Repository: pandas-dev/pandas
File: pandas/core/indexes/base.py (Python)

Code before:
    ) -> type[libindex.IndexEngine | libindex.ExtensionEngine]:
        return self._engine_types.get(self.dtype, libindex.ObjectEngine)

    # whether we support partial string indexing. Overridden
    # in DatetimeIndex and PeriodIndex
    _supports_partial_string_indexing = False

    _accessors = {"str"}

    str = Accessor("str", StringMethods)

    _references: BlockValuesRefs | None = None

    # --------------------------------------------------------------------
    # Constructors

    def __new__(
        cls,
        data=None,
        dtype=None,
        copy: bool | None = None,
        name=None,
        tupleize_cols: bool = True,
    ) -> Self:
        from pandas.core.indexes.range import RangeIndex

        name = maybe_extract_name(name, data, cls)

        if dtype is not None:
            dtype = pandas_dtype(dtype)

        data_dtype = getattr(data, "dtype", None)

        refs = None
        if not copy and isinstance(data, (ABCSeries, Index)):
            refs = data._references

        # range
        if isinstance(data, (range, RangeIndex)):
            result = RangeIndex(start=data, copy=bool(copy), name=name)
            if dtype is not None:
                return result.astype(dtype, copy=False)
            # error: Incompatible return value type (got "MultiIndex",
            # expected "Self")
            return result  # type: ignore[return-value]

        elif is_ea_or_datetimelike_dtype(dtype):
            # non-EA dtype indexes have special casting logic, so we punt here
            if isinstance(data, (set, frozenset)):
                data = list(data)


Review comment (suggestion):
You can also use the updated description in the Series docstring as a starting point to update the docstring here as well (as the end goal should be to make it similar)

Code after:
    }

    @property
    def _engine_type(
        self,
    ) -> type[libindex.IndexEngine | libindex.ExtensionEngine]:
        return self._engine_types.get(self.dtype, libindex.ObjectEngine)

    # whether we support partial string indexing. Overridden
    # in DatetimeIndex and PeriodIndex
    _supports_partial_string_indexing = False

    _accessors = {"str"}

    str = Accessor("str", StringMethods)

    _references: BlockValuesRefs | None = None

    # --------------------------------------------------------------------
    # Constructors

    def __new__(
        cls,
        data=None,
        dtype=None,
        copy: bool | None = None,
        name=None,
        tupleize_cols: bool = True,
    ) -> Self:
        from pandas.core.indexes.range import RangeIndex

        name = maybe_extract_name(name, data, cls)

        if dtype is not None:
            dtype = pandas_dtype(dtype)

        data_dtype = getattr(data, "dtype", None)

        refs = None
        if not copy and isinstance(data, (ABCSeries, Index)):
            refs = data._references

        if isinstance(data, (ExtensionArray, np.ndarray)):
            # GH 63306
            if copy is not False:
                if dtype is None or astype_is_view(data.dtype, dtype):
                    data = data.copy()
                    copy = False

        # range
        if isinstance(data, (range, RangeIndex)):