Python block thread if list is empty
Yes, the solution will probably involve a threading.Condition variable as you note in comments.
Without more information or a code snippet, it's difficult to know what API suits your needs. How are you producing new elements? How are you consuming them? At base, you could do something like this:
cv = threading.Condition()elements = [] # elements is protected by, and signaled by, cvdef produce(...): with cv: ... add elements somehow ... cv.notify_all()def consume(...): with cv: while len(elements) == 0: cv.wait() ... remove elements somehow ...
I would go with this:
import threadingclass MyList (list): def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self._cond = threading.Condition() def append(self, item): with self._cond: super().append(item) self._cond.notify_all() def pop_or_sleep(self): with self._cond: while not len(self): self._cond.wait() return self.pop()