Python 怎么写 retry 才够 pythonic？

[lichun]

自己用装饰器写了一个，有什么需要改进的地方吗？

def retry(attempt):
    def decorator(func):
        def wrapper(*args, **kw):
            att = 0
            while att < attempt:
                try:
                    return func(*args, **kw)
                except Exception as e:
                    att += 1
        return wrapper
    return decorator


@rety(attempt=3)
def get_response(url):
    import requests
    r = requests.get('http://xxx')
    return r.content

[dalang]

其实我觉得没什么问题。只是直接捕获 Exception 对后期排障有隐患，而且我更倾向于能明确告知调用者 retry 失败的原因。

def retry(attempt, raise_on_fail=False):
def decorator(func):
def wrapper(*args, **kw):
att = 0
last_except = None
while att < attempt:
try:
return func(*args, **kw)
except Exception as e:
att += 1
last_except = e
else:
if raise_on_fail:
raise Exception('Hit retry threshold, failed for {0}' % str(last_except))
return None
return wrapper
return decorator

[dalang]

额，没对齐果真没法看。不确定回复支部支持 markdown，放个 gist 的链接

https://gist.github.com/dalang/31d4bd34ff5c2f0b031a

[fzinfz]

有很多现成的包的：
https://pypi.python.org/pypi/retrying
https://pypi.python.org/pypi/retry
https://pypi.python.org/pypi/retryz

https://pypi.python.org/pypi?%3Aaction=search&term=retry&submit=search