namespace dictionaries ok?

[Bengt Richter]

On Tue, 25 Oct 2005 03:10:17 GMT, Ron Adam <rrr at ronadam.com> wrote:

>Simon Burton wrote:
>
>> Yes!
>> 
>> I do this a lot when i have deeply nested function calls
>> a->b->c->d->e
>> and need to pass args  to the deep function without changing the
>> middle functions.
>
>Yes, :-)  Which is something like what I'm doing also.  Get the 
>dictionary, modify it or validate it somehow, then pass it on.  I also 
>find that when I'm passing variables as keywords,
>
>      foo(name=name, address=address, city=city)
>
>I really don't want (or like) to have to access the names with 
>dictionary key as *strings* in the function that is called and collects 
>them in a single object.
>
>
>> In this situation I think i would prefer this variation:
>> 
>> class Context(dict):
>>   def __init__(self,**kwds):
>>     dict.__init__(self,kwds)
>>   def __getattr__(self, name):
>>     return self.__getitem__(name)
>>   def __setattr__(self, name, value):
>>     self.__setitem__(name, value)
>>   def __delattr__(self, name):
>>     self.__delitem__(name)
> >
>> def foo(ctx):
>>    print ctx.color, ctx.size, ctx.shape
>> 
>> foo( Context(color='red', size='large', shape='ball') )
>> 
>> 
>> This is looking like foo should be a method of Context now,
>> but in my situation foo is already a method of another class.
>>
Or maybe just add a __repr__ method, if you want to see a readable
representation (e.g., see below). 
>> Simon.
>
>I didn't see what you were referring to at first.  But yes, I see the 
>similarity.
>
 >>> class Context(dict):
 ...   def __init__(self,**kwds):
 ...     dict.__init__(self,kwds)
 ...   def __getattr__(self, name):
 ...     return self.__getitem__(name)
 ...   def __setattr__(self, name, value):
 ...     self.__setitem__(name, value)
 ...   def __delattr__(self, name):
 ...     self.__delitem__(name)
 ...   def __repr__(self):
 ...     return 'Context(%s)' % ', '.join('%s=%r'% t for t in sorted(self.items()))
 ...
 >>> print Context(color='red', size='large', shape='ball')
 Context(color='red', shape='ball', size='large')
 >>> ctx = Context(color='red', size='large', shape='ball')
 >>> print ctx
 Context(color='red', shape='ball', size='large')
 >>> ctx
 Context(color='red', shape='ball', size='large')
 >>> ctx.color
 'red'

Regards,
Bengt Richter