Reference library

Python Code Samples

Medium snippets you can copy, study, and run in the browser editor.

4 matches
Concurrency & performance medium

How to Use a Bounded Buffer with threading.Condition in Python

Implement a thread-safe bounded buffer using threading.Condition and show a producer–consumer example with exact output.

threading condition producer-consumer
Python 
import threading
import time
import random

class BoundedBuffer:
    def __init__(self, capacity):
        self.capacity = capacity
        self.buffer = []
        self.condition = threading.Condition()

    def put(self, item):
        with self.condition:
            while len(self.buffer) >= self.capacity:
       …
14 0 Open
Concurrency & performance medium

How to Use asyncio Lock to Protect a Shared Counter in Python

This code demonstrates how to use an asyncio.Lock to safely increment a shared counter from multiple concurrent coroutines.

asyncio lock concurrency
Python 
import asyncio

async def increment(counter, lock, increments):
    for _ in range(increments):
        async with lock:
            counter[0] += 1

async def main():
    counter = [0]
    lock = asyncio.Lock()
    tasks = [
        increment(counter, lock, 1000)
        for _ in range(5)
    ]
    await asyncio.gath…
16 0 Open
Concurrency & performance medium

How to Use threading.RLock in Python

Demonstrates threading.RLock, a reentrant lock that allows the same thread to acquire it multiple times without deadlocking — essential for recursive functions sharing state across threads.

threading rlock concurrency
Python 
import threading
import time

lock = threading.RLock()
shared_counter = 0

def recursive_increment(value, depth):
    global shared_counter
    with lock:
        shared_counter += 1
        print(f"Depth {depth}: counter = {shared_counter}")
        if depth > 1:
            recursive_increment(value, depth - 1)

def…
14 0 Open
Concurrency & performance medium

asyncio Condition wait notify pattern in Python

Coordinate coroutines with asyncio.Condition: workers wait for notifications and the main task notifies one or all of them.

asyncio concurrency synchronization
Python 
import asyncio


async def worker(condition, name):
    async with condition:
        print(f"{name} waiting...")
        await condition.wait()
        print(f"{name} notified!")


async def main():
    condition = asyncio.Condition()
    tasks = [asyncio.create_task(worker(condition, f"worker-{i}")) for i in range(3…
14 0 Open

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