python newbie - question about lexical scoping

[Matt Barnicle]

>> On Dec 1, 4:47 pm, Matt Barnicle <ma... at wageslavery.org> wrote:
> aye yaye aye...  thanks for the pointers in the right direction..  i
> fiddled around with the code for a while and now i've reduced it to the
> *real* issue...  i have a class dict variable that apparently holds its
> value across instantiations of new objects..  the problem can be
> illustrated in the following much simpler code:
>
>>>> class foo():
> ...     bar = { 'baz': 'bing' }
> ...
>>>> a = foo()
>>>> a.bar
> {'baz': 'bing'}
>>>> a.bar['baz'] = 'bong'
>>>> a.bar
> {'baz': 'bong'}
>>>> b = foo()
>>>> b.bar
> {'baz': 'bong'}

ok, i see...  python has a concept i'm not accustomed to which i found
described here:

http://zephyrfalcon.org/labs/python_pitfalls.html
4. Class attributes vs instance attributes

so i'm sure what is going on is obvious to experienced python
programmers...  i'm not really sure how to get around this though.  i'll
need to spend some time on reworking our models code i guess...  i
inherited this from someone, and what he was trying to do was to set
default values for objects representing tables (in kind of a simple ORM
layer) and storing the values in a dict, and when the object is
instantiated, the table is queried and the default dict values are
overwritten.  so obviously this method is not going to work as such..

sorry for the misdirection, i didn't quite understand at first..

- m@