python爬虫多次请求超时的几种重试方法

第一种方法

headers = Dict()
url = ‘https://www.baidu.com‘
try:
    proxies = None
    response = requests.get(url, headers=headers, verify=False, proxies=None, timeout=3)
except:
    # logdebug(‘requests failed one time‘)
    try:
        proxies = None
        response = requests.get(url, headers=headers, verify=False, proxies=None, timeout=3)
    except:
        # logdebug(‘requests failed two time‘)
        print(‘requests failed two time‘)

总结 ：代码比较冗余，重试try的次数越多，代码行数越多，但是打印日志比较方便

第二种方法

def requestDemo(url，):
	headers = Dict()
	trytimes = 3  #  重试的次数
	for i in range(trytimes):
		try:
		    proxies = None
		    response = requests.get(url, headers=headers, verify=False, proxies=None, timeout=3)
		    #	注意此处也可能是302等状态码
		    if response.status_code == 200:
		    	break
		except:
	    	# logdebug(f‘requests failed {i}time‘)
        	print(f‘requests failed {i} time‘)

总结 ：遍历代码明显比第一个简化了很多，打印日志也方便

第三种方法

def requestDemo(url， times=1):
	headers = Dict()
	try:
	    proxies = None
	    response = requests.get(url, headers=headers, verify=False, proxies=None, timeout=3)
	    html = response.text()
	    #	todo  此处处理代码正常逻辑
	    pass
	    return html
	except:
    	# logdebug(f‘requests failed {i}time‘)
    	trytimes = 3  #  重试的次数
    	if times < trytimes:
    		times += 1
       		return requestDemo(url， times)
       	return ‘out of maxtimes‘

总结 ：迭代 显得比较高大上，中间处理代码时有其它错误照样可以进行重试； 缺点 不太好理解，容易出错，另外try包含的内容过多时，对代码运行速度不利。

第四种方法

@retry(3)	#	重试的次数 3
def requestDemo(url):
	headers = Dict()
    proxies = None
    response = requests.get(url, headers=headers, verify=False, proxies=None, timeout=3)
    html = response.text()
    #	todo  此处处理代码正常逻辑
    pass
    return html
   
def retry(times):
    def wrapper(func):
        def inner_wrapper(*args, **kwargs):
            i = 0
            while i < times:
                try:
                    print(i)
                    return func(*args, **kwargs)
                except:
                	#	此处打印日志  func.__name__ 为say函数
                    print("logdebug: {}()".format(func.__name__))
                    i += 1
        return inner_wrapper
    return wrapper

总结 ：装饰器优点 多种函数复用，使用十分方便

第五种方法

#!/usr/bin/python
# -*-coding=‘utf-8‘ -*-
import requests
import time
import warnings
warnings.filterwarnings("ignore")

def get_xiaomi():
    try:
        # for n in range(5):  # 重试5次
        # print("第"+str(n)+"次")
        for _ in range(5): # 重试5次
            url = "https://www.mi.com/22"
            headers = {
                "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3",
                "Accept-Encoding": "gzip, deflate, br",
                "Accept-Language": "zh-CN,zh;q=0.9,en;q=0.8",
                "Connection": "keep-alive",
                # "Cookie": "xmuuid=XMGUEST-D80D9CE0-910B-11EA-8EE0-3131E8FF9940; Hm_lvt_c3e3e8b3ea48955284516b186acf0f4e=1588929065; XM_agreement=0; pageid=81190ccc4d52f577; lastsource=www.baidu.com; mstuid=1588929065187_5718; log_code=81190ccc4d52f577-e0f893c4337cbe4d|https%3A%2F%2Fwww.mi.com%2F; Hm_lpvt_c3e3e8b3ea48955284516b186acf0f4e=1588929099; mstz=||1156285732.7|||; xm_vistor=1588929065187_5718_1588929065187-1588929100964",
                "Host": "www.mi.com",
                "Upgrade-Insecure-Requests": "1",
                "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.90 Safari/537.36"
            }
            response = requests.get(url,headers=headers,timeout=10,verify=False)
            res= response.text
            # print(res)
            print(response.status_code)
            if response.status_code==200:
                break
        return res
    except:
        result = "异常"
        return result

if __name__ == ‘__main__‘:
    print(get_xiaomi())

第六种方法