How do I use tabs and spaces? (how to resolve error TabError: inconsistent)

[snippsat]

The problem is that code is written for Python 2.
In Python 3 takes csv module the input in text mode(w), whereas in Python 2 it took it in binary mode(wb).
Then if i rewrite will be like this,tested code with a sample.csv ok.

###################################
# Name script: knab.py            #
# Parameter  : Input file         #
# Author     : Bastiaan Krijgsman #
# Version    : 0.1                #
# Date       : 03-05-2017         #
###################################

from datetime import datetime
import sys
import csv
import os

class Bank:
    ifname = ""
    ofname = ""

    def __init__(self, ifile):
        self.ifname = ifile
        self.ofname = str(os.path.splitext(ifile)[0]) + "_" + str(datetime.now().year) + ".csv"

    def gencsvk(self):  # indentation was wrong on this line
        ifile = open(self.ifname, "r", encoding='utf-8')
        reader = csv.reader(ifile, delimiter=',')

        ofile = open(self.ofname, "w", encoding='utf-8')
        print(ofile)
        writer = csv.writer(ofile, delimiter=';',
                            quotechar='"', quoting=csv.QUOTE_ALL)
        writer.writerow(["Rekening", "Datum", "Omschrijving", "Toelichting", "Opname", "Storting"])

        # "Rekeningnummer","Transactiedatum","Valutacode","CreditDebet","Bedrag","Tegenrekeningnummer","Tegenrekeninghouder","Valutadatum;
        # Betaalwijze;Omschrijving;Type betaling;Machtigingsnummer;Incassant ID;Adres;
        next(reader)  # indentation was wrong on this line
        next(reader)  # indentation was wrong on this line

        for row in reader:
            print(row)

            rekening = row[0]
            datum = row[1]
            # omschrijving = row[10] + " " + row[11] + " " + row[12] + " " + row[13] + \
            #   " " + row[14] + " " + row[15] + " " + row[16] + " " + row[17] + \
            #   " " + row[18]
            omschrijving = row[9]  # indentation was wrong on this line
            opname = 0
            storting = 0
            toelichting = row[5] + " " + row[6] + " " + row[8] + " " + row[13]
            if row[3] == "D":
                opname = row[4]
            if row[3] == "C":
                storting = row[4]

            nrow = rekening, datum, omschrijving, toelichting, opname, storting
            print(row[4] + " " + row[6])
            writer.writerow(nrow)

if len(sys.argv) < 2:
    print("No input file name given!")
    exit()
bank = Bank(sys.argv[1])
bank.gencsvk()