Well of course you can do it quickly with vim. Regardless, my suspicion is that OP deleted the lines manually, hence the need to mention it a couple of times. Otherwise, why would they even mention something you can do with grep in a literal second.

you mentioned it twice so I fear the worst, please tell me you didn’t remove 14000 lines manually using a text editor.

a simple explanation but not 100% correct is that even if your code is made to run in parallel using threads, it will never use more than 1 core in your computer.

getting rid of the GIL will let it use all the cores in the processor.

the multiprocessing module “solved” this problem by forking processes instead of threads, but it’s not ideal for a lot of workloads.