I have to say I agree with Neil here. I was trying to think about what other reasons an attribute might be unsettable, and did not quickly come up with that list.

And after reading your list, I tried to imagine what I’d tell my beginning students ! 

But if the error message is indeed unique then yes:

 "can't set property 'f'" 

Would be far more clear message. 

-CHB

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Christopher Barker, PhD (Chris)

Python Language Consulting
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