1. Reptile experience
- 1. When we write crawler programs, we can use an object-oriented way to construct code to make the code structure clearer
- 2. When we find that the PC-side webpage of a website is difficult to climb, we can check whether the mobile terminal is easy to climb.
- 3. This crawler mostly uses recursive functions, and recursive functions are a good choice for handling page turning
2. Crawler page display
- List
- Details page
3. Code practice
# coding=utf-8
import requests
from lxml import html
import json
class TiebaSpider:
def __init__(self,tieba_name):
self.tieba_name = tieba_name
self.start_url = "http://tieba.baidu.com/mo/q----,sz@320_240-1-3---2/m?kw="+tieba_name+"&pn=0"
self.part_url = "http://tieba.baidu.com/mo/q----,sz@320_240-1-3---2/"
self.headers= {
"User-Agent":"Mozilla/5.0 (Linux; Android 5.1.1; Nexus 6 Build/LYZ28E) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Mobile Safari/537.36"}
def parse_url(self,url):#发送请求，获取响应
print(url)
response = requests.get(url,headers=self.headers)
return response.content.decode()
def get_content_list(self,html_str):#提取数据
html_str = html.etree.HTML(html_str)
div_list = html_str.xpath("//div[contains(@class,'i')]") #根据div分组
content_list = []
for div in div_list:
item = {
}
item["title"] = div.xpath("./a/text()")[0] if len(div.xpath("./a/text()"))>0 else None
item["href"] = self.part_url+div.xpath("./a/@href")[0] if len(div.xpath("./a/@href"))>0 else None
item["img_list"] = self.get_img_list(item["href"],[])
item["img_list"] = [requests.utils.unquote(i).split("src=")[-1] for i in item["img_list"]]
content_list.append(item)
#提取下一页的url地址
next_url = self.part_url+html.xpath("//a[text()='下一页']/@href")[0] if len(html.xpath("//a[text()='下一页']/@href"))>0 else None
return content_list,next_url
def get_img_list(self,detail_url,total_img_list): #获取帖子中的所有的图片
#3.2请求列表页的url地址，获取详情页的第一页
detail_html_str = self.parse_url(detail_url)
detail_html = html.etree.HTML(detail_html_str)
#3.3提取详情页第一页的图片，提取下一页的地址
img_list = detail_html.xpath("//img[@class='BDE_Image']/@src")
total_img_list.extend(img_list)
#3.4请求详情页下一页的地址，进入循环3.2-3.4
detail_next_url = detail_html.xpath("//a[text()='下一页']/@href")
if len(detail_next_url)>0:
detail_next_url = self.part_url + detail_next_url[0]
return self.get_img_list(detail_next_url,total_img_list)
# else:
# return total_img_list
return total_img_list
def save_content_list(self,content_list): #保存数据
file_path = self.tieba_name+".txt"
with open(file_path,"a",encoding="utf-8") as f:
for content in content_list:
f.write(json.dumps(content,ensure_ascii=False,indent=2))
f.write("\n")
print("保存成功")
def run(self):#实现主要逻辑
next_url = self.start_url
while next_url is not None:
#1.start_url
#2.发送请求，获取响应
html_str = self.parse_url(next_url)
#3.提取数据，提取下一页的url地址
#3.1提取列表页的url地址和标题
#3.2请求列表页的url地址，获取详情页的第一页
#3.3提取详情页第一页的图片，提取下一页的地址
#3.4请求详情页下一页的地址，进入循环3.2-3.4
content_list,next_url = self.get_content_list(html_str)
#4.保存数据
self.save_content_list(content_list)
#5.请求下一页的url地址，进入循环2-5不
if __name__ == '__main__':
# TiebaSpider中可以填写任意想爬取的内容
tieba_spider = TiebaSpider("英雄联盟")
tieba_spider.run()
The above is a case of bloggers crawling all books on Dangdang.com. I hope it can help you
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