python重试装饰器(Python function retry decorator)
- 2020 年 3 月 12 日
- 筆記
python重试装饰器(Python function retry decorator)
在用requests请求接口或者html的时候，很容易出现超时，限制等各种原因。
在对源代码不进行修改的情况下，可以用装饰器来进行重试
任何函数： 成功，返回-结果，失败，返回–False 都可以用这个装饰器进行重试
1.不需要传参的装饰器写法:
max_retry 为默认重试的次数
import requests def retry(func): def inner(*args, **kwargs): ret = func(*args, **kwargs) max_retry = 3 number = 0 if not ret: while number < max_retry: number += 1 print("尝试第:{}次".format(number)) result = func(*args, **kwargs) if result: break return inner @retry def get_reponse(): headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36' } url = 'https://www.baidu.com' try: r = requests.get(url=url, headers=headers, timeout=0.01) if r.status_code == 200: print(r.headers) return r.headers except requests.exceptions.ReadTimeout: return False except requests.exceptions.ConnectTimeout: return False except Exception: return False get_reponse()
执行结果:
尝试第:1次
尝试第:2次
尝试第:3次
2.需要传参的装饰器写法:
def retry(*args, **kwargs): def warpp(func): def inner(): ret = func() max_retry = kwargs.get('max_retry') # 不传默认重试3次 if not max_retry: max_retry = 3 number = 0 if not ret: while number < max_retry: number += 1 print("尝试第:{}次".format(number)) result = func() if result: break return inner return warpp @retry(max_retry=5) # 不传默认为3次 @retry() 括号需要带 def get_reponse(): headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36' } url = 'https://www.baidu.com' try: r = requests.get(url=url, headers=headers, timeout=0.01) if r.status_code == 200: print(r.headers) return r.headers except requests.exceptions.ReadTimeout: return False except requests.exceptions.ConnectTimeout: return False except Exception: return False get_reponse()
执行结果：
尝试第:1次
尝试第:2次
尝试第:3次
尝试第:4次
尝试第:5次
3. 装饰器在类的用法
import requests class Test: def retry(*args, **kwargs): def warpp(func): def inner(self, *args, **kwargs): ret = func(self, *args, **kwargs) max_retry = kwargs.get('max_retry') # 不传默认重试3次 if not max_retry: max_retry = 3 number = 0 if not ret: while number < max_retry: number += 1 print("尝试第:{}次".format(number)) result = func(self, *args, **kwargs) if result: break return inner return warpp @retry() def get_reponse(self, url): headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36' } try: r = requests.get(url=url, headers=headers, timeout=0.01) if r.status_code == 200: print(r.headers) return r.headers except requests.exceptions.ReadTimeout: return False except requests.exceptions.ConnectTimeout: return False except Exception: return False if __name__ == '__main__': st = Test() url = 'https://www.baidu.com' st.get_reponse(url)
运行结果:
尝试第:1次
尝试第:2次
尝试第:3次
