I'm getting the following error in my code.

if self.time_step_period == self.the_num_of_job [self.curr_time]:
IndexError: list index out of range

I think this is trying to refer to self.curr_time outside the list self.the_num_of_job element. However, when this error occurs, the value of self.curr_time is 0, and self.the_num_of_job should have a value, so it is strange to get an error.
The source here is part of a function, but it works fine when running alone. However, the above error occurred during multi-thread processing.

from multiprocessing import Process
from multiprocessing import Manager

I import and use the above. I'm not very familiar with multi-threaded code and I don't know why, but I'm using the multi-threaded processing that was originally completed, so there's nothing wrong with the way it is written. I'm editing the function by myself, so there is an error, but I don't understand the cause at all ... It might be a bit of a vague question, but I can't see the cause, so the entire code It is a situation that can not be raised, but anyway, there is a list index out of range even though it is within the range of the list, this is a possible cause from the fact that it is an error that occurs during multithread processing Will there be?