Python爬虫必备技巧详细总结(腾讯爬虫)

自定义函数

import requests
from bs4 import BeautifulSoup
headers={'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0'}
def baidu(company):
 url = 'https://www.baidu.com/s?rtt=4&tn=news&word=' + company
 print(url)
 html = requests.get(url, headers=headers).text
 s = BeautifulSoup(html, 'html.parser')
 title=s.select('.news-title_1YtI1 a')
 for i in title:
  print(i.text)
# 批量调用函数
companies = ['腾讯', '阿里巴巴', '百度集团']
for i in companies:
 baidu(i)

批量输出多个搜索结果的标题

结果保存为文本文件

import requests
from bs4 import BeautifulSoup
headers={'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0'}
def baidu(company):
 url = 'https://www.baidu.com/s?rtt=4&tn=news&word=' + company
 print(url)
 html = requests.get(url, headers=headers).text
 s = BeautifulSoup(html, 'html.parser')
 title=s.select('.news-title_1YtI1 a')
 fl=open('test.text','a', encoding='utf-8')
 for i in title:
  fl.write(i.text + '\n')
# 批量调用函数
companies = ['腾讯', '阿里巴巴', '百度集团']
for i in companies:
 baidu(i)

写入代码

fl=open('test.text','a', encoding='utf-8')
for i in title:
	fl.write(i.text + '\n')

异常处理

for i in companies:
 try:
  baidu(i)
  print('运行成功')
 except:
  print('运行失败')

写在循环中不会让程序停止运行而会输出运行失败

休眠时间

import time
for i in companies:
 try:
  baidu(i)
  print('运行成功')
 except:
  print('运行失败')
time.sleep(5)

time.sleep(5)

括号里的单位是秒

放在什么位置则在什么位置休眠（暂停）

爬取多页内容

百度搜索腾讯

切换到第二页

去掉多多余的

https://www.baidu.com/s?wd=腾讯&pn=10

分析出

https://www.baidu.com/s?wd=腾讯&pn=0 为第一页
https://www.baidu.com/s?wd=腾讯&pn=10 为第二页
https://www.baidu.com/s?wd=腾讯&pn=20 为第三页
https://www.baidu.com/s?wd=腾讯&pn=30 为第四页
..........

代码

from bs4 import BeautifulSoup
import time
headers={'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0'}
def baidu(c):
 url = 'https://www.baidu.com/s?wd=腾讯&pn=' + str(c)+'0'
 print(url)
 html = requests.get(url, headers=headers).text
 s = BeautifulSoup(html, 'html.parser')
 title=s.select('.t a')
 for i in title:
  print(i.text)
for i in range(10):
 baidu(i)
 time.sleep(2)