混乱的错误:异常.IOError:无法识别图像文件

Question

在不知道图像文件名或跟踪它的响应url的情况下，我多次收到以下错误：

2012-08-20 08:14:34+0000 [spider] Unhandled Error
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 545, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 362, in callback
    self._startRunCallbacks(result)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 458, in _startRunCallbacks
    self._runCallbacks()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 545, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
--- <exception caught here> ---
  File "/usr/lib/pymodules/python2.7/scrapy/contrib/pipeline/images.py", line 204, in media_downloaded
    checksum = self.image_downloaded(response, request, info)
  File "/usr/lib/pymodules/python2.7/scrapy/contrib/pipeline/images.py", line 252, in image_downloaded
    for key, image, buf in self.get_images(response, request, info):
  File "/usr/lib/pymodules/python2.7/scrapy/contrib/pipeline/images.py", line 261, in get_images
    orig_image = Image.open(StringIO(response.body))
  File "/usr/lib/python2.7/dist-packages/PIL/Image.py", line 1980, in open
    raise IOError("cannot identify image file")
exceptions.IOError: cannot identify image file

那么，我该如何解决这个问题呢？因为它在我已经在settings.py 中定义的特定数量的错误后停止了我的spider

Answer 1

有问题的行在scrapy.contrib.pipelines.images.ImagesPipeline:中使用PIL到Image.open()

def get_images(self, response, request, info):
    key = self.image_key(request.url)
    orig_image = Image.open(StringIO(response.body))

media_downloaded（）中的try块捕捉到了这一点，但自身会发出错误：

except Exception:
    log.err(spider=info.spider)

你可以用破解这个文件

try:
    key = self.image_key(request.url)
    checksum = self.image_downloaded(response, request, info)
except ImageException, ex:
    log.msg(str(ex), level=log.WARNING, spider=info.spider)
    raise
except IOError, ex:
    log.msg(str(ex), level=log.WARNING, spider=info.spider)
    raise ImageException
except Exception:
    log.err(spider=info.spider)
    raise ImageException

但更好的选择是创建自己的管道，并覆盖管道中的image_downloaded（）方法。py文件：

from scrapy import log
from scrapy.contrib.pipeline.images import ImagesPipeline
class BkamImagesPipeline(ImagesPipeline):
    def image_downloaded(self, response, request, info):
        try:
            super(BkamImagesPipeline, self).image_downloaded(response, request, info)
        except IOError, ex:
            log.msg(str(ex), level=log.WARNING, spider=info.spider)

请确保在您的设置文件中声明此管道：

ITEM_PIPELINES = [
    'bkam.pipelines.BkamImagesPipeline',
]