decoder.py

import csv

with open("decoderaaa.csv", mode='r') as inp:
	reader = csv.reader(inp)
	ring = {rows[0]:rows[1] for rows in reader}

file_name = input("Enter File Name: ")

input = open(file_name, 'r')
output = open("DECODED-" + file_name, 'w')


for line in input.readlines():
	decode_buffer = ""

	for ch in line:
		decoded = ring.get(ch)

		match decoded:
			case None: decode_buffer += ch
			case other: decode_buffer += decoded
	
	output.write(decode_buffer)