keyword arguments and **

[Boudewijn Rempt]

<posted & mailed>

Alex Martelli wrote:

> 
> Usual problem: when an argument (here, fields) has a default
> value that is mutable, that value is determined ONCE, when the
> def statement executes -- then that single value stays around
> (the function object references it), and if you mutate it you
> get such a "memory effect".
> 
> Usual fix:
> 
>>>> def f(fields=None, **args):
>  ...     if fields is None: fields = {}
>  ...     print fields
>  ...     fields.update(args)
>  ...     print "XXX", fields
> 

Thanks. I feel even sillier now :-).

-- 
Boudewijn Rempt | http://www.valdyas.org