Comment by mirashii
8 hours ago
The thing that actually makes it harder in Python is threading, because it breaks all ability to reason locally about what might happen and optimize. In Python you have to assume that another thread may do these things at any point mid-execution.
I see no issue here.
Modifying a variable that is read by another thread needs special care in all multithreaded languages I know. If you don't use a synchronization primitive to tell the other thread "hey, this thing here may have changed, read it again from memory"; the other thread is free to use its old value for as long as it whishes.