2020-12-28 Christopher Barker <python...@gmail.com> dixit:
> I don't know about the OP, but all I wanted was a clear definition of
> the part of the API needed to support **, and apparently it's a
> keys() method that returns an iterator of the keys, and a __getitem__
[...]
To be more precise: an *iterable* of the keys -- not necessarily an
*iterator*; it can be, for example, a list or string:
>>> def fun(**kwargs):print(kwargs)
...
>>> class C:
... def keys(self): return list('abc')
... def __getitem__(self, key): return 42
...
>>> c = C()
>>> fun(**c)
{'a': 42, 'c': 42, 'b': 42}
And, even, the `keys()` method does not need to be defined on the
class level -- it can be a callable attribute of an *instance*:
>>> class D:
... def __getitem__(self, key): return 42
...
>>> d = D()
>>> d.keys = lambda: 'abc'
>>> fun(**d)
{'a': 42, 'c': 42, 'b': 42}
Cheers,
*j
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