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我创建了Django File对象的子类来照顾远程文件。 我也想通过创建一个RemoteFileLazy子类化Lazyobject类来创建一个懒惰版本,但它不能像我期望的那样工作。我收到一个错误。RuntimeError:超过最大递归深度:为什么?
import urllib2
from django.core.files.base import File
from django.utils.functional import LazyObject
class RemoteFile(File):
def __init__(self, url):
super(RemoteFile, self).__init__(urllib2.urlopen(urllib2.Request(url)))
def __str__(self):
return 'Remote content'
def __nonzero__(self):
return True
def open(self, mode=None):
self.seek(0)
def close(self):
pass
def chunks(self, chunk_size=None):
# CHUNKS taking care of no known size!
if not chunk_size:
chunk_size = self.DEFAULT_CHUNK_SIZE
if hasattr(self, 'seek'):
self.seek(0)
# Assume the pointer is at zero...
counter = self.size
while True:
data = self.read(chunk_size)
if not data:
break
yield data
class RemoteFileLazy(LazyObject):
def __init__(self, url):
# # as said in the django code: For some reason, we have to inline LazyObject.__init__ here to avoid
# recursion
self._wrapped = None
self.url = url
def _setup(self):
self._wrapped = RemoteFile(self.url)
当我运行这段代码:
rfl = filehelper.RemoteFileLazy(url="http://www.google.fr")
我得到这个错误:
RuntimeError: maximum recursion depth exceeded
任何想法?我没有叫LazyObject。 init因为它在django代码中提到,虽然... 我认为init方法中的“self.url = url”会触发这个错误吗?所以我不能使用具有属性的懒惰对象?
谢谢。
回溯:
c:\Users\Michael\Dropbox\development\tools\Portable Python 2.7.2.1-django1.3.1\App\lib\site-packages\django\utils\functional.pyc in __getattr__(self, name)
274 def __getattr__(self, name):
275 if self._wrapped is None:
--> 276 self._setup()
277 return getattr(self._wrapped, name)
278
C:\Users\Michael\Dropbox\development\projects\django-socialdealing\socialdealing\apps\etl\utils\filehelper.py in _setup(self)
58
59 def _setup(self):
---> 60 self._wrapped = RemoteFile(self.url)
61
62
c:\Users\Michael\Dropbox\development\tools\Portable Python 2.7.2.1-django1.3.1\App\lib\site-packages\django\utils\functional.pyc in __getattr__(self, name)
274 def __getattr__(self, name):
275 if self._wrapped is None:
--> 276 self._setup()
277 return getattr(self._wrapped, name)
278
你可以粘贴一部分追踪,以便我们可以看到什么函数被无限递归? – 2012-02-26 23:21:00
当然,我补充一下。 – Michael 2012-02-26 23:33:07