Incorrect return type in QueryDict.items()/values() docs examples

[Daniel F Moisset]

There is an inconsistency about the defined behaviour of QueryDict.items() (a similar thing happens for QueryDict.values():

• The ​current implementation actually returns a generator object (supporting iteration only)
• The ​documentation says that it is "just like the standard dictionary items() method", which in Python3 returns a dict_items object (a ​view object, supporting set-like operations)
• But the example in the documentation 2 lines below that show a standard python list (supporting indexing)

I see 2 different was to fix this:

1. Update the documentation and make explicit that a generator is returned and that Querydict is a bit different than python dicts
2. Make QueryDict behave more like python by returning a set(). This should not break backwards compatibility (a set is more general than a generator), but use more memory (because the set must be fully built instead of generated lazily)

I can provide patches for any of these options, but some core devs recommended me getting an opinion of which is the right solution before moving forward.

[Tim Graham]

Fixing the documentation looks like the correct way to proceed. The current example shows the behavior on Python 2 was was ​to return a list.

[Daniel F Moisset]

Thank you, created a PR: ​https://github.com/django/django/pull/8320

[Tim Graham <timograham@…>]

In 8ab7ce85:

Fixed #28037 -- Clarified that QueryDict.items()/values() are generators.