[ZODB-Dev] "Advanced ZODB for Python Programmers" article: volatile example

[Wichert Akkerman]

On 5/24/10 13:59 , Vincent Pelletier wrote:
> Hi.
>
> I think the example on volatile attributes given in "Advanced ZODB for Python
> Programmers" article[1] shows a bad practice.
>
>> From the article:
>      if hasattr(self, '_v_image'):
>          return self._v_image
>
> This should be rewritten as:
>      try:
>          return self._v_image
>      except AttributeError:

or better:

    marker = []
    value = getattr(self, "_v_image", marker)
    if value is not marker:
        return value

which prevents the exception overhead.

Wichert.