keras-team/keras · error · ValueError

`padding` should have 3 elements. Received: {padding}.

Error message

`padding` should have 3 elements. Received: {padding}.

What it means

Error "`padding` should have 3 elements. Received: {padding}." thrown in keras-team/keras.

Source

Thrown at keras/src/layers/reshaping/zero_padding3d.py:73

        - If `data_format` is `"channels_first"`:
          `(batch_size, depth, first_padded_axis, second_padded_axis,
          third_axis_to_pad)`
    """

    def __init__(
        self, padding=((1, 1), (1, 1), (1, 1)), data_format=None, **kwargs
    ):
        super().__init__(**kwargs)
        self.data_format = backend.standardize_data_format(data_format)
        if isinstance(padding, int):
            self.padding = (
                (padding, padding),
                (padding, padding),
                (padding, padding),
            )
        elif hasattr(padding, "__len__"):
            if len(padding) != 3:
                raise ValueError(
                    f"`padding` should have 3 elements. Received: {padding}."
                )
            dim1_padding = argument_validation.standardize_tuple(
                padding[0], 2, "1st entry of padding", allow_zero=True
            )
            dim2_padding = argument_validation.standardize_tuple(
                padding[1], 2, "2nd entry of padding", allow_zero=True
            )
            dim3_padding = argument_validation.standardize_tuple(
                padding[2], 2, "3rd entry of padding", allow_zero=True
            )
            self.padding = (dim1_padding, dim2_padding, dim3_padding)
        else:
            raise ValueError(
                "`padding` should be either an int, a tuple of 3 ints "
                "(symmetric_dim1_pad, symmetric_dim2_pad, symmetric_dim3_pad), "
                "or a tuple of 3 tuples of 2 ints "
                "((left_dim1_pad, right_dim1_pad),"

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/reshaping/zero_padding3d.py:73 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/dd17b541286887e7. Report an issue: GitHub.