1st Sketch at at ReadOnly dict

[Dan Stromberg]

On Mon, Jan 20, 2014 at 12:09 PM, Charles Hixson
<charleshixsn at earthlink.net> wrote:

> class RODict:
>     #Instance Variable Doc
>     ##    @var    _ddict
>     #        This variable holds the reference to the dict.
>
>     ##    Class initializer.
>     #    @param    ddict    The data dictionary to which this is a read only
>     #            access.
>     #    @throws    TypeError if ddict is not a dict.
>     def __init__ (self, ddict = {}):
>         if not isinstance(ddict, dict):
>             raise    TypeError("ddict must be a dict.  It is " +
> repr(ddict))
>         self._ddict    =    ddict

When I see this isinstance, I think "Gee, that means none of the
dict-like-objects I recently compared would work with this class."

The comparison is at the URL below; all the things compared are trees
that provide a dictionary-like interface, but also find_min, find_max
and can iterate in key order.  I don't think any of them inherit from
dict, but they are all dict-like in a duck-typed sense:

http://stromberg.dnsalias.org/~strombrg/python-tree-and-heap-comparison/2014-01/

HTH