keras-team/keras · error · ValueError

`pool_size` must be a tuple of 2 integers.

Error message

`pool_size` must be a tuple of 2 integers.

What it means

Error "`pool_size` must be a tuple of 2 integers." thrown in keras-team/keras.

Source

Thrown at keras/src/legacy/backend.py:1099

    return tf.transpose(x, perm=pattern)


@keras_export("keras._legacy.backend.pool2d")
def pool2d(
    x,
    pool_size,
    strides=(1, 1),
    padding="valid",
    data_format=None,
    pool_mode="max",
):
    """DEPRECATED."""
    if data_format is None:
        data_format = backend.image_data_format()
    if data_format not in {"channels_first", "channels_last"}:
        raise ValueError(f"Unknown data_format: {data_format}")
    if len(pool_size) != 2:
        raise ValueError("`pool_size` must be a tuple of 2 integers.")
    if len(strides) != 2:
        raise ValueError("`strides` must be a tuple of 2 integers.")

    x, tf_data_format = _preprocess_conv2d_input(x, data_format)
    padding = _preprocess_padding(padding)
    if tf_data_format == "NHWC":
        strides = (1,) + strides + (1,)
        pool_size = (1,) + pool_size + (1,)
    else:
        strides = (1, 1) + strides
        pool_size = (1, 1) + pool_size

    if pool_mode == "max":
        x = tf.compat.v1.nn.max_pool(
            x, pool_size, strides, padding=padding, data_format=tf_data_format
        )
    elif pool_mode == "avg":
        x = tf.compat.v1.nn.avg_pool(

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/legacy/backend.py:1099 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/9861e16fa69f211a. Report an issue: GitHub.