Feature Discussion: More granular `skip_exc` in `Coalesce` about glom HOT 2 OPEN

Have you considered Or(Match(structure), default)?

Match is specifically designed for checking structure in a flexible and concise way.

edit: docs https://glom.readthedocs.io/en/latest/matching.html

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For the exact example you gave:

good_data = {"a": {"c": 1}}
bad_data = {"a": [{"c": 1}]}

The reason PathAccessError gave ValueError is that "a" and "b" are being interpreted as Paths -- you could do "a.b" instead of ("a", "b") and get the exact same result. As a Path, "a.0.c" will unpack the bad-data. When it sees a list in the target, it tries to parse the corresponding Path segment as an int to use as the list index.

This can be made less ambiguous by using glom.T. T["a"]["b"] will try to do __getitem__() in both cases.

Although, still I think that Match is really the bigger brother of Coalesce and probably what you want.

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