装饰器用在爬虫即retrying模块的安装

import requests
from retrying import retry
headers={"User-Agent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36"}

@retry(stop_max_attempt_number=3)
def _parse_url(url,method,data,proxies):
    print("*"*20)
    if method=="POST":
        response = requests.post(url,data=data,headers=headers,proxies=proxies)
    else:
        response = requests.get(url,headers=headers,timeout=3,proxies=proxies)
    assert  response.status_code == 200
    return response.content.decode()


def parse_url(url,method="GET",data=None,proxies={}):
    try:
        html_str = _parse_url(url,method,data,proxies)
    except:
        html_str = None

    return html_str

if __name__ == '__main__':
    url = "www.baidu.com"
    print(parse_url(url))


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None

以及 源码retrying-1.3.3.tar.gz安装，先解压，然后在对应路径下启动cmd, 然后 python setup.py install安装就好了

这里的retrying表示下面的程序连续执行3次，都报错，表示报错。