Set class with timed auto remove of elements

Question

I\'m writing a software with Python and I need a class to store a set of elements (order is not relevant and not repeated elements), like the Python class set,

Answer 1

I don't see any reason not to go with multithreading. As it is really easy to implement, with minimum code. Roughly something like this:

import threading
import time

def ttl_set_remove(my_set, item, ttl):
    time.sleep(ttl)
    my_set.remove(item)

class MySet(set):
    def add(self, item, ttl):
        set.add(self, item)
        t = threading.Thread(target=ttl_set_remove, args=(self, item, ttl))
        t.start()

test:

s = MySet()
s.add('a', 20)
s.add('b', 10)
s.add('c', 2)

print(s)
time.sleep(5)
print(s)

>>> 
MySet({'c', 'b', 'a'})
MySet({'b', 'a'})