keras-team/keras · error · ValueError

`padding` should be either an int, a tuple of 2 ints (symmet

Error message

`padding` should be either an int, a tuple of 2 ints (symmetric_height_crop, symmetric_width_crop), or a tuple of 2 tuples of 2 ints ((top_crop, bottom_crop), (left_crop, right_crop)). Received: padding={padding}.

What it means

Error "`padding` should be either an int, a tuple of 2 ints (symmetric_height_crop, symmetric_width_crop), or a tuple of 2 tuples of 2 ints ((top_crop, bottom_crop), (left_crop, right_crop)). Received: padding={padding}." thrown in keras-team/keras.

Source

Thrown at keras/src/layers/reshaping/zero_padding2d.py:90

        super().__init__(**kwargs)
        self.data_format = backend.standardize_data_format(data_format)
        if isinstance(padding, int):
            self.padding = ((padding, padding), (padding, padding))
        elif hasattr(padding, "__len__"):
            if len(padding) != 2:
                raise ValueError(
                    "`padding` should have two elements. "
                    f"Received: padding={padding}."
                )
            height_padding = argument_validation.standardize_tuple(
                padding[0], 2, "1st entry of padding", allow_zero=True
            )
            width_padding = argument_validation.standardize_tuple(
                padding[1], 2, "2nd entry of padding", allow_zero=True
            )
            self.padding = (height_padding, width_padding)
        else:
            raise ValueError(
                "`padding` should be either an int, a tuple of 2 ints "
                "(symmetric_height_crop, symmetric_width_crop), "
                "or a tuple of 2 tuples of 2 ints "
                "((top_crop, bottom_crop), (left_crop, right_crop)). "
                f"Received: padding={padding}."
            )
        self.input_spec = InputSpec(ndim=4)

    def compute_output_shape(self, input_shape):
        output_shape = list(input_shape)
        spatial_dims_offset = 2 if self.data_format == "channels_first" else 1
        for index in range(0, 2):
            if output_shape[index + spatial_dims_offset] is not None:
                output_shape[index + spatial_dims_offset] += (
                    self.padding[index][0] + self.padding[index][1]
                )
        return tuple(output_shape)

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/reshaping/zero_padding2d.py:90 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/8cf67baebc0062f2. Report an issue: GitHub.