Python tenacity库重试的使用

 1 import time
 2 
 3 import psycopg2
 4 import datetime
 5 from tenacity import *
 6 
 7 g_attempt = 0
 8 
 9 
10 # 直接再异常中进行代码的重试，需要一个global的变量做计数器，方法执行发生异常后重试5次，每次间隔10秒
11 def my_retry_function_v1(conn):
12     global g_attempt
13     conn = None
14     try:
15         conn = psycopg2.connect(**conn)
16         print(‘my_retry_function_v1 execute successfully‘)
17     except Exception as err:
18         g_attempt = g_attempt + 1
19         if g_attempt <= 5:
20             print(str(datetime.datetime.now()) + f‘ :retry---> {str(err)} ‘)
21             print(f‘retrying: {str(g_attempt)}‘)
22             time.sleep(2)
23             return my_retry_function_v1(conn)
24         else:
25             #记录异常，这里仅用print示例
26             print(‘sent a alert notification‘)
27 
28     if conn:
29         return conn
30 
31 
32 #方法执行发生异常后重试5次，每次间隔10秒
33 @retry(stop=stop_after_attempt(5), wait=wait_fixed(10))
34 def my_retry_function_v2(conn):
35     conn = None
36     try:
37         conn = psycopg2.connect(**conn)
38         print(‘my_retry_function_v2 execute successfully‘)
39     except Exception as err:
40         print(datetime.datetime.now().strftime(‘%Y-%m-%d %H:%M:%S.%f‘) + f‘ :retry---> {str(err)} ‘)
41         #达到最大重试之后，记录异常信息
42         if (my_retry_function_v2.retry.statistics[‘attempt_number‘]) == 5:
43             #记录异常，这里仅用print示例
44             print(‘sent a alert notification‘)
45         else:
46             #未超出最大重试次数之前，显式抛出异常,继续重试
47             raise
48     if conn:
49         return conn
50 
51 
52 if __name__== ‘__main__‘:
53     conn = {‘host‘: ‘***.***.***.***‘, ‘database‘: ‘postgres‘, ‘user‘: ‘postgres‘, ‘password‘: ‘******‘,‘port‘:****}
54     my_retry_function_v1(conn)