Allow Any type to be used as an escape hatch
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evansd
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inglesp
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| @@ -20,7 +20,7 @@ | |||
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| class PickOneRowPerPatientWithColumns(PickOneRowPerPatient): | |||
| selected_columns: frozenset[Any] | |||
| selected_columns: Any | |||
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I think this could do with a comment to say that what the type should be, but that we can't easily enforce it.
This fixes a bug whereby attempting to select two columns of different types following a pick-one-row operation blows up with a type error. The issue is that when we construct the internal query model node `PickOoneRowPerPatientWithColumns` we collect the selected column objects into a frozenset and make that a node attribute. Then, during type validation, we call `get_typespec()` on this attribute to determine its type specification. But this can't cope with sets containing more than one type (e.g. `Series[bool]` and `Series[date]`) so it blows up. We _could_ teach `get_typespec()` to be cleverer and work out the common ancestor class for heterogeneous sets like this. But that involves adding complexity to an already very complex system and I'm not sure there's sufficient benefit here. While strict type checking is essential for the public surface of the query model, I don't think it's so essential for the purely internal classes. So instead we just ensure that the `Any` type functions as an escape hatch which shortcuts all the type checking behaviour and change the type annotation of the problematic attribute to `Any`.
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I should have done this as part of the original PR.
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This fixes a bug whereby attempting to select two columns of different types following a pick-one-row operation blows up with a type error.
The issue is that when we construct the internal query model node
PickOoneRowPerPatientWithColumnswe collect the selected column objects into a frozenset and make that a node attribute. Then, during type validation, we callget_typespec()on this attribute to determine its type specification. But this can't cope with sets containing more than one type (e.g.Series[bool]andSeries[date]) so it blows up.We could teach
get_typespec()to be cleverer and work out the common ancestor class for heterogeneous sets like this. But that involves adding complexity to an already very complex system and I'm not sure there's sufficient benefit here. While strict type checking is essential for the public surface of the query model, I don't think it's so essential for the purely internal classes.So instead we just ensure that the
Anytype functions as an escape hatch which shortcuts all the type checking behaviour and change the type annotation of the problematic attribute toAny.