如何修改它以从右到左读取并提取行？ 而不是从左到右阅读

Question

with this script I am able to separate lines into different text files based on the position of ",". Instead of reading and choosing the "," from left to right, how can I modify it so it reads from right to left? In my list.txt example, I would like to extract "1" from the first line, "14" from the second line, and "3" from the third line.

with open("list.txt", 'r') as file:
   for line in file:
      parts = line.strip().split(',')
      with open(f"{parts[2]}.txt", 'a+') as file2:
         file2.write(line)

list.txt

Honda,engine,1,yes
Honda,cooling+system,car,14,no
Honda,heat+&+air+conditioning,heat,car,3,no

Answer 1

with open("list.txt", 'r') as file, :
   for line in file:
      parts = line.strip().split(',')
      parts = parts[::-1]  # reverses the list
      with open(f"{parts[1]}.txt", 'a+') as file2: # number is the second element so index is 1
         file2.write(line)

OR simply use index from right starting with -1 and you need -2 as below:

with open("list.txt", 'r') as file, :
   for line in file:
      parts = line.strip().split(',')
      with open(f"{parts[-2]}.txt", 'a+') as file2:
         file2.write(line)