get_class_by_table should provide list of found classes when

[lachaib]

Hello,

I'm using get_class_by_table method to find the declarative base associated to a table object, without any data associated (trying to export a list of tables associated to the files they are defined in).
In case of polymorphic tables, this method raises a ValueError that multiple classes are found for the table. Although I totally understand this error, I think it would be valuable for at least the exception to be decorated with the multiple results, so that client code may do a follow-up process accordingly with all matching classes.

Something such as

class PolymorphicIndeterminationError(ValueError):
    def __init__(self, message,  polymorphic_classes):
           super().__init__(message)
           self.polymorphic_classes = polymorphic_classes

and then raise PolymorphicIndeterminationError instead of ValueError.

An alternative that may be enough in my case would be to add a parameter only_polymorphic_base to the method, and return only the class that has base in its direct __bases__

I don't know which option would be preferred, but I think this could be a great improvement.

Thanks