What is the output of the following? “`python import threading results = [] lock = threading.Lock() def worker(n): with lock: results.append(n * 2) threads = [threading.Thread(target=worker, args=(i,)) for i in range(3)] for t in threads: t.start() for t in threads: t.join() print(sorted(results)) “`

Question

Python Developer — Hard

What is the output of the following? “`python import threading results = [] lock = threading.Lock() def worker(n): with lock: results.append(n * 2) threads = [threading.Thread(target=worker, args=(i,)) for i in range(3)] for t in threads: t.start() for t in threads: t.join() print(sorted(results)) “`

Accepted Answer

The output of the code will be [0, 2, 4]. The lock ensures that the results list is accessed by only one thread at a time, preventing race conditions. Each thread appends a value to the results list, resulting in [0, 2, 4].