接下来在迭代器中优雅地捕获 python 异常

Question

我正在使用 PyGithub 来抓取一些存储库，但在迭代搜索页面时遇到一些错误。

def scrape_interval(self, interval):
    for repo_number, repo in self.search(interval):
        code...

def search(self, interval):
    try:
        iterator = enumerate(self.github.search_repositories(query="Laravel created:" + interval))
    except:
        print.warning("Going to sleep for 1 hour. The search API hit the limit")
        time.sleep(3600)
        iterator = self.search(interval)
    return iterator

正如您所看到的，我在创建迭代器时尝试捕获错误def search。但是错误是在线抛出的for repo_number, repo in self.search(interval):，所以是在迭代器获取下一个项目的某个时刻？

我可以选择哪些选项来捕获这些错误？我最好避免将整个 for 循环包装在 try 子句中，而是在迭代本身期间对其进行管理。

有关错误本身的参考：

File "/Users/olofjondelius/Documents/Code/laravel-ai/src/examples/migration-analysis/../../GithubScraper.py", line 47, in scrape_interval
    for repo_number, repo in self.search(interval):
  File "/anaconda3/envs/laravel-ai/lib/python3.7/site-packages/github/PaginatedList.py", line 58, in _iter_
    newElements = self._grow()
  File "/anaconda3/envs/laravel-ai/lib/python3.7/site-packages/github/PaginatedList.py", line 70, in _grow
    newElements = self._fetchNextPage()
  File "/anaconda3/envs/laravel-ai/lib/python3.7/site-packages/github/PaginatedList.py", line 172, in _fetchNextPage
    headers=self.__headers
  File "/anaconda3/envs/laravel-ai/lib/python3.7/site-packages/github/Requester.py", line 185, in requestJsonAndCheck
    return self.__check(*self.requestJson(verb, url, parameters, headers, input, cnx))
  File "/anaconda3/envs/laravel-ai/lib/python3.7/site-packages/github/Requester.py", line 231, in requestJson
    return self.__requestEncode(cnx, verb, url, parameters, headers, input, encode)
  File "/anaconda3/envs/laravel-ai/lib/python3.7/site-packages/github/Requester.py", line 284, in __requestEncode
    status, responseHeaders, output = self.__requestRaw(cnx, verb, url, requestHeaders, encoded_input)
  File "/anaconda3/envs/laravel-ai/lib/python3.7/site-packages/github/Requester.py", line 309, in __requestRaw
    requestHeaders
  File "/anaconda3/envs/laravel-ai/lib/python3.7/http/client.py", line 1229, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/anaconda3/envs/laravel-ai/lib/python3.7/http/client.py", line 1275, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/anaconda3/envs/laravel-ai/lib/python3.7/http/client.py", line 1224, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/anaconda3/envs/laravel-ai/lib/python3.7/http/client.py", line 1016, in _send_output
    self.send(msg)
  File "/anaconda3/envs/laravel-ai/lib/python3.7/http/client.py", line 956, in send
    self.connect()
  File "/anaconda3/envs/laravel-ai/lib/python3.7/http/client.py", line 1384, in connect
    super().connect()
  File "/anaconda3/envs/laravel-ai/lib/python3.7/http/client.py", line 928, in connect
    (self.host,self.port), self.timeout, self.source_address)
  File "/anaconda3/envs/laravel-ai/lib/python3.7/socket.py", line 707, in create_connection
    for res in getaddrinfo(host, port, 0, SOCK_STREAM):
  File "/anaconda3/envs/laravel-ai/lib/python3.7/socket.py", line 748, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 8] nodename nor servname provided, or not known

Answer 1

听起来好像是在迭代迭代器时而不是创建迭代器时引发异常。您的 currenttry和except块仅捕获您调用时立即引发的异常self.github.search_repositories，而不是您使用结果时出现的任何异常。

为了解决这个问题，你可以让你的search函数成为一个生成器。这将让您在拥有值的同时产生值，但仍然可以捕获异常并根据需要经常重试。

尝试这样的事情：

def search(self, interval):
    while True:
        try:
            it = enumerate(self.github.search_repositories(query="Laravel created:" + interval))
            yield from it
            return   # if we completed the yield from without an exception, we're done!

        except:  # you should probably limit this to catching a specific exception types
            print.warning("Going to sleep for 1 hour. The search API hit the limit")
            time.sleep(3600)

正如我在评论中指出的那样，您可能应该将纯except语句更改为except socket.gaierror或类似的内容，这样您就不会抑制所有异常，而只会抑制您期望的异常，并且延迟将为您解决。真正意外的事情仍然应该允许停止程序（因为它可能反映了代码中其他地方的错误）。