How do I use semaphores in Python?

How do I use semaphores in Python?

You can use the threading module in Python to create semaphores. 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 waiting to enter.')
    with semaphore:
        print(f'Worker {num} has entered.')
        time.sleep(2)
        print(f'Worker {num} is leaving.')

# 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 when the block is exited, even if an error occurs.