bing 翻译之 asyncio+queue解决失败重抓问题（2）

该爬虫是将本地一批 query（待翻译的文本），通过 bing 翻译的接口进行翻译，采用的是 asyncio 协程进行并发抓取。

问题：该爬虫因代理问题导致抓取任务失败，之前的做法是将失败的 query 写入另一个文件中，手续手动重新抓取，虽然也能解决但是不够智能也过于繁琐。

需求：实现失败自动重抓，直至将所有 query 全部翻译完毕（另外需要实现批量并发抓取）

# coding=utf-8

import asyncio
import json
import sys
import traceback
import aiohttp
from queue import Queue
import redis


class BingSpider:
    def __init__(self, _file_path, _file_name, _ori_lang='auto-detect', _lang='zh-Hans'):
        self.url = 'https://cn.bing.com/ttranslatev3?isVertical=1&&IG=22AB846A476149628EFA6E9FA7863C7B&IID=translator.5025.1'
        self.timeout = 20
        self.f_que = Queue()
        self.file_name = _file_name
        self.file_path = _file_path
        self.ori_lt = _ori_lang
        self.lt = _lang
        self.pool = redis.ConnectionPool(host='', port=6380, password='xxx')
        self.client = redis.Redis(connection_pool=self.pool)
        self.f_ok = None
        self.init_file_obj()

    def init_file_obj(self):
        self.f_ok = open(self.file_name + '_ok', 'w', encoding='utf-8')

    async def get_exception(self):
        """获取错误信息"""
        msg = traceback.format_exc()
        return ",".join(msg.split('\n'))

    async def gen_headers(self):
        headers = {
            'User-Agent': 'xxx'
        }
        return headers

    def read_file(self):
        with open(self.file_path, encoding='utf-8') as f:
            for line in f:
                if not line:
                    continue

                yield line.strip()

    async def fetch(self):
        line = self.f_que.get()  # 从队列中获取待翻译文本
        payload = {
            'fromLang': self.ori_lt,
            'to': self.lt,
            'text': line
        }
        headers = await self.gen_headers()
        proxy = await self.get_available_proxy()  # 获取可靠代理
        status, data = 0, line
        try:
            async with aiohttp.ClientSession(trust_env=True) as session:
                async with session.post(url=self.url, data=payload, timeout=self.timeout, headers=headers,
                                        proxy=proxy) as res:
                    status = res.status
                    content = await res.json()
                    if status == 200 and isinstance(content, list):
                        data = {
                            'origin_lt': self.ori_lt,
                            'lt': self.lt,
                            'origin_lang': line,
                            'translate_str': content[0]['translation'][0]
                        }
        except Exception as e:
            print(e)
            error_msg = await self.get_exception()
            # log.error(f"fetch===>{error_msg}")

        return status, data

    async def check_proxy_post(self, proxy):
        """检查代理"""
        url = 'http://httpbin.org/post'
        status, data = 0, ""
        try:
            payload = {'a': '1', 'b': 2}
            headers = self.gen_headers()
            async with aiohttp.ClientSession(trust_env=True) as session:
                async with session.post(url=url, data=payload, timeout=self.timeout, headers=headers,
                                        proxy=proxy) as res:
                    status = res.status
                    data = await res.text()
        except Exception as e:
            print(e)

        return status, data

    async def get_available_proxy(self):
        while True:
            # 从 redis 获取代理 IP
            ip = self.client.lpop('xxxx')
            if not ip:
                continue

            ip = ip.decode('utf-8')
            proxy = f'http://{ip}'

            # 检查代理是否可用
            status, data = await self.check_proxy_post(proxy)
            if status == 200 and data:
                break

        return proxy

    async def save(self, data):
        """保存"""
        self.f_ok.write(json.dumps(data, ensure_ascii=False))
        self.f_ok.write('\n')

    async def schedule(self):
        """调度"""
        while not self.f_que.empty():
            code, data = await self.fetch()
            if code == 200 and isinstance(data, dict):
                await self.save(data)
            else:
                # 失败的再添加到 f_que 队列中
                self.f_que.put(data)

    def main(self):
        loop = asyncio.get_event_loop()
        work_list = []
        work_num = 300

        # 读取文件，写入队列
        for line in self.read_file():
            self.f_que.put(line)

        # 开启 300 个协程
        for _ in range(work_num):
            work_list.append(
                asyncio.ensure_future(self.schedule(), loop=loop)
            )

        loop.run_until_complete(asyncio.gather(*work_list))

        self.f_ok.close()
        loop.close()


if __name__ == '__main__':
    if len(sys.argv) != 5:
        sys.exit()

    arg_list = sys.argv
    file_name = arg_list[1].strip()  # 生成的文件名
    ori_lang = arg_list[2].strip()  # 原始语种
    lang = arg_list[3].strip()  # 要翻译的语种
    file_path = arg_list[4].strip()  # 本地待翻译文本路径

    bs = BingSpider(file_path, file_name, ori_lang, lang)
    bs.main()