Python脚本在完成很长一段时间后不会终止

I have a weird problem. I'm loading a huge file (3.5G) and making a dictionary out of it and do some processing. After everything is finished, my script doesn't terminate immediately, it terminates after some time. I think it might be due to memory freeing , what can be other reasons ?? I'd appreciate any opinion. And how can I make my script run faster? I have a weird problem. I'm loading a huge file