List of dynamic Enums can contain anything

[k2bd]

Traits 5.1.2-1

MWE:

from traits.api import HasTraits, Enum, List


class MyClass(HasTraits):
    vals = ["a", "b"]

    list_enum = List(Enum(values="vals"))


my_obj = MyClass()

my_obj.list_enum = ["c", None, MyClass()]
my_obj.list_enum.append(1)

print(my_obj.list_enum)
# ['c', None, <__main__.MyClass object at 0x1157010a0>, 1]

[rkern]

Yes, the dynamic-valued Enum has an odd implementation. It basically disables the validate method and handles the validation in an ad hoc manner in the setter, which is not what is used when it's an inner trait inside of List.

[pzahemszky]

As Robert was saying, this issue only affects dynamic-valued Enums:

from traits.api import HasTraits, Enum, List

vals = ["a", "b"]


class MyClass(HasTraits):

    list_enum = List(Enum(vals))


my_obj = MyClass()

my_obj.list_enum = ["c", None, MyClass()]
# traits.trait_errors.TraitError: Each element of the 'list_enum' trait
# of a MyClass instance must be 'a' or 'b', but a value of 'c'
# <class 'str'> was specified

I slightly changed the title to show this.

[mdickinson]

This was fixed in #1388.