Expandable 2D Dictionaries?

Robert Dailey rcdailey at gmail.com
Fri Jul 6 12:00:07 EDT 2007

On Jul 6, 10:54 am, "Diez B. Roggisch" <d... at nospam.web.de> wrote:
> Robert Dailey wrote:
> > Hi,
> > I am interested in creating an expandable (dynamic) 2D dictionary. For
> > example:
> > myvar["cat"]["paw"] = "Some String"
> > The above example assumes "myvar" is declared. In order for this to
> > work, I have to know ahead of time the contents of the dictionary. For
> > the above to work, my declaration must look like:
> > myvar = {"cat": {"paw":""} }
> > I would like to not have to declare my dictionary like this, as it
> > does not allow it to be expandable. I'm very new to Python (I'm a
> > professional C++ programmer. Any comparisons to C++ would help me
> > understand concepts).
> > Is there a way that when I index into my dictionary using an "unknown"
> > index (string), that python will dynamically add that key/value pair?
> Not really, unless you know that the first level of values are _always_
> dicts.
> What you can do is to use
> myvar.setdefault('cat', {})['paw'] = "Some String"
> Diez

Could you emphasize what you mean by "unless you know that the first
level of values are _always_ dicts."?

Could I create a class wrapper that automates this? I could have an
insert() method of some sort. However I would have to research if it's
possible to overload operators in python.

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