Unexpected Python Behavior

[Fredrik Lundh]

Simon Wittber wrote:

> It took me a while to work out that default keyword argument values
> are likely only evaluated once, which caused the empty dict to be
> shared across classes...

some relevant links:

    http://www.python.org/doc/faq/general.html#why-are-default-values-shared-between-objects
    http://docs.python.org/tut/node6.html#SECTION006710000000000000000
    http://docs.python.org/ref/function.html

> It certainly something newbie python coders should look out for!

it's a well-known "you'll only do this once" mistake.  which is a good thing,
because when you understand why this happens, you have learned a lot about
how "def" and objects work in Python...

</F>