downloader

import os
import asyncio
import aiohttp
import aiofiles

semaphore = asyncio.Semaphore(10)

async def get_file(url, dir, file_name=None, file_suf=None, session=None):
    if session is None:
        session = aiohttp.ClientSession()
    if file_name is None:
        file_name = url.split("/")[-1].split(".")[0:-1]
    if file_suf is None:
        file_suf = url.split("/")[-1].split(".")[-1]
    try:
        headers = {
            "User-Agent": "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.1.6) ",
            "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
            "Accept-Language": "en-us",
            "Connection": "keep-alive",
            "Accept-Charset": "GB2312,utf-8;q=0.7,*;q=0.7"}
        file_path = r'{}/{}.{}'.format(dir, file_name, file_suf)
        if os.path.exists(file_path):
            pass
        async with semaphore:
            async with session.get(url, headers=headers) as res:
                res = await res.content.read()
                async with aiofiles.open(file_path, 'ab') as f1:
                    await f1.write(res)
                    await f1.flush()
                    print('下载完成：{}'.format(url))
    except TypeError:
        print('文件链接为空，跳过！')