用python写一个程序实现从一个文本文件里读取n行的url然后使用协程多进程并发访问这些url每批最多m进程且mn并给出返回值

下面是一个使用协程和多进程并发访问url的示例程序：

import asyncio
import aiohttp
from concurrent.futures import ThreadPoolExecutor, ProcessPoolExecutor

async def fetch(session, url):
    async with session.get(url) as response:
        return await response.text()

async def process_urls(urls, max_concurrent):
    semaphore = asyncio.Semaphore(max_concurrent)
    async with aiohttp.ClientSession() as session:
        tasks = []
        for url in urls:
            task = asyncio.ensure_future(process_url(session, url, semaphore))
            tasks.append(task)
        return await asyncio.gather(*tasks)

async def process_url(session, url, semaphore):
    async with semaphore:
        return await fetch(session, url)

def read_urls_from_file(file_name):
    with open(file_name, 'r') as file:
        return file.read().splitlines()

def main():
    file_name = 'urls.txt'
    num_lines = 10  # 读取的行数
    max_concurrent = 5  # 每批最多的进程数，即并发请求数

    urls = read_urls_from_file(file_name)[:num_lines]

    loop = asyncio.get_event_loop()
    executor = ThreadPoolExecutor(max_workers=max_concurrent)
    asyncio.set_event_loop(loop)

    try:
        result = loop.run_until_complete(process_urls(urls, max_concurrent))
        print(result)
    finally:
        loop.close()

if __name__ == '__main__':
    main()

上述程序首先使用read_urls_from_file()函数从文件中读取指定行数的url。然后定义了fetch()函数，使用aiohttp库发起异步的url请求并获取返回的文本内容。

process_url()函数使用semaphore来限制并发请求数，实现每批最多m个进程。

process_urls()函数创建一个ClientSession对象，然后使用asyncio.gather()同时执行多个process_url()函数，返回所有url的文本结果。

在main()函数中，我们指定了读取的行数和每批最多的进程数。然后使用asyncio的事件循环来运行process_urls()函数，最后获取返回的结果并打印