python - 捕获在 greenlet 中引发的异常

Question

我正在 try catch greenlet 中引发的异常。根据this tutorial ，不幸的是“在 Greenlet 中引发异常，留在 Greenlet 中”。在下面的代码中，我有一个生成爬行 greenlet 的同步方法。那些爬行 greenlets 引发了 HTTPError 异常，我需要在 sync 方法的主体中捕获它。基于异常，在 sync 方法中我将设置 Account 对象的适当状态。知道如何在同步方法中捕获在 greenlets 中引发的异常以实现这一点吗？先感谢您!

# this is standalone helper method
def crawl(item):
    try:
        item.refresh_children(False) # THROWS HTTPError exception
        greenlets = [gevent.spawn_link_exception(crawl, child) for child in item.children]
        gevent.joinall(greenlets)
    except HTTPError, e:
        print e.message
        raise e
    except (JSONDecodeError, InvalidCredentialsException) as e:
        print e.message
        raise e

# this is instance method of the Account class 
def sync(self):
    "Sync search index with data from source"
    try:
        greenlets = [gevent.spawn_link_exception(crawl, item) for item in self.get_navigation()]
        gevent.joinall(greenlets)
        self.date_synced = datetime.datetime.now()
        self.save()
    except HTTPError, e:
        if e.status_code == 401:
            self.status = 'revoked'
        else:
            self.status = 'error'
        self.save()
    except LinkedFailed, e:
        print e.message
        exception_name = e.message.split()[-1]
        if exception_name in ['HTTPError', 'JSONDecodeError']:
            self.status = 'error'
            self.save()
        elif exception_name == 'InvalidCredentialsException':
            self.status = 'revoked'
            self.save()

Answer 1

Greenlets 将保存为 greenlet 或异常生成的函数的结果，如果有的话。您可以使用 get 获取结果或重新引发异常。方法。 由于您似乎正在根据任何错误的 greenlet 更改状态，因此同步方法最终看起来像这样:

def sync(self):
    "Sync search index with data from source"
    greenlets = [gevent.spawn_link_exception(crawl, item) for item in self.get_navigation()]
    gevent.joinall(greenlets)
    try:
        results = [greenlet.get() for greenlet in greenlets]
    except HTTPError, e:
        if e.status_code == 401:
            self.status = 'revoked'
        else:
            self.status = 'error'
        self.save()
    except LinkedFailed, e:
        print e.message
        exception_name = e.message.split()[-1]
        if exception_name in ['HTTPError', 'JSONDecodeError']:
            self.status = 'error'
            self.save()
        elif exception_name == 'InvalidCredentialsException':
            self.status = 'revoked'
            self.save()

    self.date_synced = datetime.datetime.now()
    self.save()