python爬虫知乎图片_Python爬虫入门教程 25-100 知乎文章图片爬取器之一

1. 知乎文章图片爬取器之一写在前面

今天开始尝试爬取一下知乎，看一下这个网站都有什么好玩的内容可以爬取到，可能断断续续会写几篇文章，今天首先爬取最简单的，单一文章的所有回答，爬取这个没有什么难度。

找到我们要爬取的页面，我随便选了一个

https://www.zhihu.com/question/292393947

1084个回答，数据量可以说非常小了，就爬取它吧。

2. 知乎文章图片爬取器之一选取操作库和爬取地址

爬取使用requests 存储使用 mongodb 就可以了

爬取地址经过分析之后，找到了一个可以返回json的数据接口

提取链接，看一下各参数的意思，方便我们程序模拟

https://www.zhihu.com/api/v4/questions/292393947/answers?include=data%5B%2A%5D.is_normal%2Cadmin_closed_comment%2Creward_info%2Cis_collapsed%2Cannotation_action%2Cannotation_detail%2Ccollapse_reason%2Cis_sticky%2Ccollapsed_by%2Csuggest_edit%2Ccomment_count%2Ccan_comment%2Ccontent%2Ceditable_content%2Cvoteup_count%2Creshipment_settings%2Ccomment_permission%2Ccreated_time%2Cupdated_time%2Creview_info%2Crelevant_info%2Cquestion%2Cexcerpt%2Crelationship.is_authorized%2Cis_author%2Cvoting%2Cis_thanked%2Cis_nothelp%3Bdata%5B%2A%5D.mark_infos%5B%2A%5D.url%3Bdata%5B%2A%5D.author.follower_count%2Cbadge%5B%2A%5D.topics&limit=5&offset=10&sort_by=default

上面的连接进行了URL编码，去找个解码工具解析一下，编程下面的URL就比较好解释了，answers后面跟了一堆的参数，应该是返回的关键字，找到limit每页显示的数据量，offset偏移量，我们下拉滚动条，发现这个在不断的叠加+5，sort_by 就是排序。

https://www.zhihu.com/api/v4/questions/292393947/answers?include=data[*].is_normal,admin_closed_comment,reward_info,is_collapsed,annotation_action,annotation_detail,collapse_reason,is_sticky,collapsed_by,suggest_edit,comment_count,can_comment,content,editable_content,voteup_count,reshipment_settings,comment_permission,created_time,updated_time,review_info,relevant_info,question,excerpt,relationship.is_authorized,is_author,voting,is_thanked,is_nothelp;data[*].mark_infos[*].url;data[*].author.follower_count,badge[*].topics&limit=5&offset=10&sort_by=default

做好上面的工作，接下来就是爬取了，我简化了一下爬取的地址，只保留了一些关键的信息

https://www.zhihu.com/api/v4/questions/292393947/answers?include=comment_count,content,voteup_count,reshipment_settings,is_author,voting,is_thanked,is_nothelp;data[*].mark_infos[*].url;data[*].author.follower_count,badge[*].topics&limit=5&offset=0&sort_by=default

3. 知乎文章图片爬取器之一编写代码

分析完毕之后，发现代码非常简单了

import requests

from fake_useragent import UserAgent

############## 数据存储

import pymongo

import time

DATABASE_IP = '127.0.0.1'

DATABASE_PORT = 27017

DATABASE_NAME = 'sun'

client = pymongo.MongoClient(DATABASE_IP,DATABASE_PORT)

db = client.sun

db.authenticate("dba", "dba")

collection = db.zhihuone # 准备插入数据

##################################

class ZhihuOne(object):

def __init__(self,totle):

self._offset = 0

self._totle = totle

#self._ua = UserAgent()

def run(self):

print("正在抓取 {} 数据".format(self._offset))

headers = {

"upgrade-insecure-requests":"1",

"user-agent": "Mozilla/5.0 (Windows NT 10.0; WOW64)"

}

with requests.Session() as s:

try:

with s.get("https://www.zhihu.com/api/v4/questions/292393947/answers?include=comment_count,content,voteup_count,reshipment_settings,is_author,voting,is_thanked,is_nothelp;data[*].mark_infos[*].url;data[*].author.follower_count,badge[*].topics&limit=5&offset={}&sort_by=default".format(self._offset),headers=headers,timeout=3) as rep:

data = rep.json()

if data:

collection.insert_many(data["data"])

except Exception as e:

print(e.args)

finally:

if self._offset <= self._totle:

self._offset = self._offset + 5 # 每次+5

print("防止被办，休息3s")

time.sleep(3)

self.run()

else: