How can I implement semaphores in Python?

How can I implement semaphores in Python?

You can use the threading module in Python, which provides a Semaphore class. Would you like a code example?

Yes, please provide a code example.

Here's a simple example:

import threading
import time

# Create a semaphore with a limit of 2
semaphore = threading.Semaphore(2)

def worker(num):
    print(f'Worker {num} is trying to acquire the semaphore.')
    with semaphore:
        print(f'Worker {num} has acquired the semaphore.')
        time.sleep(2)  # Simulate work
    print(f'Worker {num} has released the semaphore.')

# Create multiple threads
threads = [threading.Thread(target=worker, args=(i,)) for i in range(5)]

# Start the threads
for thread in threads:
    thread.start()

# Wait for all threads to complete
for thread in threads:
    thread.join()

What does the with statement do in this context?

The with statement ensures that the semaphore is released automatically when the block of code is exited, even if an error occurs.