一个分布式爬虫框架。比scrapy简单很多,不需要各种item pipeline middwares spider settings run文件之间来回切换写代码,这只需要一个文件,开发时候可以节约很多时间,形式非常松,需要重写一个方发,自己想怎么解析入库都可以,不需要定义item和写pipeline存储。自带的RequestClient支持cookie简单操作,支持一键切换ip代理的使用方式,不需要写这方面的中间件。
# coding=utf-8 from collections import OrderedDict import abc import json import time import queue # noinspection PyUnresolvedReferences from concurrent.futures import ThreadPoolExecutor, ProcessPoolExecutor from threading import Lock # noinspection PyUnresolvedReferences from app.utils_ydf import LoggerMixin, MongoMixin, RedisMixin, RequestClient, decorators, RedisBulkWriteHelper, RedisOperation, MongoBulkWriteHelper, MysqlBulkWriteHelper class BoundedThreadPoolExecutor(ThreadPoolExecutor): def __init__(self, max_workers=None, thread_name_prefix=''): super().__init__(max_workers, thread_name_prefix) self._work_queue = queue.Queue(max_workers * 2) class StatusError(Exception): pass lock = Lock() class BaseCustomSpider(LoggerMixin, MongoMixin, RedisMixin, metaclass=abc.ABCMeta): """ 一个精简的自定义的基于reids任务调度的分布式基础爬虫框架(所谓分布式就是可以水平扩展,一台机器开启多进程不需要修改代码或者多次重复启动python程序,以及多个机器都可以启动此程序,任何节点都可以是生产者或消费者)。子类只需要几行重写_request_and_extract方法,就可以快速开发并发 分布式的爬虫项目,比scrapy简单很多。 用法BookingListPageSpider继承BaseCustomSpider,重写_request_and_extract完成解析和入库。以下为启动方式。 BookingListPageSpider('booking:listpage_urls', threads_num=500).set_request_timeout(100).set_request_proxy('kuai').start_craw() # start_craw是非阻塞的命令,可以直接在当前主线程再运行一个详情页的spider """ def __init__(self, seed_key: str, request_method='get', threads_num=100, proxy_name='kuai'): """ :param seed_key: redis的seed键 :param request_method: 请求方式get或者post :param threads_num:request并发数量 :param proxy_name:可为None, 'kuai', 'abuyun', 'crawlera',为None不使用代理 """ self.__check_proxy_name(proxy_name) self._seed_key = seed_key self._request_metohd = request_method self._proxy_name = proxy_name self.theadpool = BoundedThreadPoolExecutor(threads_num) self._initialization_count() self._request_headers = None self._request_timeout = 60 self._max_request_retry_times = 50 @staticmethod def __check_proxy_name(proxy_name): if proxy_name not in (None, 'kuai', 'abuyun', 'crawlera'): raise ValueError('设置的代理ip名称错误') def _initialization_count(self): self._t1 = time.time() self._request_count = 0 self._request_success_count = 0 def set_max_request_retry_times(self, max_request_retry_times): self._max_request_retry_times = max_request_retry_times return self def set_request_headers(self, headers: dict): """ self.request_headers = {'user-agent':'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36'} """ self._request_headers = headers return self # 使其可以链式操作 def set_request_timeout(self, timeout: float): self._request_timeout = timeout return self def set_request_proxy(self, proxy_name): self.__check_proxy_name(proxy_name) self._proxy_name = proxy_name return self def __calculate_count_per_minute(self, flag): with lock: if time.time() - self._t1 > 60: # _request_count, _request_success_count = self._request_count, self._request_success_count self.logger.info(f'一分钟内请求了 {self._request_count}次 成功了 {self._request_success_count}次, {self._seed_key} 键还有 {self.redis_db7.scard(self._seed_key)} 个种子') self._initialization_count() if flag == 0: self._request_count += 1 if flag == 1: self._request_success_count += 1 def start_craw(self): [self._schedu_a_task() for _ in range(20)] # 如果是读取外网远程reids,获取任务会有一些网络延迟,开10个线程。 @decorators.tomorrow_threads(300) @decorators.keep_circulating(time_sleep=1) def _schedu_a_task(self): while True: seed_bytes = self.redis_db7.spop(self._seed_key) if seed_bytes: seed_dict = json.loads(seed_bytes) self.theadpool.submit(self.__request_and_extract, seed_dict['url'], meta=seed_dict) else: self.logger.debug(f'redis的 {self._seed_key} 键是空的') time.sleep(2) # @decorators.handle_exception(50, ) def _dispacth_request(self, url, current_url_request_times=0, data: dict = None): # self.__calculate_count_per_minute(0) """ :param url: 请求url :param current_url_request_times: :param data: post亲戚逇数据 :return: """ if current_url_request_times < self._max_request_retry_times: if current_url_request_times > 0: pass # self.logger.debug(current_url_request_times) # noinspection PyBroadException try: resp = RequestClient(self._proxy_name, timeout=self._request_timeout).request_with_proxy(method=self._request_metohd, url=url, headers=self._request_headers, data=data) # 使用快代 except Exception as e: self.logger.error(f'request请求网络错误的原因是: {e}') self.__calculate_count_per_minute(0) return self._dispacth_request(url, current_url_request_times + 1) else: if resp.status_code == 200: self.__calculate_count_per_minute(0) self.__calculate_count_per_minute(1) return resp else: self.logger.critical(f'返回状态是 {resp.status_code} --> {url}') self.__calculate_count_per_minute(0) return self._dispacth_request(url, current_url_request_times + 1) else: self.logger.critical(f'请求 {url} 达到最大返回次数后,仍然失败') return f'请求 {url} 达到最大返回次数后,仍然失败' def put_seed_task_to_redis(self, redis_key: str, seed_dict: OrderedDict): """ 添加种子或任务到redis中 :param redis_key: 种子/任务在redis的键 :param seed_dict: 任务,必须是一个有序字典类型,不能用字典,否则会插入相同的任务到redis中。字典中需要至少包含一个名叫url的键,可以添加其余的键用来携带各种初始任务信息。 :return: """ seed_str = json.dumps(seed_dict) # self.redis_db7.sadd(redis_key, seed_str) RedisBulkWriteHelper(self.redis_db7, threshold=50).add_task(RedisOperation('sadd', redis_key, seed_str)) def __request_and_extract(self, url, meta: OrderedDict): # 主要threadpoolexcutor没有毁掉结果时候会不记录错误,错误被隐藏了 # noinspection PyBroadException try: self._request_and_extract(url, meta) except Exception as e: self.logger.exception(f'发生解析错误的url是 {url} \n {e}') @abc.abstractmethod def _request_and_extract(self, url, meta: OrderedDict): """ 子类需要重写此方法,完成解析和数据入库或者加入提取的url二次链接和传递的参数到redis的某个键。爬虫需要多层级页面提取的,重新实例化一个此类运行即可。 :param url: :param meta: :return: """ """ 必须使用_dispacth_request方法来请求url,不要直接使用requests,否则不能够对请求错误成自动重试和每分钟请求数量统计 response = self._dispacth_request(url) print(response.text) """ raise NotImplementedError
写法,只要简单几行就可以,想怎么解析和入库都随你,没有任何约束。
class ExpediaEnglishEdetailSpider(BaseCustomSpider): def _request_and_extract(self, url, meta: dict): response = self._dispacth_request(url) item = dict() item['_id'] = meta['_id'] item['d_country_en'] = re_search_group('<span class="country">(.*?)</span>', response.text) item['d_adress_en'] = re_search_group('<h3>Location</h3>[\s\S]*?<p>(.*?)</p>', response.text) item['d_adress_street_en'] = re_search_group('<span class="street-address">(.*?)</span>', response.text) item.update({'update_time': datetime.datetime.now()}) self.logger.warning(f'更新item --> {item}') MongoBulkWriteHelper(self.mongo_199_client.get_database('hotel').get_collection('expedia_hotel_ydf3'), 100).add_task(UpdateOne({'_id': item['_id']}, {'$set': item},upsert=True))
运行方式:
ExpediaEnglishEdetailSpider('expedia:tasks', threads_num=500).set_request_timeout(100).set_request_proxy('kuai').start_craw()
测试单核单进程每分钟可以请求两万次,每分钟最大的具体请求次数与网速/网站响应速度/内容大小有关。