import asyncio
from datetime import datetime
import random


async def fetch(url: str, sem: asyncio.Semaphore) -> None:
    async with sem:
        print(f"Fetching of {url} started at {datetime.today()}")
        await asyncio.sleep(round(random.random() + 0.5, 2))
        print(f"Fetching of {url} ended at {datetime.today()}")

async def main():
    semaphor = asyncio.Semaphore(3)
    tasks: list[str] = [fetch(url, semaphor) for url in [f"https://jsonplaceholder.typicode.com/posts/{n}" for n in range(1, 11)]]
    return await asyncio.gather(*tasks)

if __name__ == "__main__":
    asyncio.run(main())