Python爬虫必备技巧详细总结

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

写入代码

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

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")
    for i in title:
        print(i.text)

for i in range(10):
    baidu(i)
    time.sleep(2)

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原文链接：https://blog.csdn.net/weixin_42403632/article/details/120884472