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Author: cxhuan

xianhuan/README.md

@@ -10,6 +10,8 @@ Python技术 公众号文章代码库
 
 ## 实例代码
 
+[Python异常还能写得如此优雅！](https://github.com/JustDoPython/python-examples/tree/master/xianhuan/retry)：Python异常还能写得如此优雅！
+
 [神器 Spider！几分钟入门分布式爬虫！](https://github.com/JustDoPython/python-examples/tree/master/xianhuan/disspider)：神器 Spider！几分钟入门分布式爬虫！
 
 [神器！五分钟完成大型爬虫项目！](https://github.com/JustDoPython/python-examples/tree/master/xianhuan/airspider)：神器！五分钟完成大型爬虫项目！

xianhuan/retry/retryingdemo.py

@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+@author: 闲欢
+"""
+import random
+from retrying import retry
+
+
+@retry
+def do_something_unreliable():
+    if random.randint(0, 10) > 1:
+        print("just have a test")
+        raise IOError("raise exception!")
+    else:
+        return "good job!"
+
+
+print(do_something_unreliable())
+
+
+# 最大重试次数
+@retry(stop_max_attempt_number=5)
+def do_something_limited():
+    print("do something several times")
+    raise Exception("raise exception")
+
+# do_something_limited()
+
+
+# 限制最长重试时间（从执行方法开始计算）
+@retry(stop_max_delay=5000)
+def do_something_in_time():
+    print("do something in time")
+    raise Exception("raise exception")
+
+# do_something_in_time()
+
+
+# 设置固定重试时间
+@retry(wait_fixed=2000)
+def wait_fixed_time():
+    print("wait")
+    raise Exception("raise exception")
+
+# wait_fixed_time()
+
+# 设置重试时间的随机范围
+@retry(wait_random_min=1000,wait_random_max=2000)
+def wait_random_time():
+    print("wait")
+    raise Exception("raise exception")
+
+# wait_random_time()
+
+
+# 根据异常重试
+def retry_if_io_error(exception):
+    return isinstance(exception, IOError)
+
+# 设置特定异常类型重试
+@retry(retry_on_exception=retry_if_io_error)
+def retry_special_error():
+    print("retry io error")
+    raise IOError("raise exception")
+
+# retry_special_error()
+
+
+# 通过返回值判断是否重试
+def retry_if_result_none(result):
+    """Return True if we should retry (in this case when result is None), False otherwise"""
+    # return result is None
+    if result =="111":
+        return True
+
+
+@retry(retry_on_result=retry_if_result_none)
+def might_return_none():
+    print("Retry forever ignoring Exceptions with no wait if return value is None")
+    return "111"
+
+might_return_none()
+
+
+
+
+
+
+