Fix IDView.ids type

[leotrs]

Currently, H.edges.ids sometimes returns a dict and sometimes returns a set:

>>> import xgi
>>> H  = xgi.Hypergraph([{1, 2, 3}, {4}, {5, 6}, {6, 7, 8}])
>>> H.edges.ids
{0: {1, 2, 3}, 1: {4}, 2: {5, 6}, 3: {6, 7, 8}}
>>> H.edges({0, 1, 2}).ids
{0, 1, 2}

This is terrible. Furthermore, the dict version can be obtained via members:

>>> H.edges.members(dtype=dict)
{0: {1, 2, 3}, 1: {4}, 2: {5, 6}, 3: {6, 7, 8}}

This PR makes it so that it always returns a set.

>>> import xgi
>>> H  = xgi.Hypergraph([{1, 2, 3}, {4}, {5, 6}, {6, 7, 8}])
>>> H.edges.ids
{0, 1, 2, 3}

I also added a couple of tests and changed an old test that relied on ids returning a dict (yuck).

[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.02 🎉

Comparison is base (6f04d2f) 90.95% compared to head (24b6c73) 90.97%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #406      +/-   ##
==========================================
+ Coverage   90.95%   90.97%   +0.02%     
==========================================
  Files          47       47              
  Lines        3893     3891       -2     
==========================================
- Hits         3541     3540       -1     
+ Misses        352      351       -1     

Impacted Files	Coverage Δ
xgi/classes/reportviews.py	94.05% <100.00%> (+0.47%)	⬆️

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[nwlandry]

Nice work! Can you comment on Issue #362? For now maybe you could remove the comment in the notebook about order being preserved?

[leotrs]

@nwlandry done!

[nwlandry]

Looks good to me! :)

[nwlandry]

Okay, one more thing. I noticed that in the constructor of IDView, self._ids doesn't have to be a set (line 91). Can you fix that before merging?

[leotrs]

Could you be more specific? L91 and subsequent lines guarantee that self._ids is always set, regardless of the value of ids.

[nwlandry]

Could you be more specific? L91 and subsequent lines guarantee that self._ids is always set, regardless of the value of ids.

In this PR, I don't believe that self._ids is always a set if you construct an IDView with a) ids=None or b) (for example) ids=[1, 2, 3]. I would do something like

self._ids = set(self._id_dict) if ids is None else self._ids = set(ids)

on L91, to enforce this.

[leotrs]

Perhaps we're not seeing the same code? On this PR, L91 and subsequent lines look like this:

        if ids is None:
            self._ids = self._id_dict
        else:
            self._ids = ids

[nwlandry]

I tried out a few things and I was mistaken. I take back my prior comment :)