手把手教你用Scrapy爬取知乎大V粉丝列表

2021-05-06 14:58:32 浏览数 (1)

导读:通过获取知乎某个大V的关注列表和被关注列表,查看该大V以及其关注用户和被关注用户的详细信息,然后通过层层递归调用,实现获取关注用户和被关注用户的关注列表和被关注列表,最终实现获取大量用户信息。

作者:赵国生 王健

来源:大数据DT(ID:hzdashuju)

新建一个Scrapy项目scrapy startproject zhihuuser,移动到新建目录cdzhihuuser下。新建Spider项目:scrapy genspider zhihu zhihu.com。

01 定义spider.py文件

定义爬取网址、爬取规则等。

代码语言:javascript复制
# -*- coding: utf-8 -*-
import json
from scrapy import Spider, Request
from zhihuuser.items import UserItem
class ZhihuSpider(Spider):
    name = 'zhihu'
    allowed_domains = ['zhihu.com']
    start_urls = ['http://zhihu.com/']
# 自定义爬取网址
    start_user = 'excited-vczh'
    user_url = 'https://www.zhihu.com/api/v4/members/{user}?include={include}'
    user_query = 'allow_message,is_followed,is_following,is_org,is_blocking,employments,answer_count,follower_count,articles_count,gender,badge[?(type=best_answerer)].topics'
    follows_url = 'https://www.zhihu.com/api/v4/members/{user}/followees?include= {include}&offset={offset}&limit={limit}'
    follows_query = 'data[*].answer_count,articles_count,gender,follower_count,is_followed,is_following,badge[?(type=best_answerer)].topics'
    followers_url = 'https://www.zhihu.com/api/v4/members/{user}/followees?include= {include}&offset={offset}&limit={limit}'
    followers_query = 'data[*].answer_count,articles_count,gender,follower_count,is_followed,is_following,badge[?(type=best_answerer)].topics'
# 定义请求爬取用户信息、关注用户和被关注用户的函数
    def start_requests(self):
        yield Request(self.user_url.format(user=self.start_user, include=self.user_query), callback=self.parseUser)
        yield Request(self.follows_url.format(user=self.start_user, include=self.follows_query, offset=0, limit=20), callback=self.parseFollows)
        yield Request(self.followers_url.format(user=self.start_user, include=self.followers_query, offset=0, limit=20), callback=self.parseFollowers)
# 请求爬取用户详细信息
    def parseUser(self, response):
        result = json.loads(response.text)
        item = UserItem()
        for field in item.fields:
            if field in result.keys():
                item[field] = result.get(field)
        yield item
# 定义回调函数,爬取关注用户与被关注用户的详细信息,实现层层迭代
        yield Request(self.follows_url.format(user=result.get('url_token'), include=self.follows_query, offset=0, limit=20), callback=self.parseFollows)
        yield Request(self.followers_url.format(user=result.get('url_token'), include=self.followers_query, offset=0, limit=20), callback=self.parseFollowers)
# 爬取关注者列表
    def parseFollows(self, response):
        results = json.loads(response.text)
        if 'data' in results.keys():
            for result in results.get('data'):
                yield Request(self.user_url.format(user=result.get('url_token'), include=self.user_query), callback=self.parseUser)
        if 'paging' in results.keys() and results.get('paging').get('is_end') == False:
            next_page = results.get('paging').get('next')
            yield Request(next_page, callback=self.parseFollows)
# 爬取被关注者列表
    def parseFollowers(self, response):
        results = json.loads(response.text)
        if 'data' in results.keys():
            for result in results.get('data'):
                yield Request(self.user_url.format(user=result.get('url_token'), include=self.user_query), callback=self.parseUser)
        if 'paging' in results.keys() and results.get('paging').get('is_end') == False:
            next_page = results.get('paging').get('next')
            yield Request(next_page, callback=self.parseFollowers)

02 定义items.py文件

定义爬取数据的信息、使其规整等。

代码语言:javascript复制
# -*- coding: utf-8 -*-
# Define here the models for your scraped items
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/items.html
from scrapy import Field, Item
class UserItem(Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    allow_message = Field()
    answer_count = Field()
    articles_count = Field()
    avatar_url = Field()
    avatar_url_template = Field()
    badge = Field()
    employments = Field()
    follower_count = Field()
    gender = Field()
    headline = Field()
    id = Field()
    name = Field()
    type = Field()
    url = Field()
    url_token = Field()
    user_type = Field()

03 定义pipelines.py文件

存储数据到MongoDB。

代码语言:javascript复制
# -*- coding: utf-8 -*-
# Define your item pipelines here
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html
import pymongo
# 存储到MongoDB
class MongoPipeline(object):
    collection_name = 'users'
    def __init__(self, mongo_uri, mongo_db):
        self.mongo_uri = mongo_uri
        self.mongo_db = mongo_db
    @classmethod
    def from_crawler(cls, crawler):
        return cls(
            mongo_uri=crawler.settings.get('MONGO_URI'),
            mongo_db=crawler.settings.get('MONGO_DATABASE')
        )
    def open_spider(self, spider):
        self.client = pymongo.MongoClient(self.mongo_uri)
        self.db = self.client[self.mongo_db]
    def close_spider(self, spider):
        self.client.close()
    def process_item(self, item, spider):
        self.db[self.collection_name].update({'url_token':item['url_token']}, dict(item), True)
# 执行去重操作
        return item

04 定义settings.py文件

开启MongoDB、定义请求头、不遵循robotstxt规则。

代码语言:javascript复制
# -*- coding: utf-8 -*-
BOT_NAME = 'zhihuuser'
SPIDER_MODULES = ['zhihuuser.spiders']
# Obey robots.txt rules
ROBOTSTXT_OBEY = False  # 是否遵守robotstxt规则,限制爬取内容
# Override the default request headers(加载请求头):
DEFAULT_REQUEST_HEADERS = {
    'Accept': 'text/html,application/xhtml xml,application/xml;q=0.9,*/*;q=0.8',
    'Accept-Language': 'en',
    'User-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/ 537.36 (KHTML, like Gecko) Chrome/64.0.3282.140 Safari/537.36',
    'authorization': 'oauth c3cef7c66a1843f8b3a9e6a1e3160e20'
}
# Configure item pipelines
# See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES = {
    'zhihuuser.pipelines.MongoPipeline': 300,
}
MONGO_URI = 'localhost'
MONGO_DATABASE = 'zhihu'

开启爬取:scrapycrawlzhihu。部分爬取过程中的信息如图8-4所示。

▲图8-4 部分爬取过程中的信息

存储到MongoDB的部分信息如图8-5所示。

▲图8-5 MongoDB的部分信息

关于作者:赵国生,哈尔滨师范大学教授,工学博士,硕士生导师,黑龙江省网络安全技术领域特殊人才。主要从事可信网络、入侵容忍、认知计算、物联网安全等方向的教学与科研工作。

本文摘编自《Python网络爬虫技术与实战》,经出版方授权发布。

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