Reference library

Concurrency & performance

asyncio, threading, multiprocessing, and profiling-friendly performance patterns.

3 matches
Concurrency & performance easy

How to Memoize Pure Functions with functools.lru_cache in Python

Use functools.lru_cache to memoize a pure Fibonacci function and avoid recomputing repeated values.

lru-cache memoization functools
Python
from functools import lru_cache


@lru_cache(maxsize=128)
def fibonacci(n: int) -> int:
    """Return the nth Fibonacci number (0-indexed) using memoization."""
    if n < 2:
        return n
    return fibonacci(n - 1) + fibonacci(n - 2)


if __name__ == "__main__":
    for i in range(10):
        print(f"fibonacci({…
15 0 Open
Concurrency & performance medium

How to Use threading.local for Per-Thread Data in Python

Use threading.local to keep thread-specific data — each thread gets its own copy of the attribute, so values don't leak between threads.

threading thread-local concurrency
Python
import threading
import time

local_storage = threading.local()

def worker(name):
    local_storage.name = name
    time.sleep(0.1)
    print(f"Thread {threading.current_thread().name}: {local_storage.name}")

if __name__ == "__main__":
    threads = []
    for i in range(3):
        t = threading.Thread(target=worke…
14 0 Open
Concurrency & performance easy

Using a Python Generator Instead of a List to Save Memory

Compare a list approach with a generator to stream values lazily, avoiding memory-heavy storage of large sequences.

generator lazy-evaluation memory
Python
def fibonacci_generator(limit):
    a, b = 0, 1
    count = 0
    while count < limit:
        yield a
        a, b = b, a + b
        count += 1


def sum_first_n(generator, n):
    total = 0
    for i, value in enumerate(generator):
        if i >= n:
            break
        total += value
    return total


if __…
12 0 Open

Browse by section

Each section groups closely related Python snippets.

Concurrency & performance — Python code examples

What you will find here

This page collects concurrency & performance snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.