Dynamically determine base classes on instantiation

[Steven D'Aprano]

On Thu, 16 Aug 2012 19:18:18 +0200, Thomas Bach wrote:

> Imagine you have two data sets:
> 
> d1 = {'foo': None}
> d2 = {'foo': 8}
> 
> Where I would assume that d1 has "foo" not set. That's why I want this
> whole "merge"-thing in the first place: to be able to extract the type
> {'foo': None} from d1 and {'foo': int} from d2 and merge the two
> together which should result in {'foo': int}.

That becomes trivial if you do the merge before converting to types:

d3 = d1.copy()  # the merged dict
for key, value in d2.items():
    if key in d1 and d1[key] is None:
        d3[key] = value  # merge

Now pass d3 to your recursive_type function.


-- 
Steven