Of course, I forgot to mention that you can use tuples as dictionary keys.
A common idiom is:
pdb[(dataset, modulename, parametername, 'value')] = value.
And if that works for you, it's much simpler. But you lose the ability to
use, say, pdb[dataset][modulename] as a dictionary on its own.
Remco
On Jan 24, 2008 8:20 AM, Garry Willgoose <[EMAIL PROTECTED]>
wrote:
> Is there any easy way to create a nested dictionary. I want to be
> able to allocate like
>
> pdb[dataset][modulename][parametername]['value']=value
>
> where dataset, modulename, parametername are variables that are
> determined within loops nested 3 deep, and value comes from a
> database call. Prior to the nested loops I do not know what the
> values of dataset, modulename, parametername will range over, but I
> do know pdb needs to be nested 3 deep. What I'd like to do is
> something like this
>
> pdb={}
> for dataset in dataset_list:
> modulename_list=getmodules(dataset)
> for modulename in modulename_list:
> parametername_list=getparameters(dataset,modulename)
> for parametername in parametername_list:
> value=getvalue(dataset, modulename, parametername)
>
> pdb[dataset][modulename][parametername]['value']=value
>
> What I'm currently doing is
>
> pdb={}
> for dataset in dataset_list:
> modulename_list=getmodules(dataset)
> moduledict={}
> for modulename in modulename_list:
> parametername_list=getparameters(dataset,modulename)
> valuedict={}
> for parametername in parametername_list:
> value=getvalue(dataset, modulename, parametername)
> valuedict['value']=value
> # valuedict needs to be a dictionary because there is other stuff
> valuedict['otherstuff]=otherstuff
> ...
> parameterdict[parametername]=valuedict.copy()
> moduledict[modeulename]=copy.deepcopy(parameterdict)
> pdb[dataset]=copy.deepcopy(moduledict)
>
>
> Now I know the 2nd is not that much more complex but this is a pretty
> common construct in what I'm doing so I'm just wondering if there is
> a clear and simple shortcut ;-)
>
>
> ====================================================================
> Prof Garry Willgoose,
> Australian Professorial Fellow in Environmental Engineering,
> Director, Centre for Climate Impact Management (C2IM),
> School of Engineering, The University of Newcastle,
> Callaghan, 2308
> Australia.
>
> Centre webpage: www.c2im.org.au
>
> Phone: (International) +61 2 4921 6050 (Tues-Fri AM); +61 2 6545 9574
> (Fri PM-Mon)
> FAX: (International) +61 2 4921 6991 (Uni); +61 2 6545 9574 (personal
> and Telluric)
> Env. Engg. Secretary: (International) +61 2 4921 6042
>
> email: [EMAIL PROTECTED];
> [EMAIL PROTECTED]
> email-for-life: [EMAIL PROTECTED]
> personal webpage: www.telluricresearch.com/garry
> ====================================================================
> "Do not go where the path may lead, go instead where there is no path
> and leave a trail"
> Ralph Waldo Emerson
> ====================================================================
>
>
>
>
>
> _______________________________________________
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>
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