fix: do not expose an rdfentry_ column

[ianna]

Fixes unintentional exposure of an rdfentry_ column. There is no test to check it, but current documentation shows that an rdfentry_ column was exposed:

array = ak.from_rdataframe(
    df,
    columns=(
        "x",
        "y",
        "z",
    ),
)
array

[{y: 1, z: [1.1], rdfentry_: [0, 1, 2, 3, 4], x: {...}},
 {y: 2, z: [2.1, 2.3, 2.4], rdfentry_: [0, 1, ..., 3, 4], x: {...}},
 {y: 3, z: [3.1], rdfentry_: [0, 1, 2, 3, 4], x: {...}},
 {y: 4, z: [4.1, 4.2, 4.3], rdfentry_: [0, 1, ..., 3, 4], x: {...}},
 {y: 5, z: [5.1], rdfentry_: [0, 1, 2, 3, 4], x: {...}}]
--------------------------------------------------------------------
type: 5 * {
    y: int64,
    z: var * float64,
    rdfentry_: var * int64,
    x: {
        x: var * float64
    }
}

[codecov]

Codecov Report

Merging #2343 (a789288) into main (1f70725) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

Additional details and impacted files

Impacted Files	Coverage Δ
src/awkward/_connect/numexpr.py	90.27% <ø> (ø)
src/awkward/_connect/rdataframe/from_rdataframe.py	0.00% <0.00%> (ø)
src/awkward/highlevel.py	75.79% <0.00%> (-0.25%)	⬇️

[jpivarski]

This is good—separating the index out into something distinct from columns, as it would be in (for example) Pandas.

Merge the branch whenever you're ready!

[jpivarski]

This is good—separating the index out into something distinct from columns, as it would be in (for example) Pandas.

Merge the branch whenever you're ready!