Function ndarray_to_mgr

pandas/core/internals/construction.py:193–354

(
    values, index, columns, dtype: DtypeObj | None, copy: bool
)

def ndarray_to_mgr(
    values, index, columns, dtype: DtypeObj | None, copy: bool
) -> Manager:
    # used in DataFrame.__init__
    # input must be an ndarray, list, Series, Index, ExtensionArray
    infer_object = not isinstance(values, (ABCSeries, Index, ExtensionArray))

    if isinstance(values, ABCSeries):
        if columns is None:
            if values.name is not None:
                columns = Index([values.name])
        if index is None:
            index = values.index
        else:
            values = values.reindex(index)

        # zero len case (GH #2234)
        if not len(values) and columns is not None and len(columns):
            values = np.empty((0, 1), dtype=object)

    vdtype = getattr(values, "dtype", None)
    refs = None
    if is_1d_only_ea_dtype(vdtype) or is_1d_only_ea_dtype(dtype):
        # GH#19157

        if isinstance(values, (np.ndarray, ExtensionArray)) and values.ndim > 1:
            # GH#12513 an EA dtype passed with a 2D array, split into
            #  multiple EAs that view the values
            # error: No overload variant of "__getitem__" of "ExtensionArray"
            # matches argument type "Tuple[slice, int]"
            values = [
                values[:, n]  # type: ignore[call-overload]
                for n in range(values.shape[1])
            ]
        else:
            values = [values]

        # Handle copy semantics: already copy 1d-only EA. Other arrays will
        # be copied when consolidating the blocks
        if copy:
            values = [
                (x.copy(deep=True) if isinstance(x, Index) else x.copy())
                if isinstance(x, (ExtensionArray, Index, ABCSeries))
                and is_1d_only_ea_dtype(x.dtype)
                else x
                for x in values
            ]

        if columns is None:
            columns = Index(range(len(values)))
        else:
            columns = ensure_index(columns)

        return arrays_to_mgr(values, columns, index, dtype=dtype, consolidate=copy)

    if isinstance(values, (ABCSeries, Index)):
        if not copy and (dtype is None or astype_is_view(values.dtype, dtype)):
            refs = values._references