分享一个基于 asyncio 的爬虫微框架 AntNest，来 fork 啊

[WuMingyu]

楼主之前干过一段时间的爬虫，而且正好 python 的 asyncio 比较新，但逛了一圈没发现觉得好用的框架，就造了这么个轮子，废话少说，看看一个例子

from ant_nest import *
from yarl import URL


class GithubAnt(Ant):
    """Crawl trending repositories from github"""
    item_pipelines = [
        ItemFieldReplacePipeline(
            ('meta_content', 'star', 'fork'),
            excess_chars=('\r', '\n', '\t', '  '))
    ]
    concurrent_limit = 1  # save the website`s and your bandwidth!

    def __init__(self):
        super().__init__()
        self.item_extractor = ItemExtractor(dict)
        self.item_extractor.add_pattern(
            'xpath', 'title', '//h1/strong/a/text()')
        self.item_extractor.add_pattern(
            'xpath', 'author', '//h1/span/a/text()', default='Not found')
        self.item_extractor.add_pattern(
            'xpath', 'meta_content',
            '//div[@class="repository-meta-content col-11 mb-1"]//text()',
            extract_type=ItemExtractor.EXTRACT_WITH_JOIN_ALL)
        self.item_extractor.add_pattern(
            'xpath',
            'star', '//a[@class="social-count js-social-count"]/text()')
        self.item_extractor.add_pattern(
            'xpath', 'fork', '//a[@class="social-count"]/text()')

    async def crawl_repo(self, url):
        """Crawl information from one repo"""
        response = await self.request(url)
        # extract item from response
        item = self.item_extractor.extract(response)
        item['origin_url'] = response.url

        await self.collect(item)  # let item go through pipelines(be cleaned)
        self.logger.info('*' * 70 + 'I got one hot repo!\n' + str(item))

    async def run(self):
        """App entrance, our play ground"""
        response = await self.request('https://github.com/explore')
        for url in response.html_element.xpath(
                '/html/body/div[4]/div[2]/div/div[2]/div[1]/article//h1/a[2]/'
                '@href'):
            # crawl many repos with our coroutines pool
            self.schedule_coroutine(
                self.crawl_repo(response.url.join(URL(url))))
        self.logger.info('Waiting...')

输出：

>>> ant_nest -a ants.example2.GithubAnt
INFO:GithubAnt:Opening
INFO:GithubAnt:Waiting...
INFO:GithubAnt:**********************************************************************I got one hot repo!
{'title': 'NLP-progress', 'author': 'sebastianruder', 'meta_content': 'Repository to track the progress in Natural Language Processing (NLP), including the datasets and the current state-of-the-art for the most common NLP tasks.', 'star': '3,743', 'fork': '327', 'origin_url': URL('https://github.com/sebastianruder/NLP-progress')}
INFO:GithubAnt:**********************************************************************I got one hot repo!
{'title': 'material-dashboard', 'author': 'creativetimofficial', 'meta_content': 'Material Dashboard - Open Source Bootstrap 4 Material Design Adminhttps://demos.creative-tim.com/materi …', 'star': '6,032', 'fork': '187', 'origin_url': URL('https://github.com/creativetimofficial/material-dashboard')}
INFO:GithubAnt:**********************************************************************I got one hot repo!
{'title': 'mkcert', 'author': 'FiloSottile', 'meta_content': "A simple zero-config tool to make locally-trusted development certificates with any names you'd like.", 'star': '2,311', 'fork': '60', 'origin_url': URL('https://github.com/FiloSottile/mkcert')}
INFO:GithubAnt:**********************************************************************I got one hot repo!
{'title': 'pure-bash-bible', 'author': 'dylanaraps', 'meta_content': '📖 A collection of pure bash alternatives to external processes.', 'star': '6,385', 'fork': '210', 'origin_url': URL('https://github.com/dylanaraps/pure-bash-bible')}
INFO:GithubAnt:**********************************************************************I got one hot repo!
{'title': 'flutter', 'author': 'flutter', 'meta_content': 'Flutter makes it easy and fast to build beautiful mobile apps.https://flutter.io', 'star': '30,579', 'fork': '1,337', 'origin_url': URL('https://github.com/flutter/flutter')}
INFO:GithubAnt:**********************************************************************I got one hot repo!
{'title': 'Java-Interview', 'author': 'crossoverJie', 'meta_content': '👨\u200d🎓 Java related : basic, concurrent, algorithm https://crossoverjie.top/categories/J …', 'star': '4,687', 'fork': '409', 'origin_url': URL('https://github.com/crossoverJie/Java-Interview')}
INFO:GithubAnt:Closed
INFO:GithubAnt:Get 7 Request in total
INFO:GithubAnt:Get 7 Response in total
INFO:GithubAnt:Get 6 dict in total
INFO:GithubAnt:Run GithubAnt in 18.157656 seconds

这里一些有趣的概念: Item、Pipeline 和 ItemExtractor

Item 代表存储爬取数据的容器，这个容器有很多表现形式，可以是任何支持 set|get item|attribute 的对象, 比如 dict、标准 Class, AttrsClass 或者 DataClass 甚至 ORM 的 Class 对象

Pipeline 类似 scrapy 的 Pipeline，每个 Request、Response 和 Item 都可以通过一系列的 Pipeline

ItemExtractor 用来声明如何从源数据解析出 Item, 支持 xpath、jpath 和 regex

还有一些比如协程的工作流、HTTP 的封装等等限于篇幅不再赘述，整个框架就 600 行左右的核心代码，思路也都很简单，不清楚的可以直接看代码。 有爬虫需求的可以试试，看看能不能加快写代码的速度，也欢迎大佬提建议，放上地址： https://github.com/strongbugman/ant_nest

[yuanfnadi]

感觉爬虫难点在于 IP 反爬 分布式调度。楼主这方面有轮子推荐吗。

[WuMingyu]

@yuanfnadi 如果说分布式是为了利用多个 ip 的话，不如部署一个分布式代理池，爬虫进程还是单点跑

[yuanfnadi]

@WuMingyu 分布式就是多个爬虫共享进度 任务 不会重复。