python3判断url链接是否为404的方法

本文实例为大家分享了python3判断url链接是否为404的具体代码，供大家参考，具体内容如下

import pymysql
import threading
import time
import urllib
import requests

# 打开数据库连接
db = pymysql.connect("192.168.0.*", "username", "password", "databasename")
# 使用 cursor() 方法创建一个游标对象 cursor
cursor = db.cursor()
# SQL 查询语句
sql = "SELECT sku,url_6 FROM url_new where flag_6 is null and url_6<>'' "
 # 执行SQL语句
cursor.execute(sql)
 # 获取所有记录列表
results = cursor.fetchall()
num = 0
for row in results:
 sku = row[0]
 url = row[1]
 html = requests.head(url) # 用head方法去请求资源头
 re=html.status_code
 num = num + 1
 print(num,re)
 if re == 200:
   sql_2 = "UPDATE url_new SET flag_6 = 0 WHERE sku = '％s'" ％ sku
   try:
     # 执行SQL语句
     cursor.execute(sql_2)
     #print(cursor.rowcount)
   except Exception as e:
     print(e)
     conn.rollback()
 if re == 404:
   sql_3 = "UPDATE url_new SET flag_6 = 1 WHERE sku = '％s'" ％ sku
   try:
     # 执行SQL语句
     cursor.execute(sql_3)
     print(cursor.rowcount)
   except Exception as e:
     print(e)
     conn.rollback()
 db.commit()
db.close()

来源：https://blog.csdn.net/u013091109/article/details/80737422