',')]

---

Or use pandas library

import pandas as pd

list_A = pd.read_csv(file_1, sep=',').iloc[:, 1].to_list()
list_B = pd.read_csv(file_2, sep=',').iloc[:, 0].to_list()