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Concurrency & performance

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

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Concurrency & performance medium

How to Speed Up Downloads with ThreadPoolExecutor in Python

Compare sequential and thread-pool download loops to measure real speedup when I/O s bound.

threads concurrency performance
Python 
import time
import threading
from concurrent.futures import ThreadPoolExecutor

def download_file(file_id):
    """Simulate fetching a file by sleeping briefly."""
    time.sleep(0.2)  # pretend network latency
    return f"file_{file_id}"

def sequential_downloads(num_files):
    """Process files one at a time."""
  …
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