Method __setitem__

tables/vlarray.py:742–807

Set a row, or set of rows, in the array. It takes different actions depending on the type of the *key* parameter: if it is an integer, the corresponding table row is set to *value* (a record or sequence capable of being converted to the table structure). If *key* is

(
        self,
        key: int | slice | Sequence[int] | np.ndarray,
        value: Any,
    )

                self._modify(nrow, nparr, nobjects)

    def __setitem__(
        self,
        key: int | slice | Sequence[int] | np.ndarray,
        value: Any,
    ) -> None:
        """Set a row, or set of rows, in the array.

        It takes different actions depending on the type of the *key*
        parameter: if it is an integer, the corresponding table row is
        set to *value* (a record or sequence capable of being converted
        to the table structure).  If *key* is a slice, the row slice
        determined by it is set to *value* (a record array or sequence
        of rows capable of being converted to the table structure).

        In addition, NumPy-style point selections are supported.  In
        particular, if key is a list of row coordinates, the set of rows
        determined by it is set to value.  Furthermore, if key is an array of
        boolean values, only the coordinates where key is True are set to
        values from value.  Note that for the latter to work it is necessary
        that key list would contain exactly as many rows as the table has.

        .. note::

            When updating the rows of a VLArray object which uses a
            pseudo-atom, there is a problem: you can only update values
            with *exactly* the same size in bytes than the original row.
            This is very difficult to meet with object pseudo-atoms,
            because :mod:`pickle` applied on a Python object does not
            guarantee to return the same number of bytes than over another
            object, even if they are of the same class.
            This effectively limits the kinds of objects than can be
            updated in variable-length arrays.

        Examples
        --------
        ::

            vlarray[0] = vlarray[0] * 2 + 3
            vlarray[99] = arange(96) * 2 + 3

            # Negative values for the index are supported.
            vlarray[-99] = vlarray[5] * 2 + 3
            vlarray[1:30:2] = list_of_rows
            vlarray[[1,3]] = new_1_and_3_rows

        """
        self._g_check_open()
        self._v_file._check_writable()

        if is_idx(key):
            # If key is not a sequence, convert to it
            coords = [key]
            value = [value]
        elif isinstance(key, slice):
            start, stop, step = self._process_range(
                key.start, key.stop, key.step
            )
            coords = range(start, stop, step)