Python Code
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How to Check Website Status Codes in Python
This script checks the HTTP status codes of multiple URLs concurrently using a thread pool and prints the results.
import requests
from concurrent.futures import ThreadPoolExecutor
URLS = [
"https://www.google.com",
"https://www.python.org",
"https://www.nonexistent-site-12345.com",
"https://www.github.com",
]
def check_status(url):
try:
response = requests.get(url, timeout=5)
return url, resp…Stress CPU Threads with a Mock Compute in Python
Simulates CPU-intensive work across multiple threads to test how Python schedules parallel compute.
import threading
import time
def stress_cpu(iterations: int):
result = 0
for i in range(iterations):
result += i * i % 1000
return result
def run_mock_stress(thread_count: int, iterations: int):
threads = []
for tid in range(thread_count):
t = threading.Thread(target=lambda: str…How to Use threading.Lock to Synchronize a Counter in Python
Safely increment a shared counter across multiple threads using threading.Lock as a mutex to prevent race conditions.
import threading
counter = 0
lock = threading.Lock()
def increment():
global counter
for _ in range(100000):
with lock:
counter += 1
threads = [threading.Thread(target=increment) for _ in range(5)]
for t in threads:
t.start()
for t in threads:
t.join()
print(f"Final counter valu…How to Wait for the First Future to Complete in Python
Use concurrent.futures.wait with FIRST_COMPLETED to pause until any task finishes and inspect the remaining pending futures.
import concurrent.futures
import time
def task(name, delay):
time.sleep(delay)
return f"{name} done"
if __name__ == "__main__":
with concurrent.futures.ThreadPoolExecutor(max_workers=3) as executor:
futures = [
executor.submit(task, "task1", 2),
executor.submit(task, "ta…How to start, join, and make daemon threads in Python
Starts one daemon and one non-daemon thread, joins the non-daemon thread, and shows how daemon threads exit when the main program ends.
import threading
import time
import logging
logging.basicConfig(level=logging.INFO, format="%(threadName)s: %(message)s")
def worker(name, delay):
for i in range(3):
time.sleep(delay)
logging.info(f"{name} step {i}")
if __name__ == "__main__":
daemon_thread = threading.Thread(
target…Synchronize Threads with a Barrier in Python
Demonstrates using threading.Barrier to synchronize multiple threads at phase boundaries, ensuring all workers wait for each other before proceeding.
import threading
import time
from random import randint
def worker(barrier, worker_id):
for phase in range(3):
time.sleep(randint(1, 3))
print(f"Worker {worker_id} finished phase {phase} at {time.time():.2f}")
barrier.wait()
print(f"Worker {worker_id}: all phases complete")
if __name_…Thread-Safe Producer Consumer Queue in Python
A producer-consumer pattern using thread-safe queue.Queue with two threads, demonstrating safe communication and synchronized task completion.
import queue
import threading
import time
import random
def producer(q, item_count):
for i in range(item_count):
item = random.randint(1, 100)
q.put(item)
print(f"Producer added: {item}")
time.sleep(0.1)
def consumer(q):
while True:
try:
item = q.get(time…How to implement a token bucket rate limiter in Python
A thread-safe in-memory token bucket rate limiter that tracks per-key tokens with refill logic, including a usage example after a timed refill.
import time
import threading
class TokenBucketRateLimiter:
def __init__(self, capacity, refill_rate):
self.capacity = capacity
self.refill_rate = refill_rate
self.tokens = capacity
self.last_refill_time = time.time()
self.lock = threading.Lock()
def allow_request(self,…How to Mock a SIGTERM Handler in Python
Create a graceful shutdown handler for SIGTERM and SIGINT signals, then test it by simulating a signal delivery without terminating the process.
import signal
import time
class Service:
def __init__(self):
self.running = True
def shutdown(self, signum, frame):
print(f"Received signal {signum}, shutting down gracefully...")
self.running = False
def run(self):
signal.signal(signal.SIGTERM, self.shutdown)
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Samples vs tutorials and challenges
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