`set` allowed for `index` argument in `Series`, `index` and `columns` for `DataFrame.from_records()`

[Dr-Irv]

In #47215 I brought up the issue of allowing sets as arguments for the DataFrame constructor. This was addressed in #47231 . But there are a few more cases that should be fixed:

>>> pd.Series([3,4,5], index=set(["a", "b", "c"]))
c    3
a    4
b    5
dtype: int64
>>> pd.DataFrame.from_records([[1,2,3]], columns=set(["a", "b", "c"]), index=set(["x", "y", "z"]))
   c  a  b
x  1  2  3
y  1  2  3
z  1  2  3

We shouldn't allow a set as an argument for index or columns in both these cases.

[lithomas1]

Do we need a deprecation for this, or is it OK to do as a breaking change like the previous PR?

[Dr-Irv]

Do we need a deprecation for this, or is it OK to do as a breaking change like the previous PR?

I think a breaking change is fine.

[Dr-Irv]

Also do we want to disallow views on dicts?

>>> data =[1, 2, 3]
>>> data
[1, 2, 3]
>>> d = {'a'+str(value): value for value in data}
>>> d
{'a1': 1, 'a2': 2, 'a3': 3}
>>> pd.Series(d.values(), index=d.keys())
a1    1
a2    2
a3    3
dtype: int64

The above works, but strictly speaking, d.keys() and d.values() are not array-like, so maybe we should also test if instances of MappingView are passed and reject them?

If we agree those shouldn't be allowed, that might require a deprecation cycle.

[Dr-Irv]

Also, for Series(), the docs say that we accept an Iterable, but we don't accept all Iterable as values, e.g. sets. So we should adjust the docs as well.

[Dr-Irv]

Here's another one. I think that sets shouldn't be allowed as the argument when constructing an Index:

>>> pd.Index(set([1,2]))
Index([1, 2], dtype='int64')
>>> pd.Index(set([2,1]))
Index([1, 2], dtype='int64')

The order of the Index is ambiguous when you pass a set argument.

[Dr-Irv]

Similar question about using a dict as argument to Index. Should this work:

pd.Index({"a":1, "b":2})

If yes, we should update the docs. If not, then we should check for it. Same goes for any of the subclasses of Index

[Dr-Irv]

Agreed in dev meeting on 2/12 that we don't want to accept set and be explicit about what we take.

Related comment: #54176 (comment)