Inconsistent behaviour between dict.items and dict.values

Question

_{Note: code examples in python3, but the question stands for python2 as well (replacing .keys with .viewkeys, etc)}<

Answer 1

The reason is that it's not implemented in the dict_values type or because the dict_values class specifically disallows it.

Since your values are generally a non-unique list of items it's not a great idea to convert it to a set. If you do want that, just manually convert it. My assumption is that it's disallowed since it's generally a bad idea as it can cause data loss.